graphql - npm Package Compare versions

Comparing version 17.0.0-alpha.1.canary.pr.3658.null to 17.0.0-alpha.1.canary.pr.3659.5dba20aef36112d13569d5f296ef967383e60d0f

error/GraphQLError.d.ts

@@ -18,3 +18,3 @@ import type { Maybe } from '../jsutils/Maybe';
 export interface GraphQLErrorOptions {
-  nodes?: ReadonlyArray<ASTNode> | ASTNode | null;
+  nodes?: ReadonlyArray<ASTNode> | ASTNode | null | undefined;
   source?: Maybe<Source>;
@@ -21,0 +21,0 @@ positions?: Maybe<ReadonlyArray<number>>;

execution/collectFields.d.ts

@@ -9,2 +9,10 @@ import type { ObjMap } from '../jsutils/ObjMap';
 import type { GraphQLSchema } from '../type/schema';
+export interface PatchFields {
+  label: string | undefined;
+  fields: Map<string, ReadonlyArray<FieldNode>>;
+}
+export interface FieldsAndPatches {
+  fields: Map<string, ReadonlyArray<FieldNode>>;
+  patches: Array<PatchFields>;
+}
 /**
@@ -27,3 +35,3 @@ * Given a selectionSet, collects all of the fields and returns them.
   selectionSet: SelectionSetNode,
-): Map<string, ReadonlyArray<FieldNode>>;
+): FieldsAndPatches;
 /**
@@ -47,2 +55,2 @@ * Given an array of field nodes, collects all of the subfields of the passed
   fieldNodes: ReadonlyArray<FieldNode>,
-): Map<string, ReadonlyArray<FieldNode>>;
+): FieldsAndPatches;

execution/collectFields.js

@@ -5,2 +5,3 @@ import { AccumulatorMap } from '../jsutils/AccumulatorMap.js';
 import {
+  GraphQLDeferDirective,
   GraphQLIncludeDirective,
@@ -28,2 +29,3 @@ GraphQLSkipDirective,
   const fields = new AccumulatorMap();
+  const patches = [];
   collectFieldsImpl(
@@ -36,5 +38,6 @@ schema,
     fields,
+    patches,
     new Set(),
   );
-  return fields;
+  return { fields, patches };
 }
@@ -60,2 +63,7 @@ /**
   const visitedFragmentNames = new Set();
+  const subPatches = [];
+  const subFieldsAndPatches = {
+    fields: subFieldNodes,
+    patches: subPatches,
+  };
   for (const node of fieldNodes) {
@@ -70,2 +78,3 @@ if (node.selectionSet) {
         subFieldNodes,
+        subPatches,
         visitedFragmentNames,
@@ -75,3 +84,3 @@ );
   }
-  return subFieldNodes;
+  return subFieldsAndPatches;
 }
@@ -86,2 +95,3 @@ // eslint-disable-next-line max-params
   fields,
+  patches,
   visitedFragmentNames,
@@ -105,11 +115,31 @@ ) {
         }
-        collectFieldsImpl(
-          schema,
-          fragments,
-          variableValues,
-          runtimeType,
-          selection.selectionSet,
-          fields,
-          visitedFragmentNames,
-        );
+        const defer = getDeferValues(variableValues, selection);
+        if (defer) {
+          const patchFields = new AccumulatorMap();
+          collectFieldsImpl(
+            schema,
+            fragments,
+            variableValues,
+            runtimeType,
+            selection.selectionSet,
+            patchFields,
