@tanstack/pacer - npm Package Compare versions

Comparing version 0.3.0 to 0.4.0

dist/cjs/async-debouncer.cjs.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"async-debouncer.cjs","sources":["../../src/async-debouncer.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async debounced function\n */\nexport interface AsyncDebouncerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the debouncer is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute on the leading edge of the timeout.\n   * Defaults to false.\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the debounced function throws\n   */\n  onError?: (error: unknown, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSettled?: (debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSuccess?: (result: ReturnType<TFn>, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Whether to execute on the trailing edge of the timeout.\n   * Defaults to true.\n   */\n  trailing?: boolean\n  /**\n   * Delay in milliseconds to wait after the last call before executing\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncDebouncerOptions<any>> = {\n  enabled: true,\n  leading: false,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async debounced function.\n *\n * Debouncing ensures that a function is only executed after a specified delay has passed since its last invocation.\n * Each new invocation resets the delay timer. This is useful for handling frequent events like window resizing\n * or input changes where you only want to execute the handler after the events have stopped occurring.\n *\n * Unlike throttling which allows execution at regular intervals, debouncing prevents any execution until\n * the function stops being called for the specified delay period.\n *\n * @example\n * ```ts\n * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {\n *   await searchAPI(value);\n * }, { wait: 500 });\n *\n * // Called on each keystroke but only executes after 500ms of no typing\n * inputElement.addEventListener('input', () => {\n *   asyncDebouncer.maybeExecute(inputElement.value);\n * });\n * ```\n */\nexport class AsyncDebouncer<TFn extends AnyAsyncFunction> {\n  private _abortController: AbortController | null = null\n  private _canLeadingExecute = true\n  private _errorCount = 0\n  private _isExecuting = false\n  private _isPending = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastResult: ReturnType<TFn> | undefined\n  private _options: Required<AsyncDebouncerOptions<TFn>>\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncDebouncerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the debouncer options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncDebouncerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this._isPending = false\n    }\n  }\n\n  /**\n   * Returns the current debouncer options\n   */\n  getOptions(): Required<AsyncDebouncerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the debounced function\n   * If a call is already in progress, it will be queued\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this._cancel()\n    this._lastArgs = args\n\n    // Handle leading execution\n    if (this._options.leading && this._canLeadingExecute) {\n      this._canLeadingExecute = false\n      await this.executeFunction(...args)\n      return this._lastResult\n    }\n\n    // Handle trailing execution\n    if (this._options.trailing) {\n      this._isPending = true\n    }\n\n    return new Promise((resolve) => {\n      this._timeoutId = setTimeout(async () => {\n        // Execute trailing if enabled\n        if (this._options.trailing && this._lastArgs) {\n          await this.executeFunction(...this._lastArgs)\n        }\n\n        // Reset state and resolve\n        this._canLeadingExecute = true\n        resolve(this._lastResult)\n      }, this._options.wait)\n    })\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._isPending = false\n      this._settleCount++\n      this._abortController = null\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancel without resetting _canLeadingExecute\n   */\n  private _cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n    this._isPending = false\n    this._isExecuting = false\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    this._canLeadingExecute = true\n    this._cancel()\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns `true` if there is a pending execution queued up for trailing execution\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && this._isPending\n  }\n\n  /**\n   * Returns `true` if there is currently an execution in progress\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async debounced function that delays execution until after a specified wait time.\n * The debounced function will only execute once the wait period has elapsed without any new calls.\n * If called again during the wait period, the timer resets and a new wait period begins.\n *\n * @example\n * ```ts\n * const debounced = asyncDebounce(async (value: string) => {\n *   await saveToAPI(value);\n * }, { wait: 1000 });\n *\n * // Will only execute once, 1 second after the last call\n * await debounced(\"first\");  // Cancelled\n * await debounced(\"second\"); // Cancelled\n * await debounced(\"third\");  // Executes after 1s\n * ```\n */\nexport function asyncDebounce<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncDebouncerOptions<TFn>, 'enabled'>,\n) {\n  const asyncDebouncer = new AsyncDebouncer(fn, initialOptions)\n  return asyncDebouncer.maybeExecute.bind(asyncDebouncer)\n}\n"],"names":[],"mappings":";;AAwCA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AAwBO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAbV,SAAQ,mBAA2C;AACnD,SAAQ,qBAAqB;AAC7B,SAAQ,cAAc;AACtB,SAAQ,eAAe;AACvB,SAAQ,aAAa;AAIrB,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,aAAa;AAAA,IAAA;AAAA,EACpB;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AACtC,SAAK,QAAQ;AACb,SAAK,YAAY;AAGjB,QAAI,KAAK,SAAS,WAAW,KAAK,oBAAoB;AACpD,WAAK,qBAAqB;AACpB,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA;AAIV,QAAA,KAAK,SAAS,UAAU;AAC1B,WAAK,aAAa;AAAA,IAAA;AAGb,WAAA,IAAI,QAAQ,CAAC,YAAY;AACzB,WAAA,aAAa,WAAW,YAAY;AAEvC,YAAI,KAAK,SAAS,YAAY,KAAK,WAAW;AAC5C,gBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,QAAA;AAI9C,aAAK,qBAAqB;AAC1B,gBAAQ,KAAK,WAAW;AAAA,MAAA,GACvB,KAAK,SAAS,IAAI;AAAA,IAAA,CACtB;AAAA,EAAA;AAAA,EAGH,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,QAAgB,QAAA;AAC9B,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACpB,WAAK,aAAa;AACb,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMN,UAAgB;AACtB,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AACjB,SAAK,aAAa;AAClB,SAAK,eAAe;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtB,SAAe;AACb,SAAK,qBAAqB;AAC1B,SAAK,QAAQ;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMf,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACf,WAAA,KAAK,SAAS,WAAW,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMvC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAmBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;;;"}
+{"version":3,"file":"async-debouncer.cjs","sources":["../../src/async-debouncer.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async debounced function\n */\nexport interface AsyncDebouncerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the debouncer is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute on the leading edge of the timeout.\n   * Defaults to false.\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the debounced function throws\n   */\n  onError?: (error: unknown, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSettled?: (debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSuccess?: (result: ReturnType<TFn>, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Whether to execute on the trailing edge of the timeout.\n   * Defaults to true.\n   */\n  trailing?: boolean\n  /**\n   * Delay in milliseconds to wait after the last call before executing\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncDebouncerOptions<any>> = {\n  enabled: true,\n  leading: false,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async debounced function.\n *\n * Debouncing ensures that a function is only executed after a specified delay has passed since its last invocation.\n * Each new invocation resets the delay timer. This is useful for handling frequent events like window resizing\n * or input changes where you only want to execute the handler after the events have stopped occurring.\n *\n * Unlike throttling which allows execution at regular intervals, debouncing prevents any execution until\n * the function stops being called for the specified delay period.\n *\n * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the debounced function.\n *\n * @example\n * ```ts\n * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {\n *   const results = await searchAPI(value);\n *   return results; // Return value is preserved\n * }, { wait: 500 });\n *\n * // Called on each keystroke but only executes after 500ms of no typing\n * // Returns the API response directly\n * const results = await asyncDebouncer.maybeExecute(inputElement.value);\n * ```\n */\nexport class AsyncDebouncer<TFn extends AnyAsyncFunction> {\n  private _abortController: AbortController | null = null\n  private _canLeadingExecute = true\n  private _errorCount = 0\n  private _isExecuting = false\n  private _isPending = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastResult: ReturnType<TFn> | undefined\n  private _options: Required<AsyncDebouncerOptions<TFn>>\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncDebouncerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the debouncer options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncDebouncerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this._isPending = false\n    }\n  }\n\n  /**\n   * Returns the current debouncer options\n   */\n  getOptions(): Required<AsyncDebouncerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the debounced function\n   * If a call is already in progress, it will be queued\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this._cancel()\n    this._lastArgs = args\n\n    // Handle leading execution\n    if (this._options.leading && this._canLeadingExecute) {\n      this._canLeadingExecute = false\n      await this.executeFunction(...args)\n      return this._lastResult\n    }\n\n    // Handle trailing execution\n    if (this._options.trailing) {\n      this._isPending = true\n    }\n\n    return new Promise((resolve) => {\n      this._timeoutId = setTimeout(async () => {\n        // Execute trailing if enabled\n        if (this._options.trailing && this._lastArgs) {\n          await this.executeFunction(...this._lastArgs)\n        }\n\n        // Reset state and resolve\n        this._canLeadingExecute = true\n        resolve(this._lastResult)\n      }, this._options.wait)\n    })\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._isPending = false\n      this._settleCount++\n      this._abortController = null\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancel without resetting _canLeadingExecute\n   */\n  private _cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n    this._isPending = false\n    this._isExecuting = false\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    this._canLeadingExecute = true\n    this._cancel()\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns `true` if there is a pending execution queued up for trailing execution\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && this._isPending\n  }\n\n  /**\n   * Returns `true` if there is currently an execution in progress\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async debounced function that delays execution until after a specified wait time.\n * The debounced function will only execute once the wait period has elapsed without any new calls.\n * If called again during the wait period, the timer resets and a new wait period begins.\n *\n * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the debounced function.\n *\n * @example\n * ```ts\n * const debounced = asyncDebounce(async (value: string) => {\n *   const result = await saveToAPI(value);\n *   return result; // Return value is preserved\n * }, { wait: 1000 });\n *\n * // Will only execute once, 1 second after the last call\n * // Returns the API response directly\n * const result = await debounced(\"third\");\n * ```\n */\nexport function asyncDebounce<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncDebouncerOptions<TFn>, 'enabled'>,\n) {\n  const asyncDebouncer = new AsyncDebouncer(fn, initialOptions)\n  return asyncDebouncer.maybeExecute.bind(asyncDebouncer)\n}\n"],"names":[],"mappings":";;AAwCA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AA4BO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAbV,SAAQ,mBAA2C;AACnD,SAAQ,qBAAqB;AAC7B,SAAQ,cAAc;AACtB,SAAQ,eAAe;AACvB,SAAQ,aAAa;AAIrB,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,aAAa;AAAA,IAAA;AAAA,EACpB;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AACtC,SAAK,QAAQ;AACb,SAAK,YAAY;AAGjB,QAAI,KAAK,SAAS,WAAW,KAAK,oBAAoB;AACpD,WAAK,qBAAqB;AACpB,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA;AAIV,QAAA,KAAK,SAAS,UAAU;AAC1B,WAAK,aAAa;AAAA,IAAA;AAGb,WAAA,IAAI,QAAQ,CAAC,YAAY;AACzB,WAAA,aAAa,WAAW,YAAY;AAEvC,YAAI,KAAK,SAAS,YAAY,KAAK,WAAW;AAC5C,gBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,QAAA;AAI9C,aAAK,qBAAqB;AAC1B,gBAAQ,KAAK,WAAW;AAAA,MAAA,GACvB,KAAK,SAAS,IAAI;AAAA,IAAA,CACtB;AAAA,EAAA;AAAA,EAGH,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,QAAgB,QAAA;AAC9B,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACpB,WAAK,aAAa;AACb,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMN,UAAgB;AACtB,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AACjB,SAAK,aAAa;AAClB,SAAK,eAAe;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtB,SAAe;AACb,SAAK,qBAAqB;AAC1B,SAAK,QAAQ;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMf,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACf,WAAA,KAAK,SAAS,WAAW,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMvC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAuBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;;;"}

dist/cjs/async-debouncer.d.cts

@@ -49,12 +49,16 @@ import { AnyAsyncFunction } from './types.cjs';
  *
+ * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the debounced function.
+ *
  * @example
  * ```ts
  * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {
- *   await searchAPI(value);
+ *   const results = await searchAPI(value);
+ *   return results; // Return value is preserved
  * }, { wait: 500 });
  *
  * // Called on each keystroke but only executes after 500ms of no typing
- * inputElement.addEventListener('input', () => {
- *   asyncDebouncer.maybeExecute(inputElement.value);
- * });
+ * // Returns the API response directly
+ * const results = await asyncDebouncer.maybeExecute(inputElement.value);
  * ```
@@ -129,14 +133,18 @@ */
  *
+ * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the debounced function.
+ *
  * @example
  * ```ts
  * const debounced = asyncDebounce(async (value: string) => {
- *   await saveToAPI(value);
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // Will only execute once, 1 second after the last call
- * await debounced("first");  // Cancelled
- * await debounced("second"); // Cancelled
- * await debounced("third");  // Executes after 1s
+ * // Returns the API response directly
+ * const result = await debounced("third");
  * ```
  */
 export declare function asyncDebounce<TFn extends AnyAsyncFunction>(fn: TFn, initialOptions: Omit<AsyncDebouncerOptions<TFn>, 'enabled'>): (...args: Parameters<TFn>) => Promise<ReturnType<TFn> | undefined>;

dist/cjs/async-rate-limiter.cjs

@@ -12,3 +12,4 @@ "use strict";
   onSuccess: () => {
-  }
+  },
+  windowType: "fixed"
 };
@@ -23,2 +24,3 @@ class AsyncRateLimiter {
     this._successCount = 0;
+    this._isExecuting = false;
     this._options = {
@@ -60,5 +62,15 @@ ...defaultOptions,
     this.cleanupOldExecutions();
-    if (this._executionTimes.length < this._options.limit) {
-      await this.executeFunction(...args);
-      return this._lastResult;
+    if (this._options.windowType === "sliding") {
+      if (this._executionTimes.length < this._options.limit) {
+        await this.executeFunction(...args);
+        return this._lastResult;
+      }
+    } else {
+      const now = Date.now();
+      const oldestExecution = Math.min(...this._executionTimes);
+      const isNewWindow = oldestExecution + this._options.window <= now;
+      if (isNewWindow || this._executionTimes.length < this._options.limit) {
+        await this.executeFunction(...args);
+        return this._lastResult;
+      }
     }
@@ -71,2 +83,3 @@ this.rejectFunction();
     if (!this._options.enabled) return;
+    this._isExecuting = true;
     const now = Date.now();
@@ -82,2 +95,3 @@ this._executionTimes.push(now);
     } finally {
+      this._isExecuting = false;
       this._settleCount++;
@@ -110,5 +124,11 @@ (_f = (_e = this._options).onSettled) == null ? void 0 : _f.call(_e, this);
    * Returns the number of milliseconds until the next execution will be possible
+   * For fixed windows, this is the time until the current window resets
+   * For sliding windows, this is the time until the oldest execution expires
    */
   getMsUntilNextWindow() {
-    return this.getRemainingInWindow() * this._options.window;
+    if (this.getRemainingInWindow() > 0) {
+      return 0;
+    }
+    const oldestExecution = Math.min(...this._executionTimes);
+    return oldestExecution + this._options.window - Date.now();
   }
@@ -140,2 +160,8 @@ /**
   /**
+   * Returns whether the function is currently executing
+   */
+  getIsExecuting() {
+    return this._isExecuting;
+  }
+  /**
    * Resets the rate limiter state
@@ -142,0 +168,0 @@ */

