vite-plugin-dts

What is vite-plugin-dts?

vite-plugin-dts is a Vite plugin that generates TypeScript declaration files (d.ts) for your project. It helps in ensuring type safety and better developer experience by providing type definitions for your code.

What are vite-plugin-dts's main functionalities?

Generate TypeScript Declarations

This feature allows you to automatically generate TypeScript declaration files for your project. By including the plugin in your Vite configuration, it will generate .d.ts files for your TypeScript code.

import dts from 'vite-plugin-dts';

export default {
  plugins: [dts()]
};

Custom Output Directory

You can specify a custom output directory for the generated declaration files. This is useful if you want to organize your type definitions in a specific folder.

import dts from 'vite-plugin-dts';

export default {
  plugins: [
    dts({
      outputDir: 'types'
    })
  ]
};

Include/Exclude Specific Files

This feature allows you to include or exclude specific files or folders from the declaration generation process. You can use glob patterns to specify the files to include or exclude.

import dts from 'vite-plugin-dts';

export default {
  plugins: [
    dts({
      include: ['src/**/*.ts'],
      exclude: ['src/excluded-folder/**']
    })
  ]
};

Other packages similar to vite-plugin-dts

tsc

The TypeScript compiler (tsc) can be used to generate declaration files. It is a more general tool compared to vite-plugin-dts and can be used in any TypeScript project, not just those using Vite. However, it requires more configuration and does not integrate as seamlessly with Vite.

rollup-plugin-dts

rollup-plugin-dts is a Rollup plugin that generates TypeScript declaration files. It is similar to vite-plugin-dts but is designed for use with Rollup instead of Vite. If you are using Rollup as your bundler, this plugin would be a better fit.

README

vite-plugin-dts

A Vite plugin that generates declaration files (*.d.ts) from .ts(x) or .vue source files when using Vite in library mode.

English | 中文

Install

pnpm i vite-plugin-dts -D

Usage

In vite.config.ts:

import { resolve } from 'path'
import { defineConfig } from 'vite'
import dts from 'vite-plugin-dts'

export default defineConfig({
  build: {
    lib: {
      entry: resolve(__dirname, 'src/index.ts'),
      name: 'MyLib',
      formats: ['es'],
      fileName: 'my-lib'
    }
  },
  plugins: [dts()]
})

By default, the generated declaration files are following the source structure.

If you want to merge all declarations into one file, just specify rollupTypes: true:

{
  plugins: [dts({ rollupTypes: true })]
}

If you start with official Vite template, you should specify the tsconfigPath:

{
  plugins: [dts({ tsconfigPath: './tsconfig.app.json' })]
}

Starting with 3.0.0, you can use this plugin with Rollup.

FAQ

Here are some FAQ's and solutions.

Type errors that are unable to infer types from packages in node_modules

This is an existing TypeScript issue where TypeScript infers types from packages located in node_modules through soft links (pnpm). A workaround is to add baseUrl to your tsconfig.json and specify the paths for these packages:

{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "third-lib": ["node_modules/third-lib"]
    }
  }
}

Internal Error occurs when using rollupTypes: true

Refer to this issue, it's due to a limitation of @microsoft/api-extractor or TypeScript resolver.

The main reason is that baseUrl is specified in tsconfig.json and non-standard paths are used directly when imported.

For example: baseUrl: 'src' is specified and importing from <root>/src/components/index.ts in <root>/src/index.ts, and import 'components' is used instead of import './components'.

Currently, you need to avoid the above situation, or use aliases instead (with the paths option).

Get module not found errors during build

This is likely due to incorrect configuration of the include property in your default tsconfig.json.

Due to some limitations, the plugin relies on the top-level tsconfig.json to resolve the files to include. Therefore, you need to specify the correct include property in the top-level tsconfig.json, or you can specify a configuration file path with the correct include property using the tsconfigPath option of the plugin. For example, in the Vite initial template, it is tsconfig.app.json.

You can refer to this comment.

Legacy

Missing some declaration files after build (before 1.7.0)

By default, the skipDiagnostics option is set to true which means type diagnostics will be skipped during the build process (some projects may have diagnostic tools such as vue-tsc). Files with type errors which interrupt the build process will not be emitted (declaration files won't be generated).

If your project doesn't use type diagnostic tools, you can set skipDiagnostics: false and logDiagnostics: true to turn on diagnostic and logging features of this plugin. Type errors during build will be logged to the terminal.

Type error when using both script and setup-script in Vue component (before 3.0.0)

This is usually caused by using the defineComponent function in both script and setup-script. When vue/compiler-sfc compiles these files, the default export result from script gets merged with the parameter object of defineComponent from setup-script. This is incompatible with parameters and types returned from defineComponent. This results in a type error.

Here is a simple example. You should remove the defineComponent in script and export a native object directly.

Options

import type ts from 'typescript'
import type { IExtractorConfigPrepareOptions, IExtractorInvokeOptions } from '@microsoft/api-extractor'
import type { LogLevel } from 'vite'

type MaybePromise<T> = T | Promise<T>

export type RollupConfig = Omit<
  IExtractorConfigPrepareOptions['configObject'],
  | 'projectFolder'
  | 'mainEntryPointFilePath'
  | 'compiler'
  | 'dtsRollup'
  >

export interface Resolver {
  /**
   * The name of the resolver
   *
   * The later resolver with the same name will overwrite the earlier
   */
  name: string,
  /**
   * Determine whether the resolver supports the file
   */
  supports: (id: string) => void | boolean,
  /**
   * Transform source to declaration files
   *
   * Note that the path of the returns should base on `outDir`, or relative path to `root`
   */
  transform: (payload: {
    id: string,
    code: string,
    root: string,
    outDir: string,
    host: ts.CompilerHost,
    program: ts.Program
  }) => MaybePromise<{ path: string, content: string }[]>
}

export interface PluginOptions {
  /**
   * Specify root directory.
   *
   * Defaults to the 'root' of the Vite config, or `process.cwd()` if using Rollup.
   */
  root?: string,