+            patches,
+            visitedFragmentNames,
+          );
+          patches.push({
+            label: defer.label,
+            fields: patchFields,
+          });
+        } else {
+          collectFieldsImpl(
+            schema,
+            fragments,
+            variableValues,
+            runtimeType,
+            selection.selectionSet,
+            fields,
+            patches,
+            visitedFragmentNames,
+          );
+        }
         break;
@@ -119,9 +149,9 @@ }
         const fragName = selection.name.value;
-        if (
-          visitedFragmentNames.has(fragName) ||
-          !shouldIncludeNode(variableValues, selection)
-        ) {
+        if (!shouldIncludeNode(variableValues, selection)) {
           continue;
         }
-        visitedFragmentNames.add(fragName);
+        const defer = getDeferValues(variableValues, selection);
+        if (visitedFragmentNames.has(fragName) && !defer) {
+          continue;
+        }
         const fragment = fragments[fragName];
@@ -134,11 +164,33 @@ if (
         }
-        collectFieldsImpl(
-          schema,
-          fragments,
-          variableValues,
-          runtimeType,
-          fragment.selectionSet,
-          fields,
-          visitedFragmentNames,
-        );
+        if (!defer) {
+          visitedFragmentNames.add(fragName);
+        }
+        if (defer) {
+          const patchFields = new AccumulatorMap();
+          collectFieldsImpl(
+            schema,
+            fragments,
+            variableValues,
+            runtimeType,
+            fragment.selectionSet,
+            patchFields,
+            patches,
+            visitedFragmentNames,
+          );
+          patches.push({
+            label: defer.label,
+            fields: patchFields,
+          });
+        } else {
+          collectFieldsImpl(
+            schema,
+            fragments,
+            variableValues,
+            runtimeType,
+            fragment.selectionSet,
+            fields,
+            patches,
+            visitedFragmentNames,
+          );
+        }
         break;
@@ -150,2 +202,19 @@ }
 /**
+ * Returns an object containing the `@defer` arguments if a field should be
+ * deferred based on the experimental flag, defer directive present and
+ * not disabled by the "if" argument.
+ */
+function getDeferValues(variableValues, node) {
+  const defer = getDirectiveValues(GraphQLDeferDirective, node, variableValues);
+  if (!defer) {
+    return;
+  }
+  if (defer.if === false) {
+    return;
+  }
+  return {
+    label: typeof defer.label === 'string' ? defer.label : undefined,
+  };
+}
+/**
  * Determines if a field should be included based on the `@include` and `@skip`
@@ -152,0 +221,0 @@ * directives, where `@skip` has higher precedence than `@include`.