dist/cjs/async-rate-limiter.cjs.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"async-rate-limiter.cjs","sources":["../../src/async-rate-limiter.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async rate-limited function\n */\nexport interface AsyncRateLimiterOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Optional error handler for when the rate-limited function throws\n   */\n  onError?: (error: unknown, rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSettled?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    rateLimiter: AsyncRateLimiter<TFn>,\n  ) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n}\n\nconst defaultOptions: Required<\n  Omit<AsyncRateLimiterOptions<any>, 'limit' | 'window'>\n> = {\n  enabled: true,\n  onError: () => {},\n  onReject: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n}\n\n/**\n * A class that creates an async rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new AsyncRateLimiter(\n *   async (id: string) => await api.getData(id),\n *   { limit: 5, window: 1000 } // 5 calls per second\n * );\n *\n * // Will execute immediately until limit reached, then block\n * await rateLimiter.maybeExecute('123');\n * ```\n */\nexport class AsyncRateLimiter<TFn extends AnyAsyncFunction> {\n  private _options: AsyncRateLimiterOptions<TFn>\n  private _errorCount = 0\n  private _executionTimes: Array<number> = []\n  private _lastResult: ReturnType<TFn> | undefined\n  private _rejectionCount = 0\n  private _settleCount = 0\n  private _successCount = 0\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncRateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncRateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<AsyncRateLimiterOptions<TFn>> {\n    return this._options as Required<AsyncRateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   * If execution is allowed, waits for any previous execution to complete before proceeding.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new AsyncRateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will execute\n   * await rateLimiter.maybeExecute('arg1', 'arg2');\n   *\n   * // Additional calls within the window will be rejected\n   * await rateLimiter.maybeExecute('arg1', 'arg2'); // Rejected\n   * ```\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this.cleanupOldExecutions()\n\n    if (this._executionTimes.length < this._options.limit) {\n      await this.executeFunction(...args)\n      return this._lastResult\n    }\n\n    this.rejectFunction()\n    return undefined\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return\n    const now = Date.now()\n    this._executionTimes.push(now)\n\n    try {\n      this._lastResult = await this.fn(...args)\n      this._successCount++\n      this._options.onSuccess?.(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError?.(error, this)\n    } finally {\n      this._settleCount++\n      this._options.onSettled?.(this)\n    }\n\n    return this._lastResult\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   */\n  getMsUntilNextWindow(): number {\n    return this.getRemainingInWindow() * this._options.window\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has been settled\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._successCount = 0\n    this._errorCount = 0\n    this._rejectionCount = 0\n    this._settleCount = 0\n  }\n}\n\n/**\n * Creates an async rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute\n * const rateLimited = asyncRateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * await rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function asyncRateLimit<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncRateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new AsyncRateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":";;AAwCA,MAAM,iBAEF;AAAA,EACF,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAA;AACnB;AA2BO,MAAM,iBAA+C;AAAA,EAS1D,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AARV,SAAQ,cAAc;AACtB,SAAQ,kBAAiC,CAAC;AAE1C,SAAQ,kBAAkB;AAC1B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AAMtB,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAyD;AAClE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAqD;AACnD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAmBd,MAAM,gBACD,MACmC;AACtC,SAAK,qBAAqB;AAE1B,QAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC/C,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA;AAGd,SAAK,eAAe;AACb,WAAA;AAAA,EAAA;AAAA,EAGT,MAAc,mBACT,MACmC;;AAClC,QAAA,CAAC,KAAK,SAAS,QAAS;AACtB,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA,gBAAgB,KAAK,GAAG;AAEzB,QAAA;AACF,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,uBAAK,UAAS,cAAd,4BAA0B,KAAK,aAAc;AAAA,aACtC,OAAO;AACT,WAAA;AACA,uBAAA,UAAS,YAAT,4BAAmB,OAAO;AAAA,IAAI,UACnC;AACK,WAAA;AACA,uBAAA,UAAS,cAAT,4BAAqB;AAAA,IAAI;AAGhC,WAAO,KAAK;AAAA,EAAA;AAAA,EAGN,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtE,uBAA+B;AAC7B,WAAO,KAAK,qBAAA,IAAyB,KAAK,SAAS;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMrD,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,gBAAgB;AACrB,SAAK,cAAc;AACnB,SAAK,kBAAkB;AACvB,SAAK,eAAe;AAAA,EAAA;AAExB;AAgCgB,SAAA,eACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,iBAAiB,IAAI,cAAc;AACpD,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;;;"}
+{"version":3,"file":"async-rate-limiter.cjs","sources":["../../src/async-rate-limiter.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async rate-limited function\n */\nexport interface AsyncRateLimiterOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Optional error handler for when the rate-limited function throws\n   */\n  onError?: (error: unknown, rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSettled?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    rateLimiter: AsyncRateLimiter<TFn>,\n  ) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n  /**\n   * Type of window to use for rate limiting\n   * - 'fixed': Uses a fixed window that resets after the window period\n   * - 'sliding': Uses a sliding window that allows executions as old ones expire\n   * Defaults to 'fixed'\n   */\n  windowType?: 'fixed' | 'sliding'\n}\n\nconst defaultOptions: Required<\n  Omit<AsyncRateLimiterOptions<any>, 'limit' | 'window'>\n> = {\n  enabled: true,\n  onError: () => {},\n  onReject: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  windowType: 'fixed',\n}\n\n/**\n * A class that creates an async rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * Unlike the non-async RateLimiter, this async version supports returning values from the rate-limited function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the rate-limited function.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new AsyncRateLimiter(\n *   async (id: string) => await api.getData(id),\n *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window\n * );\n *\n * // Will execute immediately until limit reached, then block\n * // Returns the API response directly\n * const data = await rateLimiter.maybeExecute('123');\n * ```\n */\nexport class AsyncRateLimiter<TFn extends AnyAsyncFunction> {\n  private _options: AsyncRateLimiterOptions<TFn>\n  private _errorCount = 0\n  private _executionTimes: Array<number> = []\n  private _lastResult: ReturnType<TFn> | undefined\n  private _rejectionCount = 0\n  private _settleCount = 0\n  private _successCount = 0\n  private _isExecuting = false\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncRateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncRateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<AsyncRateLimiterOptions<TFn>> {\n    return this._options as Required<AsyncRateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   * If execution is allowed, waits for any previous execution to complete before proceeding.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new AsyncRateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will execute\n   * await rateLimiter.maybeExecute('arg1', 'arg2');\n   *\n   * // Additional calls within the window will be rejected\n   * await rateLimiter.maybeExecute('arg1', 'arg2'); // Rejected\n   * ```\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this.cleanupOldExecutions()\n\n    if (this._options.windowType === 'sliding') {\n      // For sliding window, we can execute if we have capacity in the current window\n      if (this._executionTimes.length < this._options.limit) {\n        await this.executeFunction(...args)\n        return this._lastResult\n      }\n    } else {\n      // For fixed window, we need to check if we're in a new window\n      const now = Date.now()\n      const oldestExecution = Math.min(...this._executionTimes)\n      const isNewWindow = oldestExecution + this._options.window <= now\n\n      if (isNewWindow || this._executionTimes.length < this._options.limit) {\n        await this.executeFunction(...args)\n        return this._lastResult\n      }\n    }\n\n    this.rejectFunction()\n    return undefined\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return\n    this._isExecuting = true\n    const now = Date.now()\n    this._executionTimes.push(now)\n\n    try {\n      this._lastResult = await this.fn(...args)\n      this._successCount++\n      this._options.onSuccess?.(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError?.(error, this)\n    } finally {\n      this._isExecuting = false\n      this._settleCount++\n      this._options.onSettled?.(this)\n    }\n\n    return this._lastResult\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   * For fixed windows, this is the time until the current window resets\n   * For sliding windows, this is the time until the oldest execution expires\n   */\n  getMsUntilNextWindow(): number {\n    if (this.getRemainingInWindow() > 0) {\n      return 0\n    }\n    const oldestExecution = Math.min(...this._executionTimes)\n    return oldestExecution + this._options.window - Date.now()\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has been settled\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Returns whether the function is currently executing\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._successCount = 0\n    this._errorCount = 0\n    this._rejectionCount = 0\n    this._settleCount = 0\n  }\n}\n\n/**\n * Creates an async rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Unlike the non-async rate limiter, this async version supports returning values from the rate-limited function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the rate-limited function.\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute with a sliding window\n * const rateLimited = asyncRateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   windowType: 'sliding',\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * // Returns the API response directly\n * const result = await rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function asyncRateLimit<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncRateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new AsyncRateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":";;AA+CA,MAAM,iBAEF;AAAA,EACF,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,YAAY;AACd;AAsCO,MAAM,iBAA+C;AAAA,EAU1D,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AATV,SAAQ,cAAc;AACtB,SAAQ,kBAAiC,CAAC;AAE1C,SAAQ,kBAAkB;AAC1B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,eAAe;AAMrB,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAyD;AAClE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAqD;AACnD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAmBd,MAAM,gBACD,MACmC;AACtC,SAAK,qBAAqB;AAEtB,QAAA,KAAK,SAAS,eAAe,WAAW;AAE1C,UAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC/C,cAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,eAAO,KAAK;AAAA,MAAA;AAAA,IACd,OACK;AAEC,YAAA,MAAM,KAAK,IAAI;AACrB,YAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,YAAM,cAAc,kBAAkB,KAAK,SAAS,UAAU;AAE9D,UAAI,eAAe,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC9D,cAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,eAAO,KAAK;AAAA,MAAA;AAAA,IACd;AAGF,SAAK,eAAe;AACb,WAAA;AAAA,EAAA;AAAA,EAGT,MAAc,mBACT,MACmC;;AAClC,QAAA,CAAC,KAAK,SAAS,QAAS;AAC5B,SAAK,eAAe;AACd,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA,gBAAgB,KAAK,GAAG;AAEzB,QAAA;AACF,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,uBAAK,UAAS,cAAd,4BAA0B,KAAK,aAAc;AAAA,aACtC,OAAO;AACT,WAAA;AACA,uBAAA,UAAS,YAAT,4BAAmB,OAAO;AAAA,IAAI,UACnC;AACA,WAAK,eAAe;AACf,WAAA;AACA,uBAAA,UAAS,cAAT,4BAAqB;AAAA,IAAI;AAGhC,WAAO,KAAK;AAAA,EAAA;AAAA,EAGN,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAQtE,uBAA+B;AACzB,QAAA,KAAK,qBAAqB,IAAI,GAAG;AAC5B,aAAA;AAAA,IAAA;AAET,UAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,WAAO,kBAAkB,KAAK,SAAS,SAAS,KAAK,IAAI;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAM3D,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,gBAAgB;AACrB,SAAK,cAAc;AACnB,SAAK,kBAAkB;AACvB,SAAK,eAAe;AAAA,EAAA;AAExB;AA4CgB,SAAA,eACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,iBAAiB,IAAI,cAAc;AACpD,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;;;"}

dist/cjs/async-rate-limiter.d.cts

@@ -20,2 +20,6 @@ import { AnyAsyncFunction } from './types.cjs';
     /**
+     * Optional callback function that is called when an execution is rejected due to rate limiting
+     */
+    onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void;
+    /**
      * Optional function to call when the rate-limited function is executed
@@ -29,9 +33,12 @@ */
     /**
-     * Optional callback function that is called when an execution is rejected due to rate limiting
+     * Time window in milliseconds within which the limit applies
      */
-    onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void;
+    window: number;
     /**
-     * Time window in milliseconds within which the limit applies
+     * Type of window to use for rate limiting
+     * - 'fixed': Uses a fixed window that resets after the window period
+     * - 'sliding': Uses a sliding window that allows executions as old ones expire
+     * Defaults to 'fixed'
      */
-    window: number;
+    windowType?: 'fixed' | 'sliding';
 }
@@ -45,2 +52,12 @@ /**
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
+ * Unlike the non-async RateLimiter, this async version supports returning values from the rate-limited function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the rate-limited function.
+ *
  * For smoother execution patterns, consider using:
@@ -57,7 +74,8 @@ * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)
  *   async (id: string) => await api.getData(id),
- *   { limit: 5, window: 1000 } // 5 calls per second
+ *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window
  * );
  *
  * // Will execute immediately until limit reached, then block
- * await rateLimiter.maybeExecute('123');
+ * // Returns the API response directly
+ * const data = await rateLimiter.maybeExecute('123');
  * ```
@@ -74,2 +92,3 @@ */
     private _successCount;
+    private _isExecuting;
     constructor(fn: TFn, initialOptions: AsyncRateLimiterOptions<TFn>);
@@ -111,2 +130,4 @@ /**
      * Returns the number of milliseconds until the next execution will be possible
+     * For fixed windows, this is the time until the current window resets
+     * For sliding windows, this is the time until the oldest execution expires
      */
@@ -131,2 +152,6 @@ getMsUntilNextWindow(): number;
     /**
+     * Returns whether the function is currently executing
+     */
+    getIsExecuting(): boolean;
+    /**
      * Resets the rate limiter state
@@ -139,2 +164,12 @@ */
  *
+ * Unlike the non-async rate limiter, this async version supports returning values from the rate-limited function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the rate-limited function.
+ *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:
@@ -150,6 +185,7 @@ * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets
  * ```ts
- * // Rate limit to 5 calls per minute
+ * // Rate limit to 5 calls per minute with a sliding window
  * const rateLimited = asyncRateLimit(makeApiCall, {
  *   limit: 5,
  *   window: 60000,
+ *   windowType: 'sliding',
  *   onReject: (rateLimiter) => {
@@ -162,3 +198,4 @@ *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);
  * // Additional calls will be rejected until the minute window resets
- * await rateLimited();
+ * // Returns the API response directly
+ * const result = await rateLimited();
  *
@@ -165,0 +202,0 @@ * // For more even execution, consider using throttle instead:

dist/cjs/async-throttler.cjs.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"async-throttler.cjs","sources":["../../src/async-throttler.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async throttled function\n */\nexport interface AsyncThrottlerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the throttler is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute the function immediately when called\n   * Defaults to true\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the throttled function throws\n   */\n  onError?: (error: unknown, asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSettled?: (asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    asyncThrottler: AsyncThrottler<TFn>,\n  ) => void\n  /**\n   * Whether to execute the function on the trailing edge of the wait period\n   * Defaults to true\n   */\n  trailing?: boolean\n  /**\n   * Time window in milliseconds during which the function can only be executed once\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncThrottlerOptions<any>> = {\n  enabled: true,\n  leading: true,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async throttled function.\n *\n * Throttling limits how often a function can be executed, allowing only one execution within a specified time window.\n * Unlike debouncing which resets the delay timer on each call, throttling ensures the function executes at a\n * regular interval regardless of how often it's called.\n *\n * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to\n * ensure a maximum execution frequency.\n *\n * @example\n * ```ts\n * const throttler = new AsyncThrottler(async (value: string) => {\n *   await saveToAPI(value);\n * }, { wait: 1000 });\n *\n * // Will only execute once per second no matter how often called\n * inputElement.addEventListener('input', () => {\n *   throttler.maybeExecute(inputElement.value);\n * });\n * ```\n */\nexport class AsyncThrottler<TFn extends AnyAsyncFunction> {\n  private _options: Required<AsyncThrottlerOptions<TFn>>\n  private _abortController: AbortController | null = null\n  private _errorCount = 0\n  private _isExecuting = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastExecutionTime = 0\n  private _lastResult: ReturnType<TFn> | undefined\n  private _nextExecutionTime = 0\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncThrottlerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the throttler options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncThrottlerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this.cancel()\n    }\n  }\n\n  /**\n   * Returns the current options\n   */\n  getOptions(): Required<AsyncThrottlerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the throttled function\n   * If a call is already in progress, it may be blocked or queued depending on the `wait` option\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    const now = Date.now()\n    const timeSinceLastExecution = now - this._lastExecutionTime\n\n    // Handle leading execution\n    if (this._options.leading && timeSinceLastExecution >= this._options.wait) {\n      await this.executeFunction(...args)\n      return this._lastResult\n    } else {\n      // Store the most recent arguments for potential trailing execution\n      this._lastArgs = args\n\n      return new Promise((resolve) => {\n        // Clear any existing timeout to ensure we use the latest arguments\n        if (this._timeoutId) {\n          clearTimeout(this._timeoutId)\n        }\n\n        // Set up trailing execution if enabled\n        if (this._options.trailing) {\n          const _timeSinceLastExecution = this._lastExecutionTime\n            ? now - this._lastExecutionTime\n            : 0\n          const timeoutDuration = this._options.wait - _timeSinceLastExecution\n          this._timeoutId = setTimeout(async () => {\n            if (this._lastArgs !== undefined) {\n              await this.executeFunction(...this._lastArgs)\n            }\n            resolve(this._lastResult)\n          }, timeoutDuration)\n        }\n      })\n    }\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled || this._isExecuting) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._settleCount++\n      this._abortController = null\n      this._lastExecutionTime = Date.now()\n      this._nextExecutionTime = this._lastExecutionTime + this._options.wait\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n  }\n\n  /**\n   * Returns the last execution time\n   */\n  getLastExecutionTime(): number {\n    return this._lastExecutionTime\n  }\n\n  /**\n   * Returns the next execution time\n   */\n  getNextExecutionTime(): number {\n    return this._nextExecutionTime\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the current pending state\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && !!this._timeoutId\n  }\n\n  /**\n   * Returns the current executing state\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async throttled function that limits how often the function can execute.\n * The throttled function will execute at most once per wait period, even if called multiple times.\n * If called while executing, it will wait until execution completes before scheduling the next call.\n *\n * @example\n * ```ts\n * const throttled = asyncThrottle(async () => {\n *   await someAsyncOperation();\n * }, { wait: 1000 });\n *\n * // This will execute at most once per second\n * await throttled();\n * await throttled(); // Waits 1 second before executing\n * ```\n */\nexport function asyncThrottle<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncThrottlerOptions<TFn>, 'enabled'>,\n) {\n  const asyncThrottler = new AsyncThrottler(fn, initialOptions)\n  return asyncThrottler.maybeExecute.bind(asyncThrottler)\n}\n"],"names":[],"mappings":";;AA2CA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AAwBO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAZV,SAAQ,mBAA2C;AACnD,SAAQ,cAAc;AACtB,SAAQ,eAAe;AAEvB,SAAQ,qBAAqB;AAE7B,SAAQ,qBAAqB;AAC7B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,OAAO;AAAA,IAAA;AAAA,EACd;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AAChC,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,yBAAyB,MAAM,KAAK;AAG1C,QAAI,KAAK,SAAS,WAAW,0BAA0B,KAAK,SAAS,MAAM;AACnE,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA,OACP;AAEL,WAAK,YAAY;AAEV,aAAA,IAAI,QAAQ,CAAC,YAAY;AAE9B,YAAI,KAAK,YAAY;AACnB,uBAAa,KAAK,UAAU;AAAA,QAAA;AAI1B,YAAA,KAAK,SAAS,UAAU;AAC1B,gBAAM,0BAA0B,KAAK,qBACjC,MAAM,KAAK,qBACX;AACE,gBAAA,kBAAkB,KAAK,SAAS,OAAO;AACxC,eAAA,aAAa,WAAW,YAAY;AACnC,gBAAA,KAAK,cAAc,QAAW;AAChC,oBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,YAAA;AAE9C,oBAAQ,KAAK,WAAW;AAAA,aACvB,eAAe;AAAA,QAAA;AAAA,MACpB,CACD;AAAA,IAAA;AAAA,EACH;AAAA,EAGF,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,WAAW,KAAK,aAAqB,QAAA;AACnD,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACf,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,qBAAqB,KAAK,IAAI;AACnC,WAAK,qBAAqB,KAAK,qBAAqB,KAAK,SAAS;AAC7D,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,SAAe;AACb,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMnB,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACtB,WAAO,KAAK,SAAS,WAAW,CAAC,CAAC,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMzC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAkBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;;;"}
+{"version":3,"file":"async-throttler.cjs","sources":["../../src/async-throttler.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async throttled function\n */\nexport interface AsyncThrottlerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the throttler is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute the function immediately when called\n   * Defaults to true\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the throttled function throws\n   */\n  onError?: (error: unknown, asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSettled?: (asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    asyncThrottler: AsyncThrottler<TFn>,\n  ) => void\n  /**\n   * Whether to execute the function on the trailing edge of the wait period\n   * Defaults to true\n   */\n  trailing?: boolean\n  /**\n   * Time window in milliseconds during which the function can only be executed once\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncThrottlerOptions<any>> = {\n  enabled: true,\n  leading: true,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async throttled function.\n *\n * Throttling limits how often a function can be executed, allowing only one execution within a specified time window.\n * Unlike debouncing which resets the delay timer on each call, throttling ensures the function executes at a\n * regular interval regardless of how often it's called.\n *\n * Unlike the non-async Throttler, this async version supports returning values from the throttled function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the throttled function.\n *\n * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to\n * ensure a maximum execution frequency.\n *\n * @example\n * ```ts\n * const throttler = new AsyncThrottler(async (value: string) => {\n *   const result = await saveToAPI(value);\n *   return result; // Return value is preserved\n * }, { wait: 1000 });\n *\n * // Will only execute once per second no matter how often called\n * // Returns the API response directly\n * const result = await throttler.maybeExecute(inputElement.value);\n * ```\n */\nexport class AsyncThrottler<TFn extends AnyAsyncFunction> {\n  private _options: Required<AsyncThrottlerOptions<TFn>>\n  private _abortController: AbortController | null = null\n  private _errorCount = 0\n  private _isExecuting = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastExecutionTime = 0\n  private _lastResult: ReturnType<TFn> | undefined\n  private _nextExecutionTime = 0\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncThrottlerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the throttler options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncThrottlerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this.cancel()\n    }\n  }\n\n  /**\n   * Returns the current options\n   */\n  getOptions(): Required<AsyncThrottlerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the throttled function\n   * If a call is already in progress, it may be blocked or queued depending on the `wait` option\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    const now = Date.now()\n    const timeSinceLastExecution = now - this._lastExecutionTime\n\n    // Handle leading execution\n    if (this._options.leading && timeSinceLastExecution >= this._options.wait) {\n      await this.executeFunction(...args)\n      return this._lastResult\n    } else {\n      // Store the most recent arguments for potential trailing execution\n      this._lastArgs = args\n\n      return new Promise((resolve) => {\n        // Clear any existing timeout to ensure we use the latest arguments\n        if (this._timeoutId) {\n          clearTimeout(this._timeoutId)\n        }\n\n        // Set up trailing execution if enabled\n        if (this._options.trailing) {\n          const _timeSinceLastExecution = this._lastExecutionTime\n            ? now - this._lastExecutionTime\n            : 0\n          const timeoutDuration = this._options.wait - _timeSinceLastExecution\n          this._timeoutId = setTimeout(async () => {\n            if (this._lastArgs !== undefined) {\n              await this.executeFunction(...this._lastArgs)\n            }\n            resolve(this._lastResult)\n          }, timeoutDuration)\n        }\n      })\n    }\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled || this._isExecuting) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._settleCount++\n      this._abortController = null\n      this._lastExecutionTime = Date.now()\n      this._nextExecutionTime = this._lastExecutionTime + this._options.wait\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n  }\n\n  /**\n   * Returns the last execution time\n   */\n  getLastExecutionTime(): number {\n    return this._lastExecutionTime\n  }\n\n  /**\n   * Returns the next execution time\n   */\n  getNextExecutionTime(): number {\n    return this._nextExecutionTime\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the current pending state\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && !!this._timeoutId\n  }\n\n  /**\n   * Returns the current executing state\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async throttled function that limits how often the function can execute.\n * The throttled function will execute at most once per wait period, even if called multiple times.\n * If called while executing, it will wait until execution completes before scheduling the next call.\n *\n * Unlike the non-async Throttler, this async version supports returning values from the throttled function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the throttled function.\n *\n * @example\n * ```ts\n * const throttled = asyncThrottle(async (value: string) => {\n *   const result = await saveToAPI(value);\n *   return result; // Return value is preserved\n * }, { wait: 1000 });\n *\n * // This will execute at most once per second\n * // Returns the API response directly\n * const result = await throttled(inputElement.value);\n * ```\n */\nexport function asyncThrottle<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncThrottlerOptions<TFn>, 'enabled'>,\n) {\n  const asyncThrottler = new AsyncThrottler(fn, initialOptions)\n  return asyncThrottler.maybeExecute.bind(asyncThrottler)\n}\n"],"names":[],"mappings":";;AA2CA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AA4BO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAZV,SAAQ,mBAA2C;AACnD,SAAQ,cAAc;AACtB,SAAQ,eAAe;AAEvB,SAAQ,qBAAqB;AAE7B,SAAQ,qBAAqB;AAC7B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,OAAO;AAAA,IAAA;AAAA,EACd;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AAChC,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,yBAAyB,MAAM,KAAK;AAG1C,QAAI,KAAK,SAAS,WAAW,0BAA0B,KAAK,SAAS,MAAM;AACnE,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA,OACP;AAEL,WAAK,YAAY;AAEV,aAAA,IAAI,QAAQ,CAAC,YAAY;AAE9B,YAAI,KAAK,YAAY;AACnB,uBAAa,KAAK,UAAU;AAAA,QAAA;AAI1B,YAAA,KAAK,SAAS,UAAU;AAC1B,gBAAM,0BAA0B,KAAK,qBACjC,MAAM,KAAK,qBACX;AACE,gBAAA,kBAAkB,KAAK,SAAS,OAAO;AACxC,eAAA,aAAa,WAAW,YAAY;AACnC,gBAAA,KAAK,cAAc,QAAW;AAChC,oBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,YAAA;AAE9C,oBAAQ,KAAK,WAAW;AAAA,aACvB,eAAe;AAAA,QAAA;AAAA,MACpB,CACD;AAAA,IAAA;AAAA,EACH;AAAA,EAGF,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,WAAW,KAAK,aAAqB,QAAA;AACnD,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACf,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,qBAAqB,KAAK,IAAI;AACnC,WAAK,qBAAqB,KAAK,qBAAqB,KAAK,SAAS;AAC7D,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,SAAe;AACb,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMnB,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACtB,WAAO,KAAK,SAAS,WAAW,CAAC,CAAC,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMzC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAuBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;;;"}

dist/cjs/async-throttler.d.cts

@@ -46,2 +46,6 @@ import { AnyAsyncFunction } from './types.cjs';
  *
+ * Unlike the non-async Throttler, this async version supports returning values from the throttled function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the throttled function.
+ *
  * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to
@@ -53,9 +57,9 @@ * ensure a maximum execution frequency.
  * const throttler = new AsyncThrottler(async (value: string) => {
- *   await saveToAPI(value);
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // Will only execute once per second no matter how often called
- * inputElement.addEventListener('input', () => {
- *   throttler.maybeExecute(inputElement.value);
- * });
+ * // Returns the API response directly
+ * const result = await throttler.maybeExecute(inputElement.value);
  * ```
@@ -134,13 +138,18 @@ */
  *
+ * Unlike the non-async Throttler, this async version supports returning values from the throttled function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the throttled function.
+ *
  * @example
  * ```ts
- * const throttled = asyncThrottle(async () => {
- *   await someAsyncOperation();
+ * const throttled = asyncThrottle(async (value: string) => {
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // This will execute at most once per second
- * await throttled();
- * await throttled(); // Waits 1 second before executing
+ * // Returns the API response directly
+ * const result = await throttled(inputElement.value);
  * ```
  */
 export declare function asyncThrottle<TFn extends AnyAsyncFunction>(fn: TFn, initialOptions: Omit<AsyncThrottlerOptions<TFn>, 'enabled'>): (...args: Parameters<TFn>) => Promise<ReturnType<TFn> | undefined>;

dist/cjs/rate-limiter.cjs

@@ -10,3 +10,4 @@ "use strict";
   },
-  window: 0
+  window: 0,
+  windowType: "fixed"
 };
@@ -54,5 +55,15 @@ class RateLimiter {
     this.cleanupOldExecutions();
-    if (this._executionTimes.length < this._options.limit) {
-      this.executeFunction(...args);
-      return true;
+    if (this._options.windowType === "sliding") {
+      if (this._executionTimes.length < this._options.limit) {
+        this.executeFunction(...args);
+        return true;
+      }
+    } else {
+      const now = Date.now();
+      const oldestExecution = Math.min(...this._executionTimes);
+      const isNewWindow = oldestExecution + this._options.window <= now;
+      if (isNewWindow || this._executionTimes.length < this._options.limit) {
+        this.executeFunction(...args);
+        return true;
+      }
     }
@@ -107,2 +118,5 @@ this.rejectFunction();
   getMsUntilNextWindow() {
+    if (this.getRemainingInWindow() > 0) {
+      return 0;
+    }
     const oldestExecution = Math.min(...this._executionTimes);
@@ -109,0 +123,0 @@ return oldestExecution + this._options.window - Date.now();

dist/cjs/rate-limiter.cjs.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"rate-limiter.cjs","sources":["../../src/rate-limiter.ts"],"sourcesContent":["import type { AnyFunction } from './types'\n\n/**\n * Options for configuring a rate-limited function\n */\nexport interface RateLimiterOptions<TFn extends AnyFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Callback function that is called after the function is executed\n   */\n  onExecute?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n}\n\nconst defaultOptions: Required<RateLimiterOptions<any>> = {\n  enabled: true,\n  limit: 1,\n  onExecute: () => {},\n  onReject: () => {},\n  window: 0,\n}\n\n/**\n * A class that creates a rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new RateLimiter(\n *   (id: string) => api.getData(id),\n *   { limit: 5, window: 1000 } // 5 calls per second\n * );\n *\n * // Will execute immediately until limit reached, then block\n * rateLimiter.maybeExecute('123');\n * ```\n */\nexport class RateLimiter<TFn extends AnyFunction> {\n  private _executionCount = 0\n  private _rejectionCount = 0\n  private _executionTimes: Array<number> = []\n  private _options: RateLimiterOptions<TFn>\n\n  constructor(\n    private fn: TFn,\n    initialOptions: RateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<RateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<RateLimiterOptions<TFn>> {\n    return this._options as Required<RateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new RateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will return true\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // true\n   *\n   * // Additional calls within the window will return false\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // false\n   * ```\n   */\n  maybeExecute(...args: Parameters<TFn>): boolean {\n    this.cleanupOldExecutions()\n\n    if (this._executionTimes.length < this._options.limit) {\n      this.executeFunction(...args)\n      return true\n    }\n\n    this.rejectFunction()\n\n    return false\n  }\n\n  private executeFunction(...args: Parameters<TFn>): void {\n    if (!this._options.enabled) return\n    const now = Date.now()\n    this._executionCount++\n    this._executionTimes.push(now)\n    this.fn(...args) // execute the function\n    this._options.onExecute?.(this)\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getExecutionCount(): number {\n    return this._executionCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   */\n  getMsUntilNextWindow(): number {\n    const oldestExecution = Math.min(...this._executionTimes)\n    return oldestExecution + this._options.window - Date.now()\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._executionCount = 0\n    this._rejectionCount = 0\n  }\n}\n\n/**\n * Creates a rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute\n * const rateLimited = rateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function rateLimit<TFn extends AnyFunction>(\n  fn: TFn,\n  initialOptions: Omit<RateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new RateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":";;AA6BA,MAAM,iBAAoD;AAAA,EACxD,SAAS;AAAA,EACT,OAAO;AAAA,EACP,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,QAAQ;AACV;AA2BO,MAAM,YAAqC;AAAA,EAMhD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AANV,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAiC,CAAC;AAOxC,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAoD;AAC7D,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAgD;AAC9C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAkBd,gBAAgB,MAAgC;AAC9C,SAAK,qBAAqB;AAE1B,QAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAChD,WAAA,gBAAgB,GAAG,IAAI;AACrB,aAAA;AAAA,IAAA;AAGT,SAAK,eAAe;AAEb,WAAA;AAAA,EAAA;AAAA,EAGD,mBAAmB,MAA6B;;AAClD,QAAA,CAAC,KAAK,SAAS,QAAS;AACtB,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA;AACA,SAAA,gBAAgB,KAAK,GAAG;AACxB,SAAA,GAAG,GAAG,IAAI;AACV,qBAAA,UAAS,cAAT,4BAAqB;AAAA,EAAI;AAAA,EAGxB,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtE,uBAA+B;AAC7B,UAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,WAAO,kBAAkB,KAAK,SAAS,SAAS,KAAK,IAAI;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAM3D,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,kBAAkB;AACvB,SAAK,kBAAkB;AAAA,EAAA;AAE3B;AAgCgB,SAAA,UACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,YAAY,IAAI,cAAc;AAC/C,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;;;"}
+{"version":3,"file":"rate-limiter.cjs","sources":["../../src/rate-limiter.ts"],"sourcesContent":["import type { AnyFunction } from './types'\n\n/**\n * Options for configuring a rate-limited function\n */\nexport interface RateLimiterOptions<TFn extends AnyFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Callback function that is called after the function is executed\n   */\n  onExecute?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n  /**\n   * Type of window to use for rate limiting\n   * - 'fixed': Uses a fixed window that resets after the window period\n   * - 'sliding': Uses a sliding window that allows executions as old ones expire\n   * Defaults to 'fixed'\n   */\n  windowType?: 'fixed' | 'sliding'\n}\n\nconst defaultOptions: Required<RateLimiterOptions<any>> = {\n  enabled: true,\n  limit: 1,\n  onExecute: () => {},\n  onReject: () => {},\n  window: 0,\n  windowType: 'fixed',\n}\n\n/**\n * A class that creates a rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new RateLimiter(\n *   (id: string) => api.getData(id),\n *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window\n * );\n *\n * // Will execute immediately until limit reached, then block\n * rateLimiter.maybeExecute('123');\n * ```\n */\nexport class RateLimiter<TFn extends AnyFunction> {\n  private _executionCount = 0\n  private _rejectionCount = 0\n  private _executionTimes: Array<number> = []\n  private _options: RateLimiterOptions<TFn>\n\n  constructor(\n    private fn: TFn,\n    initialOptions: RateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<RateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<RateLimiterOptions<TFn>> {\n    return this._options as Required<RateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new RateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will return true\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // true\n   *\n   * // Additional calls within the window will return false\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // false\n   * ```\n   */\n  maybeExecute(...args: Parameters<TFn>): boolean {\n    this.cleanupOldExecutions()\n\n    if (this._options.windowType === 'sliding') {\n      // For sliding window, we can execute if we have capacity in the current window\n      if (this._executionTimes.length < this._options.limit) {\n        this.executeFunction(...args)\n        return true\n      }\n    } else {\n      // For fixed window, we need to check if we're in a new window\n      const now = Date.now()\n      const oldestExecution = Math.min(...this._executionTimes)\n      const isNewWindow = oldestExecution + this._options.window <= now\n\n      if (isNewWindow || this._executionTimes.length < this._options.limit) {\n        this.executeFunction(...args)\n        return true\n      }\n    }\n\n    this.rejectFunction()\n    return false\n  }\n\n  private executeFunction(...args: Parameters<TFn>): void {\n    if (!this._options.enabled) return\n    const now = Date.now()\n    this._executionCount++\n    this._executionTimes.push(now)\n    this.fn(...args) // execute the function\n    this._options.onExecute?.(this)\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getExecutionCount(): number {\n    return this._executionCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   */\n  getMsUntilNextWindow(): number {\n    if (this.getRemainingInWindow() > 0) {\n      return 0\n    }\n    const oldestExecution = Math.min(...this._executionTimes)\n    return oldestExecution + this._options.window - Date.now()\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._executionCount = 0\n    this._rejectionCount = 0\n  }\n}\n\n/**\n * Creates a rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute with a sliding window\n * const rateLimited = rateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   windowType: 'sliding',\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function rateLimit<TFn extends AnyFunction>(\n  fn: TFn,\n  initialOptions: Omit<RateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new RateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":";;AAoCA,MAAM,iBAAoD;AAAA,EACxD,SAAS;AAAA,EACT,OAAO;AAAA,EACP,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,QAAQ;AAAA,EACR,YAAY;AACd;AAiCO,MAAM,YAAqC;AAAA,EAMhD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AANV,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAiC,CAAC;AAOxC,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAoD;AAC7D,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAgD;AAC9C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAkBd,gBAAgB,MAAgC;AAC9C,SAAK,qBAAqB;AAEtB,QAAA,KAAK,SAAS,eAAe,WAAW;AAE1C,UAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAChD,aAAA,gBAAgB,GAAG,IAAI;AACrB,eAAA;AAAA,MAAA;AAAA,IACT,OACK;AAEC,YAAA,MAAM,KAAK,IAAI;AACrB,YAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,YAAM,cAAc,kBAAkB,KAAK,SAAS,UAAU;AAE9D,UAAI,eAAe,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC/D,aAAA,gBAAgB,GAAG,IAAI;AACrB,eAAA;AAAA,MAAA;AAAA,IACT;AAGF,SAAK,eAAe;AACb,WAAA;AAAA,EAAA;AAAA,EAGD,mBAAmB,MAA6B;;AAClD,QAAA,CAAC,KAAK,SAAS,QAAS;AACtB,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA;AACA,SAAA,gBAAgB,KAAK,GAAG;AACxB,SAAA,GAAG,GAAG,IAAI;AACV,qBAAA,UAAS,cAAT,4BAAqB;AAAA,EAAI;AAAA,EAGxB,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtE,uBAA+B;AACzB,QAAA,KAAK,qBAAqB,IAAI,GAAG;AAC5B,aAAA;AAAA,IAAA;AAET,UAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,WAAO,kBAAkB,KAAK,SAAS,SAAS,KAAK,IAAI;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAM3D,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,kBAAkB;AACvB,SAAK,kBAAkB;AAAA,EAAA;AAE3B;AAuCgB,SAAA,UACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,YAAY,IAAI,cAAc;AAC/C,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;;;"}

dist/cjs/rate-limiter.d.cts

@@ -27,2 +27,9 @@ import { AnyFunction } from './types.cjs';
     window: number;
+    /**
+     * Type of window to use for rate limiting
+     * - 'fixed': Uses a fixed window that resets after the window period
+     * - 'sliding': Uses a sliding window that allows executions as old ones expire
+     * Defaults to 'fixed'
+     */
+    windowType?: 'fixed' | 'sliding';
 }
@@ -36,2 +43,8 @@ /**
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * For smoother execution patterns, consider using:
@@ -48,3 +61,3 @@ * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)
  *   (id: string) => api.getData(id),
- *   { limit: 5, window: 1000 } // 5 calls per second
+ *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window
  * );
@@ -120,2 +133,8 @@ *
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically
@@ -126,6 +145,7 @@ * need to enforce a hard limit on the number of executions within a time period.
  * ```ts
- * // Rate limit to 5 calls per minute
+ * // Rate limit to 5 calls per minute with a sliding window
  * const rateLimited = rateLimit(makeApiCall, {
  *   limit: 5,
  *   window: 60000,
+ *   windowType: 'sliding',
  *   onReject: (rateLimiter) => {
@@ -132,0 +152,0 @@ *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);