  /**
   * Output directory for declaration files.
   *
   * Can be an array to output to multiple directories.
   *
   * Defaults to 'build.outDir' of the Vite config, or `outDir` of tsconfig.json if using Rollup.
   */
  outDir?: string | string[],

  /**
   * Override root path of entry files (useful in monorepos).
   *
   * The output path of each file will be calculated based on the value provided.
   *
   * The default is the smallest public path for all source files.
   */
  entryRoot?: string,

  /**
   * Restrict declaration files output to `outDir`.
   *
   * If true, generated declaration files outside `outDir` will be ignored.
   *
   * @default true
   */
  strictOutput?: boolean,

  /**
   * Override compilerOptions.
   *
   * @default null
   */
  compilerOptions?: ts.CompilerOptions | null,

  /**
   * Specify tsconfig.json path.
   *
   * Plugin resolves `include` and `exclude` globs from tsconfig.json.
   *
   * If not specified, plugin will find config file from root.
   */
  tsconfigPath?: string,

  /**
   * Specify custom resolvers.
   *
   * @default []
   */
  resolvers?: Resolver[],

  /**
   * Parsing `paths` of tsconfig.json to aliases.
   *
   * Note that these aliases only use for declaration files.
   *
   * @default true
   * @remarks Only use first replacement of each path.
   */
  pathsToAliases?: boolean,

  /**
   * Set which paths should be excluded when transforming aliases.
   *
   * @default []
   */
  aliasesExclude?: (string | RegExp)[],

  /**
   * Whether to transform file names ending in '.vue.d.ts' to '.d.ts'.
   *
   * If there is a duplicate name after transform, it will fall back to the original name.
   *
   * @default false
   */
  cleanVueFileName?: boolean,

  /**
   * Whether to transform dynamic imports to static (eg `import('vue').DefineComponent` to `import { DefineComponent } from 'vue'`).
   *
   * Value is forced to `true` when `rollupTypes` is `true`.
   *
   * @default false
   */
  staticImport?: boolean,

  /**
   * Override `include` glob (relative to root).
   *
   * Defaults to `include` property of tsconfig.json (relative to tsconfig.json located).
   */
  include?: string | string[],

  /**
   * Override `exclude` glob.
   *
   * Defaults to `exclude` property of tsconfig.json or `'node_modules/**'` if not supplied.
   */
  exclude?: string | string[],

  /**
   * Whether to remove `import 'xxx'`.
   *
   * @default true
   */
  clearPureImport?: boolean,

  /**
   * Whether to generate types entry file(s).
   *
   * When `true`, uses package.json `types` property if it exists or `${outDir}/index.d.ts`.
   *
   * Value is forced to `true` when `rollupTypes` is `true`.
   *
   * @default false
   */
  insertTypesEntry?: boolean,

  /**
   * Rollup type declaration files after emitting them.
   *
   * Powered by `@microsoft/api-extractor` - time-intensive operation.
   *
   * @default false
   */
  rollupTypes?: boolean,

  /**
   * Bundled packages for `@microsoft/api-extractor`.
   *
   * @default []
   * @see https://api-extractor.com/pages/configs/api-extractor_json/#bundledpackages
   */
  bundledPackages?: string[],

  /**
   * Override the config of `@microsoft/api-extractor`.
   *
   * @default null
   * @see https://api-extractor.com/pages/setup/configure_api_report/
   */
  rollupConfig?: RollupConfig,

  /**
   * Override the invoke options of `@microsoft/api-extractor`.
   *
   * @default null
   * @see https://api-extractor.com/pages/setup/invoking/#invoking-from-a-build-script
   */
  rollupOptions?: IExtractorInvokeOptions,

  /**
   * Whether to copy .d.ts source files to `outDir`.
   *
   * @default false
   * @remarks Before 2.0, the default was `true`.
   */
  copyDtsFiles?: boolean,

  /**
   * Whether to emit declaration files only.
   *
   * When `true`, all the original outputs of vite (rollup) will be force removed.
   *
   * @default false
   */
  declarationOnly?: boolean,

  /**
   * Logging level for this plugin.
   *
   * Defaults to the 'logLevel' property of your Vite config.
   */
  logLevel?: LogLevel,

  /**
   * Hook called after diagnostic is emitted.
   *
   * According to the `diagnostics.length`, you can judge whether there is any type error.
   *
   * @default () => {}
   */
  afterDiagnostic?: (diagnostics: readonly ts.Diagnostic[]) => MaybePromise<void>,

  /**
   * Hook called prior to writing each declaration file.
   *
   * This allows you to transform the path or content.
   *
   * The file will be skipped when the return value `false` or `Promise<false>`.
   *
   * @default () => {}
   */
  beforeWriteFile?: (
    filePath: string,
    content: string
  ) => MaybePromise<
    | void
    | false
    | {
      filePath?: string,
      content?: string
    }
  >,

  /**
   * Hook called after rolling up declaration files.
   *
   * @default () => {}
   */
  afterRollup?: (result: ExtractorResult) => MaybePromise<void>,

  /**
   * Hook called after all declaration files are written.
   *
   * It will be received a map (path -> content) that records those emitted files.
   *
   * @default () => {}
   */
  afterBuild?: (emittedFiles: Map<string, string>) => MaybePromise<void>
}

Contributors

Thanks for all the contributions!

Example

Clone and run the following script:

pnpm run test:ts

Then check examples/ts/types.

Also Vue and React cases under examples.

A real project using this plugin: Vexip UI.

License

MIT License.