execution/execute.d.ts

@@ -59,2 +59,3 @@ import type { Maybe } from '../jsutils/Maybe';
   errors: Array<GraphQLError>;
+  subsequentPayloads: Set<AsyncPayloadRecord>;
 }
@@ -66,3 +67,5 @@ /**
  *   - `data` is the result of a successful execution of the query.
+ *   - `hasNext` is true if a future payload is expected.
  *   - `extensions` is reserved for adding non-standard properties.
+ *   - `incremental` is a list of the results from defer/stream directives.
  */
@@ -85,2 +88,95 @@ export interface ExecutionResult<
 }
+export declare type ExperimentalExecuteIncrementallyResults<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> =
+  | {
+      singleResult: ExecutionResult<TData, TExtensions>;
+    }
+  | {
+      initialResult: InitialIncrementalExecutionResult<TData, TExtensions>;
+      subsequentResults: AsyncGenerator<
+        SubsequentIncrementalExecutionResult<TData, TExtensions>,
+        void,
+        void
+      >;
+    };
+export interface InitialIncrementalExecutionResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> extends ExecutionResult<TData, TExtensions> {
+  hasNext: boolean;
+  incremental?: ReadonlyArray<IncrementalResult<TData, TExtensions>>;
+  extensions?: TExtensions;
+}
+export interface FormattedInitialIncrementalExecutionResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> extends FormattedExecutionResult<TData, TExtensions> {
+  hasNext: boolean;
+  incremental?: ReadonlyArray<FormattedIncrementalResult<TData, TExtensions>>;
+  extensions?: TExtensions;
+}
+export interface SubsequentIncrementalExecutionResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> {
+  hasNext: boolean;
+  incremental?: ReadonlyArray<IncrementalResult<TData, TExtensions>>;
+  extensions?: TExtensions;
+}
+export interface FormattedSubsequentIncrementalExecutionResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> {
+  hasNext: boolean;
+  incremental?: ReadonlyArray<FormattedIncrementalResult<TData, TExtensions>>;
+  extensions?: TExtensions;
+}
+export interface IncrementalDeferResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> extends ExecutionResult<TData, TExtensions> {
+  path?: ReadonlyArray<string | number>;
+  label?: string;
+}
+export interface FormattedIncrementalDeferResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> extends FormattedExecutionResult<TData, TExtensions> {
+  path?: ReadonlyArray<string | number>;
+  label?: string;
+}
+export interface IncrementalStreamResult<
+  TData = Array<unknown>,
+  TExtensions = ObjMap<unknown>,
+> {
+  errors?: ReadonlyArray<GraphQLError>;
+  items?: TData | null;
+  path?: ReadonlyArray<string | number>;
+  label?: string;
+  extensions?: TExtensions;
+}
+export interface FormattedIncrementalStreamResult<
+  TData = Array<unknown>,
+  TExtensions = ObjMap<unknown>,
+> {
+  errors?: ReadonlyArray<GraphQLFormattedError>;
+  items?: TData | null;
+  path?: ReadonlyArray<string | number>;
+  label?: string;
+  extensions?: TExtensions;
+}
+export declare type IncrementalResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> =
+  | IncrementalDeferResult<TData, TExtensions>
+  | IncrementalStreamResult<TData, TExtensions>;
+export declare type FormattedIncrementalResult<
+  TData = ObjMap<unknown>,
+  TExtensions = ObjMap<unknown>,
+> =
+  | FormattedIncrementalDeferResult<TData, TExtensions>
+  | FormattedIncrementalStreamResult<TData, TExtensions>;
 export interface ExecutionArgs {
@@ -108,2 +204,8 @@ schema: GraphQLSchema;
  * a GraphQLError will be thrown immediately explaining the invalid input.
+ *
+ * This function does not support incremental delivery (`@defer` and `@stream`).
+ * If an operation which would defer or stream data is executed with this
+ * function, it will throw or resolve to an object containing an error instead.
+ * Use `experimentalExecuteIncrementally` if you want to support incremental
+ * delivery.
  */
@@ -114,2 +216,17 @@ export declare function execute(
 /**
+ * Implements the "Executing requests" section of the GraphQL specification,
+ * including `@defer` and `@stream` as proposed in
+ * https://github.com/graphql/graphql-spec/pull/742
+ *
+ * This function returns a Promise of an ExperimentalExecuteIncrementallyResults
+ * object. This object either contains a single ExecutionResult as
+ * `singleResult`, or an `initialResult` and a stream of `subsequentResults`.
+ *
+ * If the arguments to this function do not result in a legal execution context,
+ * a GraphQLError will be thrown immediately explaining the invalid input.
+ */
+export declare function experimentalExecuteIncrementally(
+  args: ExecutionArgs,
+): PromiseOrValue<ExperimentalExecuteIncrementallyResults>;
+/**
  * Also implements the "Executing requests" section of the GraphQL specification.
@@ -173,7 +290,7 @@ * However, it guarantees to complete synchronously (or throw an error) assuming
  * If the client-provided arguments to this function do not result in a
- * compliant subscription, a GraphQL Response (ExecutionResult) with