dist/esm/async-debouncer.d.ts

@@ -49,12 +49,16 @@ import { AnyAsyncFunction } from './types.js';
  *
+ * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the debounced function.
+ *
  * @example
  * ```ts
  * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {
- *   await searchAPI(value);
+ *   const results = await searchAPI(value);
+ *   return results; // Return value is preserved
  * }, { wait: 500 });
  *
  * // Called on each keystroke but only executes after 500ms of no typing
- * inputElement.addEventListener('input', () => {
- *   asyncDebouncer.maybeExecute(inputElement.value);
- * });
+ * // Returns the API response directly
+ * const results = await asyncDebouncer.maybeExecute(inputElement.value);
  * ```
@@ -129,14 +133,18 @@ */
  *
+ * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the debounced function.
+ *
  * @example
  * ```ts
  * const debounced = asyncDebounce(async (value: string) => {
- *   await saveToAPI(value);
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // Will only execute once, 1 second after the last call
- * await debounced("first");  // Cancelled
- * await debounced("second"); // Cancelled
- * await debounced("third");  // Executes after 1s
+ * // Returns the API response directly
+ * const result = await debounced("third");
  * ```
  */
 export declare function asyncDebounce<TFn extends AnyAsyncFunction>(fn: TFn, initialOptions: Omit<AsyncDebouncerOptions<TFn>, 'enabled'>): (...args: Parameters<TFn>) => Promise<ReturnType<TFn> | undefined>;

dist/esm/async-debouncer.js.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"async-debouncer.js","sources":["../../src/async-debouncer.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async debounced function\n */\nexport interface AsyncDebouncerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the debouncer is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute on the leading edge of the timeout.\n   * Defaults to false.\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the debounced function throws\n   */\n  onError?: (error: unknown, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSettled?: (debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSuccess?: (result: ReturnType<TFn>, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Whether to execute on the trailing edge of the timeout.\n   * Defaults to true.\n   */\n  trailing?: boolean\n  /**\n   * Delay in milliseconds to wait after the last call before executing\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncDebouncerOptions<any>> = {\n  enabled: true,\n  leading: false,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async debounced function.\n *\n * Debouncing ensures that a function is only executed after a specified delay has passed since its last invocation.\n * Each new invocation resets the delay timer. This is useful for handling frequent events like window resizing\n * or input changes where you only want to execute the handler after the events have stopped occurring.\n *\n * Unlike throttling which allows execution at regular intervals, debouncing prevents any execution until\n * the function stops being called for the specified delay period.\n *\n * @example\n * ```ts\n * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {\n *   await searchAPI(value);\n * }, { wait: 500 });\n *\n * // Called on each keystroke but only executes after 500ms of no typing\n * inputElement.addEventListener('input', () => {\n *   asyncDebouncer.maybeExecute(inputElement.value);\n * });\n * ```\n */\nexport class AsyncDebouncer<TFn extends AnyAsyncFunction> {\n  private _abortController: AbortController | null = null\n  private _canLeadingExecute = true\n  private _errorCount = 0\n  private _isExecuting = false\n  private _isPending = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastResult: ReturnType<TFn> | undefined\n  private _options: Required<AsyncDebouncerOptions<TFn>>\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncDebouncerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the debouncer options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncDebouncerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this._isPending = false\n    }\n  }\n\n  /**\n   * Returns the current debouncer options\n   */\n  getOptions(): Required<AsyncDebouncerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the debounced function\n   * If a call is already in progress, it will be queued\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this._cancel()\n    this._lastArgs = args\n\n    // Handle leading execution\n    if (this._options.leading && this._canLeadingExecute) {\n      this._canLeadingExecute = false\n      await this.executeFunction(...args)\n      return this._lastResult\n    }\n\n    // Handle trailing execution\n    if (this._options.trailing) {\n      this._isPending = true\n    }\n\n    return new Promise((resolve) => {\n      this._timeoutId = setTimeout(async () => {\n        // Execute trailing if enabled\n        if (this._options.trailing && this._lastArgs) {\n          await this.executeFunction(...this._lastArgs)\n        }\n\n        // Reset state and resolve\n        this._canLeadingExecute = true\n        resolve(this._lastResult)\n      }, this._options.wait)\n    })\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._isPending = false\n      this._settleCount++\n      this._abortController = null\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancel without resetting _canLeadingExecute\n   */\n  private _cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n    this._isPending = false\n    this._isExecuting = false\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    this._canLeadingExecute = true\n    this._cancel()\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns `true` if there is a pending execution queued up for trailing execution\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && this._isPending\n  }\n\n  /**\n   * Returns `true` if there is currently an execution in progress\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async debounced function that delays execution until after a specified wait time.\n * The debounced function will only execute once the wait period has elapsed without any new calls.\n * If called again during the wait period, the timer resets and a new wait period begins.\n *\n * @example\n * ```ts\n * const debounced = asyncDebounce(async (value: string) => {\n *   await saveToAPI(value);\n * }, { wait: 1000 });\n *\n * // Will only execute once, 1 second after the last call\n * await debounced(\"first\");  // Cancelled\n * await debounced(\"second\"); // Cancelled\n * await debounced(\"third\");  // Executes after 1s\n * ```\n */\nexport function asyncDebounce<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncDebouncerOptions<TFn>, 'enabled'>,\n) {\n  const asyncDebouncer = new AsyncDebouncer(fn, initialOptions)\n  return asyncDebouncer.maybeExecute.bind(asyncDebouncer)\n}\n"],"names":[],"mappings":"AAwCA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AAwBO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAbV,SAAQ,mBAA2C;AACnD,SAAQ,qBAAqB;AAC7B,SAAQ,cAAc;AACtB,SAAQ,eAAe;AACvB,SAAQ,aAAa;AAIrB,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,aAAa;AAAA,IAAA;AAAA,EACpB;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AACtC,SAAK,QAAQ;AACb,SAAK,YAAY;AAGjB,QAAI,KAAK,SAAS,WAAW,KAAK,oBAAoB;AACpD,WAAK,qBAAqB;AACpB,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA;AAIV,QAAA,KAAK,SAAS,UAAU;AAC1B,WAAK,aAAa;AAAA,IAAA;AAGb,WAAA,IAAI,QAAQ,CAAC,YAAY;AACzB,WAAA,aAAa,WAAW,YAAY;AAEvC,YAAI,KAAK,SAAS,YAAY,KAAK,WAAW;AAC5C,gBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,QAAA;AAI9C,aAAK,qBAAqB;AAC1B,gBAAQ,KAAK,WAAW;AAAA,MAAA,GACvB,KAAK,SAAS,IAAI;AAAA,IAAA,CACtB;AAAA,EAAA;AAAA,EAGH,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,QAAgB,QAAA;AAC9B,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACpB,WAAK,aAAa;AACb,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMN,UAAgB;AACtB,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AACjB,SAAK,aAAa;AAClB,SAAK,eAAe;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtB,SAAe;AACb,SAAK,qBAAqB;AAC1B,SAAK,QAAQ;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMf,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACf,WAAA,KAAK,SAAS,WAAW,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMvC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAmBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;"}
+{"version":3,"file":"async-debouncer.js","sources":["../../src/async-debouncer.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async debounced function\n */\nexport interface AsyncDebouncerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the debouncer is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute on the leading edge of the timeout.\n   * Defaults to false.\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the debounced function throws\n   */\n  onError?: (error: unknown, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSettled?: (debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Optional callback to call when the debounced function is executed\n   */\n  onSuccess?: (result: ReturnType<TFn>, debouncer: AsyncDebouncer<TFn>) => void\n  /**\n   * Whether to execute on the trailing edge of the timeout.\n   * Defaults to true.\n   */\n  trailing?: boolean\n  /**\n   * Delay in milliseconds to wait after the last call before executing\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncDebouncerOptions<any>> = {\n  enabled: true,\n  leading: false,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async debounced function.\n *\n * Debouncing ensures that a function is only executed after a specified delay has passed since its last invocation.\n * Each new invocation resets the delay timer. This is useful for handling frequent events like window resizing\n * or input changes where you only want to execute the handler after the events have stopped occurring.\n *\n * Unlike throttling which allows execution at regular intervals, debouncing prevents any execution until\n * the function stops being called for the specified delay period.\n *\n * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the debounced function.\n *\n * @example\n * ```ts\n * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {\n *   const results = await searchAPI(value);\n *   return results; // Return value is preserved\n * }, { wait: 500 });\n *\n * // Called on each keystroke but only executes after 500ms of no typing\n * // Returns the API response directly\n * const results = await asyncDebouncer.maybeExecute(inputElement.value);\n * ```\n */\nexport class AsyncDebouncer<TFn extends AnyAsyncFunction> {\n  private _abortController: AbortController | null = null\n  private _canLeadingExecute = true\n  private _errorCount = 0\n  private _isExecuting = false\n  private _isPending = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastResult: ReturnType<TFn> | undefined\n  private _options: Required<AsyncDebouncerOptions<TFn>>\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncDebouncerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the debouncer options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncDebouncerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this._isPending = false\n    }\n  }\n\n  /**\n   * Returns the current debouncer options\n   */\n  getOptions(): Required<AsyncDebouncerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the debounced function\n   * If a call is already in progress, it will be queued\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this._cancel()\n    this._lastArgs = args\n\n    // Handle leading execution\n    if (this._options.leading && this._canLeadingExecute) {\n      this._canLeadingExecute = false\n      await this.executeFunction(...args)\n      return this._lastResult\n    }\n\n    // Handle trailing execution\n    if (this._options.trailing) {\n      this._isPending = true\n    }\n\n    return new Promise((resolve) => {\n      this._timeoutId = setTimeout(async () => {\n        // Execute trailing if enabled\n        if (this._options.trailing && this._lastArgs) {\n          await this.executeFunction(...this._lastArgs)\n        }\n\n        // Reset state and resolve\n        this._canLeadingExecute = true\n        resolve(this._lastResult)\n      }, this._options.wait)\n    })\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._isPending = false\n      this._settleCount++\n      this._abortController = null\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancel without resetting _canLeadingExecute\n   */\n  private _cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n    this._isPending = false\n    this._isExecuting = false\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    this._canLeadingExecute = true\n    this._cancel()\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns `true` if there is a pending execution queued up for trailing execution\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && this._isPending\n  }\n\n  /**\n   * Returns `true` if there is currently an execution in progress\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async debounced function that delays execution until after a specified wait time.\n * The debounced function will only execute once the wait period has elapsed without any new calls.\n * If called again during the wait period, the timer resets and a new wait period begins.\n *\n * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the debounced function.\n *\n * @example\n * ```ts\n * const debounced = asyncDebounce(async (value: string) => {\n *   const result = await saveToAPI(value);\n *   return result; // Return value is preserved\n * }, { wait: 1000 });\n *\n * // Will only execute once, 1 second after the last call\n * // Returns the API response directly\n * const result = await debounced(\"third\");\n * ```\n */\nexport function asyncDebounce<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncDebouncerOptions<TFn>, 'enabled'>,\n) {\n  const asyncDebouncer = new AsyncDebouncer(fn, initialOptions)\n  return asyncDebouncer.maybeExecute.bind(asyncDebouncer)\n}\n"],"names":[],"mappings":"AAwCA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AA4BO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAbV,SAAQ,mBAA2C;AACnD,SAAQ,qBAAqB;AAC7B,SAAQ,cAAc;AACtB,SAAQ,eAAe;AACvB,SAAQ,aAAa;AAIrB,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,aAAa;AAAA,IAAA;AAAA,EACpB;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AACtC,SAAK,QAAQ;AACb,SAAK,YAAY;AAGjB,QAAI,KAAK,SAAS,WAAW,KAAK,oBAAoB;AACpD,WAAK,qBAAqB;AACpB,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA;AAIV,QAAA,KAAK,SAAS,UAAU;AAC1B,WAAK,aAAa;AAAA,IAAA;AAGb,WAAA,IAAI,QAAQ,CAAC,YAAY;AACzB,WAAA,aAAa,WAAW,YAAY;AAEvC,YAAI,KAAK,SAAS,YAAY,KAAK,WAAW;AAC5C,gBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,QAAA;AAI9C,aAAK,qBAAqB;AAC1B,gBAAQ,KAAK,WAAW;AAAA,MAAA,GACvB,KAAK,SAAS,IAAI;AAAA,IAAA,CACtB;AAAA,EAAA;AAAA,EAGH,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,QAAgB,QAAA;AAC9B,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACpB,WAAK,aAAa;AACb,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMN,UAAgB;AACtB,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AACjB,SAAK,aAAa;AAClB,SAAK,eAAe;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtB,SAAe;AACb,SAAK,qBAAqB;AAC1B,SAAK,QAAQ;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMf,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACf,WAAA,KAAK,SAAS,WAAW,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMvC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAuBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;"}

dist/esm/async-rate-limiter.d.ts

@@ -20,2 +20,6 @@ import { AnyAsyncFunction } from './types.js';
     /**
+     * Optional callback function that is called when an execution is rejected due to rate limiting
+     */
+    onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void;
+    /**
      * Optional function to call when the rate-limited function is executed
@@ -29,9 +33,12 @@ */
     /**
-     * Optional callback function that is called when an execution is rejected due to rate limiting
+     * Time window in milliseconds within which the limit applies
      */
-    onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void;
+    window: number;
     /**
-     * Time window in milliseconds within which the limit applies
+     * Type of window to use for rate limiting
+     * - 'fixed': Uses a fixed window that resets after the window period
+     * - 'sliding': Uses a sliding window that allows executions as old ones expire
+     * Defaults to 'fixed'
      */
-    window: number;
+    windowType?: 'fixed' | 'sliding';
 }
@@ -45,2 +52,12 @@ /**
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
+ * Unlike the non-async RateLimiter, this async version supports returning values from the rate-limited function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the rate-limited function.
+ *
  * For smoother execution patterns, consider using:
@@ -57,7 +74,8 @@ * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)
  *   async (id: string) => await api.getData(id),
- *   { limit: 5, window: 1000 } // 5 calls per second
+ *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window
  * );
  *
  * // Will execute immediately until limit reached, then block
- * await rateLimiter.maybeExecute('123');
+ * // Returns the API response directly
+ * const data = await rateLimiter.maybeExecute('123');
  * ```
@@ -74,2 +92,3 @@ */
     private _successCount;
+    private _isExecuting;
     constructor(fn: TFn, initialOptions: AsyncRateLimiterOptions<TFn>);
@@ -111,2 +130,4 @@ /**
      * Returns the number of milliseconds until the next execution will be possible
+     * For fixed windows, this is the time until the current window resets
+     * For sliding windows, this is the time until the oldest execution expires
      */
@@ -131,2 +152,6 @@ getMsUntilNextWindow(): number;
     /**
+     * Returns whether the function is currently executing
+     */
+    getIsExecuting(): boolean;
+    /**
      * Resets the rate limiter state
@@ -139,2 +164,12 @@ */
  *
+ * Unlike the non-async rate limiter, this async version supports returning values from the rate-limited function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the rate-limited function.
+ *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:
@@ -150,6 +185,7 @@ * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets
  * ```ts
- * // Rate limit to 5 calls per minute
+ * // Rate limit to 5 calls per minute with a sliding window
  * const rateLimited = asyncRateLimit(makeApiCall, {
  *   limit: 5,
  *   window: 60000,
+ *   windowType: 'sliding',
  *   onReject: (rateLimiter) => {
@@ -162,3 +198,4 @@ *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);
  * // Additional calls will be rejected until the minute window resets
- * await rateLimited();
+ * // Returns the API response directly
+ * const result = await rateLimited();
  *
@@ -165,0 +202,0 @@ * // For more even execution, consider using throttle instead:

dist/esm/async-rate-limiter.js

@@ -10,3 +10,4 @@ const defaultOptions = {
   onSuccess: () => {
-  }
+  },
+  windowType: "fixed"
 };
@@ -21,2 +22,3 @@ class AsyncRateLimiter {
     this._successCount = 0;
+    this._isExecuting = false;
     this._options = {
@@ -58,5 +60,15 @@ ...defaultOptions,
     this.cleanupOldExecutions();
-    if (this._executionTimes.length < this._options.limit) {
-      await this.executeFunction(...args);
-      return this._lastResult;
+    if (this._options.windowType === "sliding") {
+      if (this._executionTimes.length < this._options.limit) {
+        await this.executeFunction(...args);
+        return this._lastResult;
+      }
+    } else {
+      const now = Date.now();
+      const oldestExecution = Math.min(...this._executionTimes);
+      const isNewWindow = oldestExecution + this._options.window <= now;
+      if (isNewWindow || this._executionTimes.length < this._options.limit) {
+        await this.executeFunction(...args);
+        return this._lastResult;
+      }
     }
@@ -69,2 +81,3 @@ this.rejectFunction();
     if (!this._options.enabled) return;
+    this._isExecuting = true;
     const now = Date.now();
@@ -80,2 +93,3 @@ this._executionTimes.push(now);
     } finally {
+      this._isExecuting = false;
       this._settleCount++;
@@ -108,5 +122,11 @@ (_f = (_e = this._options).onSettled) == null ? void 0 : _f.call(_e, this);
    * Returns the number of milliseconds until the next execution will be possible
+   * For fixed windows, this is the time until the current window resets
+   * For sliding windows, this is the time until the oldest execution expires
    */
   getMsUntilNextWindow() {
-    return this.getRemainingInWindow() * this._options.window;
+    if (this.getRemainingInWindow() > 0) {
+      return 0;
+    }
+    const oldestExecution = Math.min(...this._executionTimes);
+    return oldestExecution + this._options.window - Date.now();
   }
@@ -138,2 +158,8 @@ /**
   /**
+   * Returns whether the function is currently executing
+   */
+  getIsExecuting() {
+    return this._isExecuting;
+  }
+  /**
    * Resets the rate limiter state
@@ -140,0 +166,0 @@ */

dist/esm/async-rate-limiter.js.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"async-rate-limiter.js","sources":["../../src/async-rate-limiter.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async rate-limited function\n */\nexport interface AsyncRateLimiterOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Optional error handler for when the rate-limited function throws\n   */\n  onError?: (error: unknown, rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSettled?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    rateLimiter: AsyncRateLimiter<TFn>,\n  ) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n}\n\nconst defaultOptions: Required<\n  Omit<AsyncRateLimiterOptions<any>, 'limit' | 'window'>\n> = {\n  enabled: true,\n  onError: () => {},\n  onReject: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n}\n\n/**\n * A class that creates an async rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new AsyncRateLimiter(\n *   async (id: string) => await api.getData(id),\n *   { limit: 5, window: 1000 } // 5 calls per second\n * );\n *\n * // Will execute immediately until limit reached, then block\n * await rateLimiter.maybeExecute('123');\n * ```\n */\nexport class AsyncRateLimiter<TFn extends AnyAsyncFunction> {\n  private _options: AsyncRateLimiterOptions<TFn>\n  private _errorCount = 0\n  private _executionTimes: Array<number> = []\n  private _lastResult: ReturnType<TFn> | undefined\n  private _rejectionCount = 0\n  private _settleCount = 0\n  private _successCount = 0\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncRateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncRateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<AsyncRateLimiterOptions<TFn>> {\n    return this._options as Required<AsyncRateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   * If execution is allowed, waits for any previous execution to complete before proceeding.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new AsyncRateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will execute\n   * await rateLimiter.maybeExecute('arg1', 'arg2');\n   *\n   * // Additional calls within the window will be rejected\n   * await rateLimiter.maybeExecute('arg1', 'arg2'); // Rejected\n   * ```\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this.cleanupOldExecutions()\n\n    if (this._executionTimes.length < this._options.limit) {\n      await this.executeFunction(...args)\n      return this._lastResult\n    }\n\n    this.rejectFunction()\n    return undefined\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return\n    const now = Date.now()\n    this._executionTimes.push(now)\n\n    try {\n      this._lastResult = await this.fn(...args)\n      this._successCount++\n      this._options.onSuccess?.(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError?.(error, this)\n    } finally {\n      this._settleCount++\n      this._options.onSettled?.(this)\n    }\n\n    return this._lastResult\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   */\n  getMsUntilNextWindow(): number {\n    return this.getRemainingInWindow() * this._options.window\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has been settled\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._successCount = 0\n    this._errorCount = 0\n    this._rejectionCount = 0\n    this._settleCount = 0\n  }\n}\n\n/**\n * Creates an async rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute\n * const rateLimited = asyncRateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * await rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function asyncRateLimit<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncRateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new AsyncRateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":"AAwCA,MAAM,iBAEF;AAAA,EACF,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAA;AACnB;AA2BO,MAAM,iBAA+C;AAAA,EAS1D,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AARV,SAAQ,cAAc;AACtB,SAAQ,kBAAiC,CAAC;AAE1C,SAAQ,kBAAkB;AAC1B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AAMtB,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAyD;AAClE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAqD;AACnD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAmBd,MAAM,gBACD,MACmC;AACtC,SAAK,qBAAqB;AAE1B,QAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC/C,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA;AAGd,SAAK,eAAe;AACb,WAAA;AAAA,EAAA;AAAA,EAGT,MAAc,mBACT,MACmC;AArG1C;AAsGQ,QAAA,CAAC,KAAK,SAAS,QAAS;AACtB,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA,gBAAgB,KAAK,GAAG;AAEzB,QAAA;AACF,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,uBAAK,UAAS,cAAd,4BAA0B,KAAK,aAAc;AAAA,aACtC,OAAO;AACT,WAAA;AACA,uBAAA,UAAS,YAAT,4BAAmB,OAAO;AAAA,IAAI,UACnC;AACK,WAAA;AACA,uBAAA,UAAS,cAAT,4BAAqB;AAAA,IAAI;AAGhC,WAAO,KAAK;AAAA,EAAA;AAAA,EAGN,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtE,uBAA+B;AAC7B,WAAO,KAAK,qBAAA,IAAyB,KAAK,SAAS;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMrD,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,gBAAgB;AACrB,SAAK,cAAc;AACnB,SAAK,kBAAkB;AACvB,SAAK,eAAe;AAAA,EAAA;AAExB;AAgCgB,SAAA,eACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,iBAAiB,IAAI,cAAc;AACpD,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;"}
+{"version":3,"file":"async-rate-limiter.js","sources":["../../src/async-rate-limiter.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async rate-limited function\n */\nexport interface AsyncRateLimiterOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Optional error handler for when the rate-limited function throws\n   */\n  onError?: (error: unknown, rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSettled?: (rateLimiter: AsyncRateLimiter<TFn>) => void\n  /**\n   * Optional function to call when the rate-limited function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    rateLimiter: AsyncRateLimiter<TFn>,\n  ) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n  /**\n   * Type of window to use for rate limiting\n   * - 'fixed': Uses a fixed window that resets after the window period\n   * - 'sliding': Uses a sliding window that allows executions as old ones expire\n   * Defaults to 'fixed'\n   */\n  windowType?: 'fixed' | 'sliding'\n}\n\nconst defaultOptions: Required<\n  Omit<AsyncRateLimiterOptions<any>, 'limit' | 'window'>\n> = {\n  enabled: true,\n  onError: () => {},\n  onReject: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  windowType: 'fixed',\n}\n\n/**\n * A class that creates an async rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * Unlike the non-async RateLimiter, this async version supports returning values from the rate-limited function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the rate-limited function.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new AsyncRateLimiter(\n *   async (id: string) => await api.getData(id),\n *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window\n * );\n *\n * // Will execute immediately until limit reached, then block\n * // Returns the API response directly\n * const data = await rateLimiter.maybeExecute('123');\n * ```\n */\nexport class AsyncRateLimiter<TFn extends AnyAsyncFunction> {\n  private _options: AsyncRateLimiterOptions<TFn>\n  private _errorCount = 0\n  private _executionTimes: Array<number> = []\n  private _lastResult: ReturnType<TFn> | undefined\n  private _rejectionCount = 0\n  private _settleCount = 0\n  private _successCount = 0\n  private _isExecuting = false\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncRateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncRateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<AsyncRateLimiterOptions<TFn>> {\n    return this._options as Required<AsyncRateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   * If execution is allowed, waits for any previous execution to complete before proceeding.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new AsyncRateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will execute\n   * await rateLimiter.maybeExecute('arg1', 'arg2');\n   *\n   * // Additional calls within the window will be rejected\n   * await rateLimiter.maybeExecute('arg1', 'arg2'); // Rejected\n   * ```\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    this.cleanupOldExecutions()\n\n    if (this._options.windowType === 'sliding') {\n      // For sliding window, we can execute if we have capacity in the current window\n      if (this._executionTimes.length < this._options.limit) {\n        await this.executeFunction(...args)\n        return this._lastResult\n      }\n    } else {\n      // For fixed window, we need to check if we're in a new window\n      const now = Date.now()\n      const oldestExecution = Math.min(...this._executionTimes)\n      const isNewWindow = oldestExecution + this._options.window <= now\n\n      if (isNewWindow || this._executionTimes.length < this._options.limit) {\n        await this.executeFunction(...args)\n        return this._lastResult\n      }\n    }\n\n    this.rejectFunction()\n    return undefined\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled) return\n    this._isExecuting = true\n    const now = Date.now()\n    this._executionTimes.push(now)\n\n    try {\n      this._lastResult = await this.fn(...args)\n      this._successCount++\n      this._options.onSuccess?.(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError?.(error, this)\n    } finally {\n      this._isExecuting = false\n      this._settleCount++\n      this._options.onSettled?.(this)\n    }\n\n    return this._lastResult\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   * For fixed windows, this is the time until the current window resets\n   * For sliding windows, this is the time until the oldest execution expires\n   */\n  getMsUntilNextWindow(): number {\n    if (this.getRemainingInWindow() > 0) {\n      return 0\n    }\n    const oldestExecution = Math.min(...this._executionTimes)\n    return oldestExecution + this._options.window - Date.now()\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has been settled\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Returns whether the function is currently executing\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._successCount = 0\n    this._errorCount = 0\n    this._rejectionCount = 0\n    this._settleCount = 0\n  }\n}\n\n/**\n * Creates an async rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Unlike the non-async rate limiter, this async version supports returning values from the rate-limited function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the rate-limited function.\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute with a sliding window\n * const rateLimited = asyncRateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   windowType: 'sliding',\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * // Returns the API response directly\n * const result = await rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function asyncRateLimit<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncRateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new AsyncRateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":"AA+CA,MAAM,iBAEF;AAAA,EACF,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,YAAY;AACd;AAsCO,MAAM,iBAA+C;AAAA,EAU1D,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AATV,SAAQ,cAAc;AACtB,SAAQ,kBAAiC,CAAC;AAE1C,SAAQ,kBAAkB;AAC1B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,eAAe;AAMrB,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAyD;AAClE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAqD;AACnD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAmBd,MAAM,gBACD,MACmC;AACtC,SAAK,qBAAqB;AAEtB,QAAA,KAAK,SAAS,eAAe,WAAW;AAE1C,UAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC/C,cAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,eAAO,KAAK;AAAA,MAAA;AAAA,IACd,OACK;AAEC,YAAA,MAAM,KAAK,IAAI;AACrB,YAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,YAAM,cAAc,kBAAkB,KAAK,SAAS,UAAU;AAE9D,UAAI,eAAe,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC9D,cAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,eAAO,KAAK;AAAA,MAAA;AAAA,IACd;AAGF,SAAK,eAAe;AACb,WAAA;AAAA,EAAA;AAAA,EAGT,MAAc,mBACT,MACmC;AA/H1C;AAgIQ,QAAA,CAAC,KAAK,SAAS,QAAS;AAC5B,SAAK,eAAe;AACd,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA,gBAAgB,KAAK,GAAG;AAEzB,QAAA;AACF,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,uBAAK,UAAS,cAAd,4BAA0B,KAAK,aAAc;AAAA,aACtC,OAAO;AACT,WAAA;AACA,uBAAA,UAAS,YAAT,4BAAmB,OAAO;AAAA,IAAI,UACnC;AACA,WAAK,eAAe;AACf,WAAA;AACA,uBAAA,UAAS,cAAT,4BAAqB;AAAA,IAAI;AAGhC,WAAO,KAAK;AAAA,EAAA;AAAA,EAGN,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAQtE,uBAA+B;AACzB,QAAA,KAAK,qBAAqB,IAAI,GAAG;AAC5B,aAAA;AAAA,IAAA;AAET,UAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,WAAO,kBAAkB,KAAK,SAAS,SAAS,KAAK,IAAI;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAM3D,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,gBAAgB;AACrB,SAAK,cAAc;AACnB,SAAK,kBAAkB;AACvB,SAAK,eAAe;AAAA,EAAA;AAExB;AA4CgB,SAAA,eACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,iBAAiB,IAAI,cAAc;AACpD,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;"}