- * descriptive errors and no data will be returned.
+ * compliant subscription, a GraphQL Response (ExecutionResult) with descriptive
+ * errors and no data will be returned.
  *
- * If the source stream could not be created due to faulty subscription
- * resolver logic or underlying systems, the promise will resolve to a single
+ * If the source stream could not be created due to faulty subscription resolver
+ * logic or underlying systems, the promise will resolve to a single
  * ExecutionResult containing `errors` and no `data`.
@@ -184,3 +301,11 @@ *
  *
- * Accepts either an object with named arguments, or individual arguments.
+ * This function does not support incremental delivery (`@defer` and `@stream`).
+ * If an operation which would defer or stream data is executed with this
+ * function, each `InitialIncrementalExecutionResult` and
+ * `SubsequentIncrementalExecutionResult` in the result stream will be replaced
+ * with an `ExecutionResult` with a single error stating that defer/stream is
+ * not supported.  Use `experimentalSubscribeIncrementally` if you want to
+ * support incremental delivery.
+ *
+ * Accepts an object with named arguments.
  */
@@ -193,2 +318,47 @@ export declare function subscribe(
 /**
+ * Implements the "Subscribe" algorithm described in the GraphQL specification,
+ * including `@defer` and `@stream` as proposed in
+ * https://github.com/graphql/graphql-spec/pull/742
+ *
+ * Returns a Promise which resolves to either an AsyncIterator (if successful)
+ * or an ExecutionResult (error). The promise will be rejected if the schema or
+ * other arguments to this function are invalid, or if the resolved event stream
+ * is not an async iterable.
+ *
+ * If the client-provided arguments to this function do not result in a
+ * compliant subscription, a GraphQL Response (ExecutionResult) with descriptive
+ * errors and no data will be returned.
+ *
+ * If the source stream could not be created due to faulty subscription resolver
+ * logic or underlying systems, the promise will resolve to a single
+ * ExecutionResult containing `errors` and no `data`.
+ *
+ * If the operation succeeded, the promise resolves to an AsyncIterator, which
+ * yields a stream of result representing the response stream.
+ *
+ * Each result may be an ExecutionResult with no `hasNext` (if executing the
+ * event did not use `@defer` or `@stream`), or an
+ * `InitialIncrementalExecutionResult` or `SubsequentIncrementalExecutionResult`
+ * (if executing the event used `@defer` or `@stream`). In the case of
+ * incremental execution results, each event produces a single
+ * `InitialIncrementalExecutionResult` followed by one or more
+ * `SubsequentIncrementalExecutionResult`s; all but the last have `hasNext: true`,
+ * and the last has `hasNext: false`. There is no interleaving between results
+ * generated from the same original event.
+ *
+ * Accepts an object with named arguments.
+ */
+export declare function experimentalSubscribeIncrementally(
+  args: ExecutionArgs,
+): PromiseOrValue<
+  | AsyncGenerator<
+      | ExecutionResult
+      | InitialIncrementalExecutionResult
+      | SubsequentIncrementalExecutionResult,
+      void,
+      void
+    >
+  | ExecutionResult
+>;
+/**
  * Implements the "CreateSourceEventStream" algorithm described in the
@@ -224,1 +394,45 @@ * GraphQL specification, resolving the subscription source event stream.
 ): PromiseOrValue<AsyncIterable<unknown> | ExecutionResult>;
+declare class DeferredFragmentRecord {
+  type: 'defer';
+  errors: Array<GraphQLError>;
+  label: string | undefined;
+  path: Path | undefined;
+  promise: Promise<void>;
+  data: ObjMap<unknown> | null;
+  parentContext: AsyncPayloadRecord | undefined;
+  isCompleted: boolean;
+  _exeContext: ExecutionContext;
+  _resolve?: (arg: PromiseOrValue<ObjMap<unknown> | null>) => void;
+  constructor(opts: {
+    label: string | undefined;
+    path: Path | undefined;
+    parentContext: AsyncPayloadRecord | undefined;
+    exeContext: ExecutionContext;
+  });
+  addData(data: PromiseOrValue<ObjMap<unknown> | null>): void;
+}
+declare class StreamRecord {
+  type: 'stream';
+  errors: Array<GraphQLError>;
+  label: string | undefined;
+  path: Path | undefined;
+  items: Array<unknown> | null;
+  promise: Promise<void>;
+  parentContext: AsyncPayloadRecord | undefined;
+  iterator: AsyncIterator<unknown> | undefined;
+  isCompletedIterator?: boolean;
+  isCompleted: boolean;
+  _exeContext: ExecutionContext;
+  _resolve?: (arg: PromiseOrValue<Array<unknown> | null>) => void;
+  constructor(opts: {
+    label: string | undefined;
+    path: Path | undefined;
+    iterator?: AsyncIterator<unknown>;
+    parentContext: AsyncPayloadRecord | undefined;
+    exeContext: ExecutionContext;
+  });
+  addItems(items: PromiseOrValue<Array<unknown> | null>): void;
+  setIsCompletedIterator(): void;
+}
+declare type AsyncPayloadRecord = DeferredFragmentRecord | StreamRecord;
+export {};