dist/esm/async-throttler.d.ts

@@ -46,2 +46,6 @@ import { AnyAsyncFunction } from './types.js';
  *
+ * Unlike the non-async Throttler, this async version supports returning values from the throttled function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the throttled function.
+ *
  * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to
@@ -53,9 +57,9 @@ * ensure a maximum execution frequency.
  * const throttler = new AsyncThrottler(async (value: string) => {
- *   await saveToAPI(value);
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // Will only execute once per second no matter how often called
- * inputElement.addEventListener('input', () => {
- *   throttler.maybeExecute(inputElement.value);
- * });
+ * // Returns the API response directly
+ * const result = await throttler.maybeExecute(inputElement.value);
  * ```
@@ -134,13 +138,18 @@ */
  *
+ * Unlike the non-async Throttler, this async version supports returning values from the throttled function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the throttled function.
+ *
  * @example
  * ```ts
- * const throttled = asyncThrottle(async () => {
- *   await someAsyncOperation();
+ * const throttled = asyncThrottle(async (value: string) => {
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // This will execute at most once per second
- * await throttled();
- * await throttled(); // Waits 1 second before executing
+ * // Returns the API response directly
+ * const result = await throttled(inputElement.value);
  * ```
  */
 export declare function asyncThrottle<TFn extends AnyAsyncFunction>(fn: TFn, initialOptions: Omit<AsyncThrottlerOptions<TFn>, 'enabled'>): (...args: Parameters<TFn>) => Promise<ReturnType<TFn> | undefined>;

dist/esm/async-throttler.js.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"async-throttler.js","sources":["../../src/async-throttler.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async throttled function\n */\nexport interface AsyncThrottlerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the throttler is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute the function immediately when called\n   * Defaults to true\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the throttled function throws\n   */\n  onError?: (error: unknown, asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSettled?: (asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    asyncThrottler: AsyncThrottler<TFn>,\n  ) => void\n  /**\n   * Whether to execute the function on the trailing edge of the wait period\n   * Defaults to true\n   */\n  trailing?: boolean\n  /**\n   * Time window in milliseconds during which the function can only be executed once\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncThrottlerOptions<any>> = {\n  enabled: true,\n  leading: true,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async throttled function.\n *\n * Throttling limits how often a function can be executed, allowing only one execution within a specified time window.\n * Unlike debouncing which resets the delay timer on each call, throttling ensures the function executes at a\n * regular interval regardless of how often it's called.\n *\n * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to\n * ensure a maximum execution frequency.\n *\n * @example\n * ```ts\n * const throttler = new AsyncThrottler(async (value: string) => {\n *   await saveToAPI(value);\n * }, { wait: 1000 });\n *\n * // Will only execute once per second no matter how often called\n * inputElement.addEventListener('input', () => {\n *   throttler.maybeExecute(inputElement.value);\n * });\n * ```\n */\nexport class AsyncThrottler<TFn extends AnyAsyncFunction> {\n  private _options: Required<AsyncThrottlerOptions<TFn>>\n  private _abortController: AbortController | null = null\n  private _errorCount = 0\n  private _isExecuting = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastExecutionTime = 0\n  private _lastResult: ReturnType<TFn> | undefined\n  private _nextExecutionTime = 0\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncThrottlerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the throttler options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncThrottlerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this.cancel()\n    }\n  }\n\n  /**\n   * Returns the current options\n   */\n  getOptions(): Required<AsyncThrottlerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the throttled function\n   * If a call is already in progress, it may be blocked or queued depending on the `wait` option\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    const now = Date.now()\n    const timeSinceLastExecution = now - this._lastExecutionTime\n\n    // Handle leading execution\n    if (this._options.leading && timeSinceLastExecution >= this._options.wait) {\n      await this.executeFunction(...args)\n      return this._lastResult\n    } else {\n      // Store the most recent arguments for potential trailing execution\n      this._lastArgs = args\n\n      return new Promise((resolve) => {\n        // Clear any existing timeout to ensure we use the latest arguments\n        if (this._timeoutId) {\n          clearTimeout(this._timeoutId)\n        }\n\n        // Set up trailing execution if enabled\n        if (this._options.trailing) {\n          const _timeSinceLastExecution = this._lastExecutionTime\n            ? now - this._lastExecutionTime\n            : 0\n          const timeoutDuration = this._options.wait - _timeSinceLastExecution\n          this._timeoutId = setTimeout(async () => {\n            if (this._lastArgs !== undefined) {\n              await this.executeFunction(...this._lastArgs)\n            }\n            resolve(this._lastResult)\n          }, timeoutDuration)\n        }\n      })\n    }\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled || this._isExecuting) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._settleCount++\n      this._abortController = null\n      this._lastExecutionTime = Date.now()\n      this._nextExecutionTime = this._lastExecutionTime + this._options.wait\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n  }\n\n  /**\n   * Returns the last execution time\n   */\n  getLastExecutionTime(): number {\n    return this._lastExecutionTime\n  }\n\n  /**\n   * Returns the next execution time\n   */\n  getNextExecutionTime(): number {\n    return this._nextExecutionTime\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the current pending state\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && !!this._timeoutId\n  }\n\n  /**\n   * Returns the current executing state\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async throttled function that limits how often the function can execute.\n * The throttled function will execute at most once per wait period, even if called multiple times.\n * If called while executing, it will wait until execution completes before scheduling the next call.\n *\n * @example\n * ```ts\n * const throttled = asyncThrottle(async () => {\n *   await someAsyncOperation();\n * }, { wait: 1000 });\n *\n * // This will execute at most once per second\n * await throttled();\n * await throttled(); // Waits 1 second before executing\n * ```\n */\nexport function asyncThrottle<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncThrottlerOptions<TFn>, 'enabled'>,\n) {\n  const asyncThrottler = new AsyncThrottler(fn, initialOptions)\n  return asyncThrottler.maybeExecute.bind(asyncThrottler)\n}\n"],"names":[],"mappings":"AA2CA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AAwBO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAZV,SAAQ,mBAA2C;AACnD,SAAQ,cAAc;AACtB,SAAQ,eAAe;AAEvB,SAAQ,qBAAqB;AAE7B,SAAQ,qBAAqB;AAC7B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,OAAO;AAAA,IAAA;AAAA,EACd;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AAChC,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,yBAAyB,MAAM,KAAK;AAG1C,QAAI,KAAK,SAAS,WAAW,0BAA0B,KAAK,SAAS,MAAM;AACnE,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA,OACP;AAEL,WAAK,YAAY;AAEV,aAAA,IAAI,QAAQ,CAAC,YAAY;AAE9B,YAAI,KAAK,YAAY;AACnB,uBAAa,KAAK,UAAU;AAAA,QAAA;AAI1B,YAAA,KAAK,SAAS,UAAU;AAC1B,gBAAM,0BAA0B,KAAK,qBACjC,MAAM,KAAK,qBACX;AACE,gBAAA,kBAAkB,KAAK,SAAS,OAAO;AACxC,eAAA,aAAa,WAAW,YAAY;AACnC,gBAAA,KAAK,cAAc,QAAW;AAChC,oBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,YAAA;AAE9C,oBAAQ,KAAK,WAAW;AAAA,aACvB,eAAe;AAAA,QAAA;AAAA,MACpB,CACD;AAAA,IAAA;AAAA,EACH;AAAA,EAGF,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,WAAW,KAAK,aAAqB,QAAA;AACnD,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACf,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,qBAAqB,KAAK,IAAI;AACnC,WAAK,qBAAqB,KAAK,qBAAqB,KAAK,SAAS;AAC7D,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,SAAe;AACb,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMnB,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACtB,WAAO,KAAK,SAAS,WAAW,CAAC,CAAC,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMzC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAkBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;"}
+{"version":3,"file":"async-throttler.js","sources":["../../src/async-throttler.ts"],"sourcesContent":["import type { AnyAsyncFunction } from './types'\n\n/**\n * Options for configuring an async throttled function\n */\nexport interface AsyncThrottlerOptions<TFn extends AnyAsyncFunction> {\n  /**\n   * Whether the throttler is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Whether to execute the function immediately when called\n   * Defaults to true\n   */\n  leading?: boolean\n  /**\n   * Optional error handler for when the throttled function throws\n   */\n  onError?: (error: unknown, asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSettled?: (asyncThrottler: AsyncThrottler<TFn>) => void\n  /**\n   * Optional function to call when the throttled function is executed\n   */\n  onSuccess?: (\n    result: ReturnType<TFn>,\n    asyncThrottler: AsyncThrottler<TFn>,\n  ) => void\n  /**\n   * Whether to execute the function on the trailing edge of the wait period\n   * Defaults to true\n   */\n  trailing?: boolean\n  /**\n   * Time window in milliseconds during which the function can only be executed once\n   * Defaults to 0ms\n   */\n  wait: number\n}\n\nconst defaultOptions: Required<AsyncThrottlerOptions<any>> = {\n  enabled: true,\n  leading: true,\n  onError: () => {},\n  onSettled: () => {},\n  onSuccess: () => {},\n  trailing: true,\n  wait: 0,\n}\n\n/**\n * A class that creates an async throttled function.\n *\n * Throttling limits how often a function can be executed, allowing only one execution within a specified time window.\n * Unlike debouncing which resets the delay timer on each call, throttling ensures the function executes at a\n * regular interval regardless of how often it's called.\n *\n * Unlike the non-async Throttler, this async version supports returning values from the throttled function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the throttled function.\n *\n * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to\n * ensure a maximum execution frequency.\n *\n * @example\n * ```ts\n * const throttler = new AsyncThrottler(async (value: string) => {\n *   const result = await saveToAPI(value);\n *   return result; // Return value is preserved\n * }, { wait: 1000 });\n *\n * // Will only execute once per second no matter how often called\n * // Returns the API response directly\n * const result = await throttler.maybeExecute(inputElement.value);\n * ```\n */\nexport class AsyncThrottler<TFn extends AnyAsyncFunction> {\n  private _options: Required<AsyncThrottlerOptions<TFn>>\n  private _abortController: AbortController | null = null\n  private _errorCount = 0\n  private _isExecuting = false\n  private _lastArgs: Parameters<TFn> | undefined\n  private _lastExecutionTime = 0\n  private _lastResult: ReturnType<TFn> | undefined\n  private _nextExecutionTime = 0\n  private _settleCount = 0\n  private _successCount = 0\n  private _timeoutId: NodeJS.Timeout | null = null\n\n  constructor(\n    private fn: TFn,\n    initialOptions: AsyncThrottlerOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the throttler options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<AsyncThrottlerOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n\n    // End the pending state if the debouncer is disabled\n    if (!this._options.enabled) {\n      this.cancel()\n    }\n  }\n\n  /**\n   * Returns the current options\n   */\n  getOptions(): Required<AsyncThrottlerOptions<TFn>> {\n    return this._options\n  }\n\n  /**\n   * Attempts to execute the throttled function\n   * If a call is already in progress, it may be blocked or queued depending on the `wait` option\n   */\n  async maybeExecute(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    const now = Date.now()\n    const timeSinceLastExecution = now - this._lastExecutionTime\n\n    // Handle leading execution\n    if (this._options.leading && timeSinceLastExecution >= this._options.wait) {\n      await this.executeFunction(...args)\n      return this._lastResult\n    } else {\n      // Store the most recent arguments for potential trailing execution\n      this._lastArgs = args\n\n      return new Promise((resolve) => {\n        // Clear any existing timeout to ensure we use the latest arguments\n        if (this._timeoutId) {\n          clearTimeout(this._timeoutId)\n        }\n\n        // Set up trailing execution if enabled\n        if (this._options.trailing) {\n          const _timeSinceLastExecution = this._lastExecutionTime\n            ? now - this._lastExecutionTime\n            : 0\n          const timeoutDuration = this._options.wait - _timeSinceLastExecution\n          this._timeoutId = setTimeout(async () => {\n            if (this._lastArgs !== undefined) {\n              await this.executeFunction(...this._lastArgs)\n            }\n            resolve(this._lastResult)\n          }, timeoutDuration)\n        }\n      })\n    }\n  }\n\n  private async executeFunction(\n    ...args: Parameters<TFn>\n  ): Promise<ReturnType<TFn> | undefined> {\n    if (!this._options.enabled || this._isExecuting) return undefined\n    this._abortController = new AbortController()\n    try {\n      this._isExecuting = true\n      this._lastResult = await this.fn(...args) // EXECUTE!\n      this._successCount++\n      this._options.onSuccess(this._lastResult!, this)\n    } catch (error) {\n      this._errorCount++\n      this._options.onError(error, this)\n    } finally {\n      this._isExecuting = false\n      this._settleCount++\n      this._abortController = null\n      this._lastExecutionTime = Date.now()\n      this._nextExecutionTime = this._lastExecutionTime + this._options.wait\n      this._options.onSettled(this)\n    }\n    return this._lastResult\n  }\n\n  /**\n   * Cancels any pending execution or aborts any execution in progress\n   */\n  cancel(): void {\n    if (this._timeoutId) {\n      clearTimeout(this._timeoutId)\n      this._timeoutId = null\n    }\n    if (this._abortController) {\n      this._abortController.abort()\n      this._abortController = null\n    }\n    this._lastArgs = undefined\n  }\n\n  /**\n   * Returns the last execution time\n   */\n  getLastExecutionTime(): number {\n    return this._lastExecutionTime\n  }\n\n  /**\n   * Returns the next execution time\n   */\n  getNextExecutionTime(): number {\n    return this._nextExecutionTime\n  }\n\n  /**\n   * Returns the last result of the debounced function\n   */\n  getLastResult(): ReturnType<TFn> | undefined {\n    return this._lastResult\n  }\n\n  /**\n   * Returns the number of times the function has been executed successfully\n   */\n  getSuccessCount(): number {\n    return this._successCount\n  }\n\n  /**\n   * Returns the number of times the function has settled (completed or errored)\n   */\n  getSettleCount(): number {\n    return this._settleCount\n  }\n\n  /**\n   * Returns the number of times the function has errored\n   */\n  getErrorCount(): number {\n    return this._errorCount\n  }\n\n  /**\n   * Returns the current pending state\n   */\n  getIsPending(): boolean {\n    return this._options.enabled && !!this._timeoutId\n  }\n\n  /**\n   * Returns the current executing state\n   */\n  getIsExecuting(): boolean {\n    return this._isExecuting\n  }\n}\n\n/**\n * Creates an async throttled function that limits how often the function can execute.\n * The throttled function will execute at most once per wait period, even if called multiple times.\n * If called while executing, it will wait until execution completes before scheduling the next call.\n *\n * Unlike the non-async Throttler, this async version supports returning values from the throttled function,\n * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call\n * instead of setting the result on a state variable from within the throttled function.\n *\n * @example\n * ```ts\n * const throttled = asyncThrottle(async (value: string) => {\n *   const result = await saveToAPI(value);\n *   return result; // Return value is preserved\n * }, { wait: 1000 });\n *\n * // This will execute at most once per second\n * // Returns the API response directly\n * const result = await throttled(inputElement.value);\n * ```\n */\nexport function asyncThrottle<TFn extends AnyAsyncFunction>(\n  fn: TFn,\n  initialOptions: Omit<AsyncThrottlerOptions<TFn>, 'enabled'>,\n) {\n  const asyncThrottler = new AsyncThrottler(fn, initialOptions)\n  return asyncThrottler.maybeExecute.bind(asyncThrottler)\n}\n"],"names":[],"mappings":"AA2CA,MAAM,iBAAuD;AAAA,EAC3D,SAAS;AAAA,EACT,SAAS;AAAA,EACT,SAAS,MAAM;AAAA,EAAC;AAAA,EAChB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU;AAAA,EACV,MAAM;AACR;AA4BO,MAAM,eAA6C;AAAA,EAaxD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AAZV,SAAQ,mBAA2C;AACnD,SAAQ,cAAc;AACtB,SAAQ,eAAe;AAEvB,SAAQ,qBAAqB;AAE7B,SAAQ,qBAAqB;AAC7B,SAAQ,eAAe;AACvB,SAAQ,gBAAgB;AACxB,SAAQ,aAAoC;AAM1C,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAuD;AAChE,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAG9C,QAAA,CAAC,KAAK,SAAS,SAAS;AAC1B,WAAK,OAAO;AAAA,IAAA;AAAA,EACd;AAAA;AAAA;AAAA;AAAA,EAMF,aAAmD;AACjD,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOd,MAAM,gBACD,MACmC;AAChC,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,yBAAyB,MAAM,KAAK;AAG1C,QAAI,KAAK,SAAS,WAAW,0BAA0B,KAAK,SAAS,MAAM;AACnE,YAAA,KAAK,gBAAgB,GAAG,IAAI;AAClC,aAAO,KAAK;AAAA,IAAA,OACP;AAEL,WAAK,YAAY;AAEV,aAAA,IAAI,QAAQ,CAAC,YAAY;AAE9B,YAAI,KAAK,YAAY;AACnB,uBAAa,KAAK,UAAU;AAAA,QAAA;AAI1B,YAAA,KAAK,SAAS,UAAU;AAC1B,gBAAM,0BAA0B,KAAK,qBACjC,MAAM,KAAK,qBACX;AACE,gBAAA,kBAAkB,KAAK,SAAS,OAAO;AACxC,eAAA,aAAa,WAAW,YAAY;AACnC,gBAAA,KAAK,cAAc,QAAW;AAChC,oBAAM,KAAK,gBAAgB,GAAG,KAAK,SAAS;AAAA,YAAA;AAE9C,oBAAQ,KAAK,WAAW;AAAA,aACvB,eAAe;AAAA,QAAA;AAAA,MACpB,CACD;AAAA,IAAA;AAAA,EACH;AAAA,EAGF,MAAc,mBACT,MACmC;AACtC,QAAI,CAAC,KAAK,SAAS,WAAW,KAAK,aAAqB,QAAA;AACnD,SAAA,mBAAmB,IAAI,gBAAgB;AACxC,QAAA;AACF,WAAK,eAAe;AACpB,WAAK,cAAc,MAAM,KAAK,GAAG,GAAG,IAAI;AACnC,WAAA;AACL,WAAK,SAAS,UAAU,KAAK,aAAc,IAAI;AAAA,aACxC,OAAO;AACT,WAAA;AACA,WAAA,SAAS,QAAQ,OAAO,IAAI;AAAA,IAAA,UACjC;AACA,WAAK,eAAe;AACf,WAAA;AACL,WAAK,mBAAmB;AACnB,WAAA,qBAAqB,KAAK,IAAI;AACnC,WAAK,qBAAqB,KAAK,qBAAqB,KAAK,SAAS;AAC7D,WAAA,SAAS,UAAU,IAAI;AAAA,IAAA;AAE9B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,SAAe;AACb,QAAI,KAAK,YAAY;AACnB,mBAAa,KAAK,UAAU;AAC5B,WAAK,aAAa;AAAA,IAAA;AAEpB,QAAI,KAAK,kBAAkB;AACzB,WAAK,iBAAiB,MAAM;AAC5B,WAAK,mBAAmB;AAAA,IAAA;AAE1B,SAAK,YAAY;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMnB,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAA6C;AAC3C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,kBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,iBAAyB;AACvB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,gBAAwB;AACtB,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,eAAwB;AACtB,WAAO,KAAK,SAAS,WAAW,CAAC,CAAC,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMzC,iBAA0B;AACxB,WAAO,KAAK;AAAA,EAAA;AAEhB;AAuBgB,SAAA,cACd,IACA,gBACA;AACA,QAAM,iBAAiB,IAAI,eAAe,IAAI,cAAc;AACrD,SAAA,eAAe,aAAa,KAAK,cAAc;AACxD;"}

dist/esm/rate-limiter.d.ts

@@ -27,2 +27,9 @@ import { AnyFunction } from './types.js';
     window: number;
+    /**
+     * Type of window to use for rate limiting
+     * - 'fixed': Uses a fixed window that resets after the window period
+     * - 'sliding': Uses a sliding window that allows executions as old ones expire
+     * Defaults to 'fixed'
+     */
+    windowType?: 'fixed' | 'sliding';
 }
@@ -36,2 +43,8 @@ /**
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * For smoother execution patterns, consider using:
@@ -48,3 +61,3 @@ * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)
  *   (id: string) => api.getData(id),
- *   { limit: 5, window: 1000 } // 5 calls per second
+ *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window
  * );
@@ -120,2 +133,8 @@ *
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically
@@ -126,6 +145,7 @@ * need to enforce a hard limit on the number of executions within a time period.
  * ```ts
- * // Rate limit to 5 calls per minute
+ * // Rate limit to 5 calls per minute with a sliding window
  * const rateLimited = rateLimit(makeApiCall, {
  *   limit: 5,
  *   window: 60000,
+ *   windowType: 'sliding',
  *   onReject: (rateLimiter) => {
@@ -132,0 +152,0 @@ *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);