execution/execute.js

@@ -22,2 +22,3 @@ import { inspect } from '../jsutils/inspect.js';
 } from '../type/definition.js';
+import { GraphQLStreamDirective } from '../type/directives.js';
 import { assertValidSchema } from '../type/validate.js';
@@ -28,4 +29,9 @@ import {
 } from './collectFields.js';
-import { mapAsyncIterator } from './mapAsyncIterator.js';
-import { getArgumentValues, getVariableValues } from './values.js';
+import { flattenAsyncIterable } from './flattenAsyncIterable.js';
+import { mapAsyncIterable } from './mapAsyncIterable.js';
+import {
+  getArgumentValues,
+  getDirectiveValues,
+  getVariableValues,
+} from './values.js';
 /* eslint-disable max-params */
@@ -48,2 +54,4 @@ // This file contains a lot of such errors but we plan to refactor it anyway
 );
+const UNEXPECTED_MULTIPLE_PAYLOADS =
+  'Executing this GraphQL operation would unexpectedly produce multiple payloads (due to @defer or @stream directive)';
 /**
@@ -58,4 +66,39 @@ * Implements the "Executing requests" section of the GraphQL specification.
  * a GraphQLError will be thrown immediately explaining the invalid input.
+ *
+ * This function does not support incremental delivery (`@defer` and `@stream`).
+ * If an operation which would defer or stream data is executed with this
+ * function, it will throw or resolve to an object containing an error instead.
+ * Use `experimentalExecuteIncrementally` if you want to support incremental
+ * delivery.
  */
 export function execute(args) {
+  const result = experimentalExecuteIncrementally(args);
+  if (!isPromise(result)) {
+    if ('singleResult' in result) {
+      return result.singleResult;
+    }
+    throw new Error(UNEXPECTED_MULTIPLE_PAYLOADS);
+  }
+  return result.then((incrementalResult) => {
+    if ('singleResult' in incrementalResult) {
+      return incrementalResult.singleResult;
+    }
+    return {
+      errors: [new GraphQLError(UNEXPECTED_MULTIPLE_PAYLOADS)],
+    };
+  });
+}
+/**
+ * Implements the "Executing requests" section of the GraphQL specification,
+ * including `@defer` and `@stream` as proposed in
+ * https://github.com/graphql/graphql-spec/pull/742
+ *
+ * This function returns a Promise of an ExperimentalExecuteIncrementallyResults
+ * object. This object either contains a single ExecutionResult as
+ * `singleResult`, or an `initialResult` and a stream of `subsequentResults`.
+ *
+ * If the arguments to this function do not result in a legal execution context,
+ * a GraphQLError will be thrown immediately explaining the invalid input.
+ */
+export function experimentalExecuteIncrementally(args) {
   // If a valid execution context cannot be created due to incorrect arguments,
@@ -66,3 +109,3 @@ // a "Response" with only errors is returned.
   if (!('schema' in exeContext)) {
-    return { errors: exeContext };
+    return { singleResult: { errors: exeContext } };
   }
@@ -87,13 +130,35 @@ return executeImpl(exeContext);
       return result.then(
-        (data) => buildResponse(data, exeContext.errors),
+        (data) => {
+          const initialResult = buildResponse(data, exeContext.errors);
+          if (exeContext.subsequentPayloads.size > 0) {
+            return {
+              initialResult: {
+                ...initialResult,
+                hasNext: true,
+              },
+              subsequentResults: yieldSubsequentPayloads(exeContext),
+            };
+          }
+          return { singleResult: initialResult };
+        },
         (error) => {
           exeContext.errors.push(error);
-          return buildResponse(null, exeContext.errors);
+          return { singleResult: buildResponse(null, exeContext.errors) };
         },
       );
     }
-    return buildResponse(result, exeContext.errors);
+    const initialResult = buildResponse(result, exeContext.errors);
+    if (exeContext.subsequentPayloads.size > 0) {
+      return {
+        initialResult: {
+          ...initialResult,
+          hasNext: true,
+        },
+        subsequentResults: yieldSubsequentPayloads(exeContext),
+      };
+    }
+    return { singleResult: initialResult };
   } catch (error) {
     exeContext.errors.push(error);
-    return buildResponse(null, exeContext.errors);
+    return { singleResult: buildResponse(null, exeContext.errors) };
   }
@@ -107,8 +172,8 @@ }
 export function executeSync(args) {
-  const result = execute(args);
+  const result = experimentalExecuteIncrementally(args);
   // Assert that the execution was synchronous.
-  if (isPromise(result)) {
+  if (isPromise(result) || 'initialResult' in result) {
     throw new Error('GraphQL execution failed to complete synchronously.');