dist/esm/rate-limiter.js

@@ -8,3 +8,4 @@ const defaultOptions = {
   },
-  window: 0
+  window: 0,
+  windowType: "fixed"
 };
@@ -52,5 +53,15 @@ class RateLimiter {
     this.cleanupOldExecutions();
-    if (this._executionTimes.length < this._options.limit) {
-      this.executeFunction(...args);
-      return true;
+    if (this._options.windowType === "sliding") {
+      if (this._executionTimes.length < this._options.limit) {
+        this.executeFunction(...args);
+        return true;
+      }
+    } else {
+      const now = Date.now();
+      const oldestExecution = Math.min(...this._executionTimes);
+      const isNewWindow = oldestExecution + this._options.window <= now;
+      if (isNewWindow || this._executionTimes.length < this._options.limit) {
+        this.executeFunction(...args);
+        return true;
+      }
     }
@@ -105,2 +116,5 @@ this.rejectFunction();
   getMsUntilNextWindow() {
+    if (this.getRemainingInWindow() > 0) {
+      return 0;
+    }
     const oldestExecution = Math.min(...this._executionTimes);
@@ -107,0 +121,0 @@ return oldestExecution + this._options.window - Date.now();

dist/esm/rate-limiter.js.map

@@ -1,1 +0,1 @@
-{"version":3,"file":"rate-limiter.js","sources":["../../src/rate-limiter.ts"],"sourcesContent":["import type { AnyFunction } from './types'\n\n/**\n * Options for configuring a rate-limited function\n */\nexport interface RateLimiterOptions<TFn extends AnyFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Callback function that is called after the function is executed\n   */\n  onExecute?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n}\n\nconst defaultOptions: Required<RateLimiterOptions<any>> = {\n  enabled: true,\n  limit: 1,\n  onExecute: () => {},\n  onReject: () => {},\n  window: 0,\n}\n\n/**\n * A class that creates a rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new RateLimiter(\n *   (id: string) => api.getData(id),\n *   { limit: 5, window: 1000 } // 5 calls per second\n * );\n *\n * // Will execute immediately until limit reached, then block\n * rateLimiter.maybeExecute('123');\n * ```\n */\nexport class RateLimiter<TFn extends AnyFunction> {\n  private _executionCount = 0\n  private _rejectionCount = 0\n  private _executionTimes: Array<number> = []\n  private _options: RateLimiterOptions<TFn>\n\n  constructor(\n    private fn: TFn,\n    initialOptions: RateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<RateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<RateLimiterOptions<TFn>> {\n    return this._options as Required<RateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new RateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will return true\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // true\n   *\n   * // Additional calls within the window will return false\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // false\n   * ```\n   */\n  maybeExecute(...args: Parameters<TFn>): boolean {\n    this.cleanupOldExecutions()\n\n    if (this._executionTimes.length < this._options.limit) {\n      this.executeFunction(...args)\n      return true\n    }\n\n    this.rejectFunction()\n\n    return false\n  }\n\n  private executeFunction(...args: Parameters<TFn>): void {\n    if (!this._options.enabled) return\n    const now = Date.now()\n    this._executionCount++\n    this._executionTimes.push(now)\n    this.fn(...args) // execute the function\n    this._options.onExecute?.(this)\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getExecutionCount(): number {\n    return this._executionCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   */\n  getMsUntilNextWindow(): number {\n    const oldestExecution = Math.min(...this._executionTimes)\n    return oldestExecution + this._options.window - Date.now()\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._executionCount = 0\n    this._rejectionCount = 0\n  }\n}\n\n/**\n * Creates a rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute\n * const rateLimited = rateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function rateLimit<TFn extends AnyFunction>(\n  fn: TFn,\n  initialOptions: Omit<RateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new RateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":"AA6BA,MAAM,iBAAoD;AAAA,EACxD,SAAS;AAAA,EACT,OAAO;AAAA,EACP,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,QAAQ;AACV;AA2BO,MAAM,YAAqC;AAAA,EAMhD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AANV,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAiC,CAAC;AAOxC,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAoD;AAC7D,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAgD;AAC9C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAkBd,gBAAgB,MAAgC;AAC9C,SAAK,qBAAqB;AAE1B,QAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAChD,WAAA,gBAAgB,GAAG,IAAI;AACrB,aAAA;AAAA,IAAA;AAGT,SAAK,eAAe;AAEb,WAAA;AAAA,EAAA;AAAA,EAGD,mBAAmB,MAA6B;AA5F1D;AA6FQ,QAAA,CAAC,KAAK,SAAS,QAAS;AACtB,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA;AACA,SAAA,gBAAgB,KAAK,GAAG;AACxB,SAAA,GAAG,GAAG,IAAI;AACV,qBAAA,UAAS,cAAT,4BAAqB;AAAA,EAAI;AAAA,EAGxB,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtE,uBAA+B;AAC7B,UAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,WAAO,kBAAkB,KAAK,SAAS,SAAS,KAAK,IAAI;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAM3D,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,kBAAkB;AACvB,SAAK,kBAAkB;AAAA,EAAA;AAE3B;AAgCgB,SAAA,UACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,YAAY,IAAI,cAAc;AAC/C,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;"}
+{"version":3,"file":"rate-limiter.js","sources":["../../src/rate-limiter.ts"],"sourcesContent":["import type { AnyFunction } from './types'\n\n/**\n * Options for configuring a rate-limited function\n */\nexport interface RateLimiterOptions<TFn extends AnyFunction> {\n  /**\n   * Whether the rate limiter is enabled. When disabled, maybeExecute will not trigger any executions.\n   * Defaults to true.\n   */\n  enabled?: boolean\n  /**\n   * Maximum number of executions allowed within the time window\n   */\n  limit: number\n  /**\n   * Callback function that is called after the function is executed\n   */\n  onExecute?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Optional callback function that is called when an execution is rejected due to rate limiting\n   */\n  onReject?: (rateLimiter: RateLimiter<TFn>) => void\n  /**\n   * Time window in milliseconds within which the limit applies\n   */\n  window: number\n  /**\n   * Type of window to use for rate limiting\n   * - 'fixed': Uses a fixed window that resets after the window period\n   * - 'sliding': Uses a sliding window that allows executions as old ones expire\n   * Defaults to 'fixed'\n   */\n  windowType?: 'fixed' | 'sliding'\n}\n\nconst defaultOptions: Required<RateLimiterOptions<any>> = {\n  enabled: true,\n  limit: 1,\n  onExecute: () => {},\n  onReject: () => {},\n  window: 0,\n  windowType: 'fixed',\n}\n\n/**\n * A class that creates a rate-limited function.\n *\n * Rate limiting is a simple approach that allows a function to execute up to a limit within a time window,\n * then blocks all subsequent calls until the window passes. This can lead to \"bursty\" behavior where\n * all executions happen immediately, followed by a complete block.\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * For smoother execution patterns, consider using:\n * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)\n * - Debouncing: Waits for a pause in calls before executing (e.g. after 500ms of no calls)\n *\n * Rate limiting is best used for hard API limits or resource constraints. For UI updates or\n * smoothing out frequent events, throttling or debouncing usually provide better user experience.\n *\n * @example\n * ```ts\n * const rateLimiter = new RateLimiter(\n *   (id: string) => api.getData(id),\n *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window\n * );\n *\n * // Will execute immediately until limit reached, then block\n * rateLimiter.maybeExecute('123');\n * ```\n */\nexport class RateLimiter<TFn extends AnyFunction> {\n  private _executionCount = 0\n  private _rejectionCount = 0\n  private _executionTimes: Array<number> = []\n  private _options: RateLimiterOptions<TFn>\n\n  constructor(\n    private fn: TFn,\n    initialOptions: RateLimiterOptions<TFn>,\n  ) {\n    this._options = {\n      ...defaultOptions,\n      ...initialOptions,\n    }\n  }\n\n  /**\n   * Updates the rate limiter options\n   * Returns the new options state\n   */\n  setOptions(newOptions: Partial<RateLimiterOptions<TFn>>): void {\n    this._options = { ...this._options, ...newOptions }\n  }\n\n  /**\n   * Returns the current rate limiter options\n   */\n  getOptions(): Required<RateLimiterOptions<TFn>> {\n    return this._options as Required<RateLimiterOptions<TFn>>\n  }\n\n  /**\n   * Attempts to execute the rate-limited function if within the configured limits.\n   * Will reject execution if the number of calls in the current window exceeds the limit.\n   *\n   * @example\n   * ```ts\n   * const rateLimiter = new RateLimiter(fn, { limit: 5, window: 1000 });\n   *\n   * // First 5 calls will return true\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // true\n   *\n   * // Additional calls within the window will return false\n   * rateLimiter.maybeExecute('arg1', 'arg2'); // false\n   * ```\n   */\n  maybeExecute(...args: Parameters<TFn>): boolean {\n    this.cleanupOldExecutions()\n\n    if (this._options.windowType === 'sliding') {\n      // For sliding window, we can execute if we have capacity in the current window\n      if (this._executionTimes.length < this._options.limit) {\n        this.executeFunction(...args)\n        return true\n      }\n    } else {\n      // For fixed window, we need to check if we're in a new window\n      const now = Date.now()\n      const oldestExecution = Math.min(...this._executionTimes)\n      const isNewWindow = oldestExecution + this._options.window <= now\n\n      if (isNewWindow || this._executionTimes.length < this._options.limit) {\n        this.executeFunction(...args)\n        return true\n      }\n    }\n\n    this.rejectFunction()\n    return false\n  }\n\n  private executeFunction(...args: Parameters<TFn>): void {\n    if (!this._options.enabled) return\n    const now = Date.now()\n    this._executionCount++\n    this._executionTimes.push(now)\n    this.fn(...args) // execute the function\n    this._options.onExecute?.(this)\n  }\n\n  private rejectFunction(): void {\n    this._rejectionCount++\n    if (this._options.onReject) {\n      this._options.onReject(this)\n    }\n  }\n\n  private cleanupOldExecutions(): void {\n    const now = Date.now()\n    const windowStart = now - this._options.window\n    this._executionTimes = this._executionTimes.filter(\n      (time) => time > windowStart,\n    )\n  }\n\n  /**\n   * Returns the number of times the function has been executed\n   */\n  getExecutionCount(): number {\n    return this._executionCount\n  }\n\n  /**\n   * Returns the number of times the function has been rejected\n   */\n  getRejectionCount(): number {\n    return this._rejectionCount\n  }\n\n  /**\n   * Returns the number of remaining executions allowed in the current window\n   */\n  getRemainingInWindow(): number {\n    this.cleanupOldExecutions()\n    return Math.max(0, this._options.limit - this._executionTimes.length)\n  }\n\n  /**\n   * Returns the number of milliseconds until the next execution will be possible\n   */\n  getMsUntilNextWindow(): number {\n    if (this.getRemainingInWindow() > 0) {\n      return 0\n    }\n    const oldestExecution = Math.min(...this._executionTimes)\n    return oldestExecution + this._options.window - Date.now()\n  }\n\n  /**\n   * Resets the rate limiter state\n   */\n  reset(): void {\n    this._executionTimes = []\n    this._executionCount = 0\n    this._rejectionCount = 0\n  }\n}\n\n/**\n * Creates a rate-limited function that will execute the provided function up to a maximum number of times within a time window.\n *\n * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:\n * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets\n * - A throttler ensures even spacing between executions, which can be better for consistent performance\n * - A debouncer collapses multiple calls into one, which is better for handling bursts of events\n *\n * The rate limiter supports two types of windows:\n * - 'fixed': A strict window that resets after the window period. All executions within the window count\n *   towards the limit, and the window resets completely after the period.\n * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more\n *   consistent rate of execution over time.\n *\n * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically\n * need to enforce a hard limit on the number of executions within a time period.\n *\n * @example\n * ```ts\n * // Rate limit to 5 calls per minute with a sliding window\n * const rateLimited = rateLimit(makeApiCall, {\n *   limit: 5,\n *   window: 60000,\n *   windowType: 'sliding',\n *   onReject: (rateLimiter) => {\n *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);\n *   }\n * });\n *\n * // First 5 calls will execute immediately\n * // Additional calls will be rejected until the minute window resets\n * rateLimited();\n *\n * // For more even execution, consider using throttle instead:\n * const throttled = throttle(makeApiCall, { wait: 12000 }); // One call every 12 seconds\n * ```\n */\nexport function rateLimit<TFn extends AnyFunction>(\n  fn: TFn,\n  initialOptions: Omit<RateLimiterOptions<TFn>, 'enabled'>,\n) {\n  const rateLimiter = new RateLimiter(fn, initialOptions)\n  return rateLimiter.maybeExecute.bind(rateLimiter)\n}\n"],"names":[],"mappings":"AAoCA,MAAM,iBAAoD;AAAA,EACxD,SAAS;AAAA,EACT,OAAO;AAAA,EACP,WAAW,MAAM;AAAA,EAAC;AAAA,EAClB,UAAU,MAAM;AAAA,EAAC;AAAA,EACjB,QAAQ;AAAA,EACR,YAAY;AACd;AAiCO,MAAM,YAAqC;AAAA,EAMhD,YACU,IACR,gBACA;AAFQ,SAAA,KAAA;AANV,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAkB;AAC1B,SAAQ,kBAAiC,CAAC;AAOxC,SAAK,WAAW;AAAA,MACd,GAAG;AAAA,MACH,GAAG;AAAA,IACL;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAOF,WAAW,YAAoD;AAC7D,SAAK,WAAW,EAAE,GAAG,KAAK,UAAU,GAAG,WAAW;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMpD,aAAgD;AAC9C,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA,EAkBd,gBAAgB,MAAgC;AAC9C,SAAK,qBAAqB;AAEtB,QAAA,KAAK,SAAS,eAAe,WAAW;AAE1C,UAAI,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAChD,aAAA,gBAAgB,GAAG,IAAI;AACrB,eAAA;AAAA,MAAA;AAAA,IACT,OACK;AAEC,YAAA,MAAM,KAAK,IAAI;AACrB,YAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,YAAM,cAAc,kBAAkB,KAAK,SAAS,UAAU;AAE9D,UAAI,eAAe,KAAK,gBAAgB,SAAS,KAAK,SAAS,OAAO;AAC/D,aAAA,gBAAgB,GAAG,IAAI;AACrB,eAAA;AAAA,MAAA;AAAA,IACT;AAGF,SAAK,eAAe;AACb,WAAA;AAAA,EAAA;AAAA,EAGD,mBAAmB,MAA6B;AA/G1D;AAgHQ,QAAA,CAAC,KAAK,SAAS,QAAS;AACtB,UAAA,MAAM,KAAK,IAAI;AAChB,SAAA;AACA,SAAA,gBAAgB,KAAK,GAAG;AACxB,SAAA,GAAG,GAAG,IAAI;AACV,qBAAA,UAAS,cAAT,4BAAqB;AAAA,EAAI;AAAA,EAGxB,iBAAuB;AACxB,SAAA;AACD,QAAA,KAAK,SAAS,UAAU;AACrB,WAAA,SAAS,SAAS,IAAI;AAAA,IAAA;AAAA,EAC7B;AAAA,EAGM,uBAA6B;AAC7B,UAAA,MAAM,KAAK,IAAI;AACf,UAAA,cAAc,MAAM,KAAK,SAAS;AACnC,SAAA,kBAAkB,KAAK,gBAAgB;AAAA,MAC1C,CAAC,SAAS,OAAO;AAAA,IACnB;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMF,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,oBAA4B;AAC1B,WAAO,KAAK;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMd,uBAA+B;AAC7B,SAAK,qBAAqB;AACnB,WAAA,KAAK,IAAI,GAAG,KAAK,SAAS,QAAQ,KAAK,gBAAgB,MAAM;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAMtE,uBAA+B;AACzB,QAAA,KAAK,qBAAqB,IAAI,GAAG;AAC5B,aAAA;AAAA,IAAA;AAET,UAAM,kBAAkB,KAAK,IAAI,GAAG,KAAK,eAAe;AACxD,WAAO,kBAAkB,KAAK,SAAS,SAAS,KAAK,IAAI;AAAA,EAAA;AAAA;AAAA;AAAA;AAAA,EAM3D,QAAc;AACZ,SAAK,kBAAkB,CAAC;AACxB,SAAK,kBAAkB;AACvB,SAAK,kBAAkB;AAAA,EAAA;AAE3B;AAuCgB,SAAA,UACd,IACA,gBACA;AACA,QAAM,cAAc,IAAI,YAAY,IAAI,cAAc;AAC/C,SAAA,YAAY,aAAa,KAAK,WAAW;AAClD;"}

package.json

 {
   "name": "@tanstack/pacer",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "description": "Utilities for debouncing, throttling, rate-limiting, queuing, and more.",
@@ -5,0 +5,0 @@ "author": "Tanner Linsley",

src/async-debouncer.ts

@@ -61,12 +61,16 @@ import type { AnyAsyncFunction } from './types'
  *
+ * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the debounced function.
+ *
  * @example
  * ```ts
  * const asyncDebouncer = new AsyncDebouncer(async (value: string) => {
- *   await searchAPI(value);
+ *   const results = await searchAPI(value);
+ *   return results; // Return value is preserved
  * }, { wait: 500 });
  *
  * // Called on each keystroke but only executes after 500ms of no typing
- * inputElement.addEventListener('input', () => {
- *   asyncDebouncer.maybeExecute(inputElement.value);
- * });
+ * // Returns the API response directly
+ * const results = await asyncDebouncer.maybeExecute(inputElement.value);
  * ```
@@ -249,12 +253,16 @@ */
  *
+ * Unlike the non-async Debouncer, this async version supports returning values from the debounced function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the debounced function.
+ *
  * @example
  * ```ts
  * const debounced = asyncDebounce(async (value: string) => {
- *   await saveToAPI(value);
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // Will only execute once, 1 second after the last call
- * await debounced("first");  // Cancelled
- * await debounced("second"); // Cancelled
- * await debounced("third");  // Executes after 1s
+ * // Returns the API response directly
+ * const result = await debounced("third");
  * ```
@@ -261,0 +269,0 @@ */

src/async-rate-limiter.ts

@@ -21,2 +21,6 @@ import type { AnyAsyncFunction } from './types'
   /**
+   * Optional callback function that is called when an execution is rejected due to rate limiting
+   */
+  onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void
+  /**
    * Optional function to call when the rate-limited function is executed
@@ -33,9 +37,12 @@ */
   /**
-   * Optional callback function that is called when an execution is rejected due to rate limiting
+   * Time window in milliseconds within which the limit applies
    */
-  onReject?: (rateLimiter: AsyncRateLimiter<TFn>) => void
+  window: number
   /**
-   * Time window in milliseconds within which the limit applies
+   * Type of window to use for rate limiting
+   * - 'fixed': Uses a fixed window that resets after the window period
+   * - 'sliding': Uses a sliding window that allows executions as old ones expire
+   * Defaults to 'fixed'
    */
-  window: number
+  windowType?: 'fixed' | 'sliding'
 }
@@ -51,2 +58,3 @@
   onSuccess: () => {},
+  windowType: 'fixed',
 }
@@ -61,2 +69,12 @@
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
+ * Unlike the non-async RateLimiter, this async version supports returning values from the rate-limited function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the rate-limited function.
+ *
  * For smoother execution patterns, consider using:
@@ -73,7 +91,8 @@ * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)
  *   async (id: string) => await api.getData(id),
- *   { limit: 5, window: 1000 } // 5 calls per second
+ *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window
  * );
  *
  * // Will execute immediately until limit reached, then block
- * await rateLimiter.maybeExecute('123');
+ * // Returns the API response directly
+ * const data = await rateLimiter.maybeExecute('123');
  * ```
@@ -89,2 +108,3 @@ */
   private _successCount = 0
+  private _isExecuting = false
 
@@ -137,5 +157,18 @@ constructor(
 
-    if (this._executionTimes.length < this._options.limit) {
-      await this.executeFunction(...args)
-      return this._lastResult
+    if (this._options.windowType === 'sliding') {
+      // For sliding window, we can execute if we have capacity in the current window
+      if (this._executionTimes.length < this._options.limit) {
+        await this.executeFunction(...args)
+        return this._lastResult
+      }
+    } else {
+      // For fixed window, we need to check if we're in a new window
+      const now = Date.now()
+      const oldestExecution = Math.min(...this._executionTimes)
+      const isNewWindow = oldestExecution + this._options.window <= now
+
+      if (isNewWindow || this._executionTimes.length < this._options.limit) {
+        await this.executeFunction(...args)
+        return this._lastResult
+      }
     }
@@ -151,2 +184,3 @@
     if (!this._options.enabled) return
+    this._isExecuting = true
     const now = Date.now()
@@ -163,2 +197,3 @@ this._executionTimes.push(now)
     } finally {
+      this._isExecuting = false
       this._settleCount++
@@ -196,5 +231,11 @@ this._options.onSettled?.(this)
    * Returns the number of milliseconds until the next execution will be possible
+   * For fixed windows, this is the time until the current window resets
+   * For sliding windows, this is the time until the oldest execution expires
    */
   getMsUntilNextWindow(): number {
-    return this.getRemainingInWindow() * this._options.window
+    if (this.getRemainingInWindow() > 0) {
+      return 0
+    }
+    const oldestExecution = Math.min(...this._executionTimes)
+    return oldestExecution + this._options.window - Date.now()
   }
@@ -231,2 +272,9 @@
   /**
+   * Returns whether the function is currently executing
+   */
+  getIsExecuting(): boolean {
+    return this._isExecuting
+  }
+
+  /**
    * Resets the rate limiter state
@@ -246,2 +294,12 @@ */
  *
+ * Unlike the non-async rate limiter, this async version supports returning values from the rate-limited function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the rate-limited function.
+ *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * Note that rate limiting is a simpler form of execution control compared to throttling or debouncing:
@@ -257,6 +315,7 @@ * - A rate limiter will allow all executions until the limit is reached, then block all subsequent calls until the window resets
  * ```ts
- * // Rate limit to 5 calls per minute
+ * // Rate limit to 5 calls per minute with a sliding window
  * const rateLimited = asyncRateLimit(makeApiCall, {
  *   limit: 5,
  *   window: 60000,
+ *   windowType: 'sliding',
  *   onReject: (rateLimiter) => {
@@ -269,3 +328,4 @@ *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);
  * // Additional calls will be rejected until the minute window resets
- * await rateLimited();
+ * // Returns the API response directly
+ * const result = await rateLimited();
  *
@@ -272,0 +332,0 @@ * // For more even execution, consider using throttle instead:

src/async-throttler.ts

@@ -61,2 +61,6 @@ import type { AnyAsyncFunction } from './types'
  *
+ * Unlike the non-async Throttler, this async version supports returning values from the throttled function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the throttled function.
+ *
  * This is useful for rate-limiting API calls, handling scroll/resize events, or any scenario where you want to
@@ -68,9 +72,9 @@ * ensure a maximum execution frequency.
  * const throttler = new AsyncThrottler(async (value: string) => {
- *   await saveToAPI(value);
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // Will only execute once per second no matter how often called
- * inputElement.addEventListener('input', () => {
- *   throttler.maybeExecute(inputElement.value);
- * });
+ * // Returns the API response directly
+ * const result = await throttler.maybeExecute(inputElement.value);
  * ```
@@ -263,11 +267,16 @@ */
  *
+ * Unlike the non-async Throttler, this async version supports returning values from the throttled function,
+ * making it ideal for API calls and other async operations where you want the result of the `maybeExecute` call
+ * instead of setting the result on a state variable from within the throttled function.
+ *
  * @example
  * ```ts
- * const throttled = asyncThrottle(async () => {
- *   await someAsyncOperation();
+ * const throttled = asyncThrottle(async (value: string) => {
+ *   const result = await saveToAPI(value);
+ *   return result; // Return value is preserved
  * }, { wait: 1000 });
  *
  * // This will execute at most once per second
- * await throttled();
- * await throttled(); // Waits 1 second before executing
+ * // Returns the API response directly
+ * const result = await throttled(inputElement.value);
  * ```
@@ -274,0 +283,0 @@ */

src/rate-limiter.ts

@@ -28,2 +28,9 @@ import type { AnyFunction } from './types'
   window: number
+  /**
+   * Type of window to use for rate limiting
+   * - 'fixed': Uses a fixed window that resets after the window period
+   * - 'sliding': Uses a sliding window that allows executions as old ones expire
+   * Defaults to 'fixed'
+   */
+  windowType?: 'fixed' | 'sliding'
 }
@@ -37,2 +44,3 @@
   window: 0,
+  windowType: 'fixed',
 }
@@ -47,2 +55,8 @@
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * For smoother execution patterns, consider using:
@@ -59,3 +73,3 @@ * - Throttling: Ensures consistent spacing between executions (e.g. max once per 200ms)
  *   (id: string) => api.getData(id),
- *   { limit: 5, window: 1000 } // 5 calls per second
+ *   { limit: 5, window: 1000, windowType: 'sliding' } // 5 calls per second with sliding window
  * );
@@ -116,9 +130,21 @@ *
 
-    if (this._executionTimes.length < this._options.limit) {
-      this.executeFunction(...args)
-      return true
+    if (this._options.windowType === 'sliding') {
+      // For sliding window, we can execute if we have capacity in the current window
+      if (this._executionTimes.length < this._options.limit) {
+        this.executeFunction(...args)
+        return true
+      }
+    } else {
+      // For fixed window, we need to check if we're in a new window
+      const now = Date.now()
+      const oldestExecution = Math.min(...this._executionTimes)
+      const isNewWindow = oldestExecution + this._options.window <= now
+
+      if (isNewWindow || this._executionTimes.length < this._options.limit) {
+        this.executeFunction(...args)
+        return true
+      }
     }
 
     this.rejectFunction()
-
     return false
@@ -177,2 +203,5 @@ }
   getMsUntilNextWindow(): number {
+    if (this.getRemainingInWindow() > 0) {
+      return 0
+    }
     const oldestExecution = Math.min(...this._executionTimes)
@@ -200,2 +229,8 @@ return oldestExecution + this._options.window - Date.now()
  *
+ * The rate limiter supports two types of windows:
+ * - 'fixed': A strict window that resets after the window period. All executions within the window count
+ *   towards the limit, and the window resets completely after the period.
+ * - 'sliding': A rolling window that allows executions as old ones expire. This provides a more
+ *   consistent rate of execution over time.
+ *
  * Consider using throttle() or debounce() if you need more intelligent execution control. Use rate limiting when you specifically
@@ -206,6 +241,7 @@ * need to enforce a hard limit on the number of executions within a time period.
  * ```ts
- * // Rate limit to 5 calls per minute
+ * // Rate limit to 5 calls per minute with a sliding window
  * const rateLimited = rateLimit(makeApiCall, {
  *   limit: 5,
  *   window: 60000,
+ *   windowType: 'sliding',
  *   onReject: (rateLimiter) => {
@@ -212,0 +248,0 @@ *     console.log(`Rate limit exceeded. Try again in ${rateLimiter.getMsUntilNextWindow()}ms`);

No alert changes

Improved metrics

Total package byte prevSize

497011

7.08%

Lines of code

7280

3.78%

No dependency changes