   }
-  return result;
+  return result.singleResult;
 }
@@ -198,2 +263,3 @@ /**
     subscribeFieldResolver: subscribeFieldResolver ?? defaultFieldResolver,
+    subsequentPayloads: new Set(),
     errors: [],
@@ -222,3 +288,3 @@ };
   }
-  const rootFields = collectFields(
+  const { fields: rootFields, patches } = collectFields(
     schema,
@@ -231,7 +297,9 @@ fragments,
   const path = undefined;
+  let result;
   switch (operation.operation) {
     case OperationTypeNode.QUERY:
-      return executeFields(exeContext, rootType, rootValue, path, rootFields);
+      result = executeFields(exeContext, rootType, rootValue, path, rootFields);
+      break;
     case OperationTypeNode.MUTATION:
-      return executeFieldsSerially(
+      result = executeFieldsSerially(
         exeContext,
@@ -243,7 +311,20 @@ rootType,
       );
+      break;
     case OperationTypeNode.SUBSCRIPTION:
       // TODO: deprecate `subscribe` and move all logic here
       // Temporary solution until we finish merging execute and subscribe together
-      return executeFields(exeContext, rootType, rootValue, path, rootFields);
+      result = executeFields(exeContext, rootType, rootValue, path, rootFields);
   }
+  for (const patch of patches) {
+    const { label, fields: patchFields } = patch;
+    executeDeferredFragment(
+      exeContext,
+      rootType,
+      rootValue,
+      patchFields,
+      label,
+      path,
+    );
+  }
+  return result;
 }
@@ -262,3 +343,3 @@ /**
   return promiseReduce(
-    fields.entries(),
+    fields,
     (results, [responseName, fieldNodes]) => {
@@ -292,6 +373,13 @@ const fieldPath = addPath(path, responseName, parentType.name);
  */
-function executeFields(exeContext, parentType, sourceValue, path, fields) {
+function executeFields(
+  exeContext,
+  parentType,
+  sourceValue,
+  path,
+  fields,
+  asyncPayloadRecord,
+) {
   const results = Object.create(null);
   let containsPromise = false;
-  for (const [responseName, fieldNodes] of fields.entries()) {
+  for (const [responseName, fieldNodes] of fields) {
     const fieldPath = addPath(path, responseName, parentType.name);
@@ -304,2 +392,3 @@ const result = executeField(
       fieldPath,
+      asyncPayloadRecord,
     );
@@ -328,3 +417,11 @@ if (result !== undefined) {
  */
-function executeField(exeContext, parentType, source, fieldNodes, path) {
+function executeField(
+  exeContext,
+  parentType,
+  source,
+  fieldNodes,
+  path,
+  asyncPayloadRecord,
+) {
+  const errors = asyncPayloadRecord?.errors ?? exeContext.errors;
   const fieldName = fieldNodes[0].name.value;
@@ -362,3 +459,11 @@ const fieldDef = exeContext.schema.getField(parentType, fieldName);
       completed = result.then((resolved) =>
-        completeValue(exeContext, returnType, fieldNodes, info, path, resolved),
+        completeValue(
+          exeContext,
+          returnType,
+          fieldNodes,
+          info,
+          path,
+          resolved,
+          asyncPayloadRecord,
+        ),
       );
@@ -373,2 +478,3 @@ } else {
         result,
+        asyncPayloadRecord,
       );
@@ -381,3 +487,3 @@ }
         const error = locatedError(rawError, fieldNodes, pathToArray(path));
-        return handleFieldError(error, returnType, exeContext);
+        return handleFieldError(error, returnType, errors);
       });
@@ -388,3 +494,3 @@ }
     const error = locatedError(rawError, fieldNodes, pathToArray(path));
-    return handleFieldError(error, returnType, exeContext);
+    return handleFieldError(error, returnType, errors);
   }
@@ -418,3 +524,3 @@ }
 }
-function handleFieldError(error, returnType, exeContext) {
+function handleFieldError(error, returnType, errors) {
   // If the field type is non-nullable, then it is resolved without any
@@ -427,3 +533,3 @@ // protection from errors, however it still properly locates the error.
   // a null value for this field if one is encountered.
-  exeContext.errors.push(error);
+  errors.push(error);
   return null;
@@ -452,3 +558,11 @@ }
  */
-function completeValue(exeContext, returnType, fieldNodes, info, path, result) {
+function completeValue(
+  exeContext,
+  returnType,
+  fieldNodes,
+  info,
+  path,
+  result,
+  asyncPayloadRecord,
+) {
   // If result is an Error, throw a located error.
@@ -468,2 +582,3 @@ if (result instanceof Error) {
       result,
+      asyncPayloadRecord,
     );
@@ -490,2 +605,3 @@ if (completed === null) {
       result,
+      asyncPayloadRecord,
     );
@@ -508,2 +624,3 @@ }
       result,
+      asyncPayloadRecord,
     );
@@ -520,2 +637,3 @@ }
       result,
+      asyncPayloadRecord,
     );
@@ -532,2 +650,114 @@ }
 /**
+ * Returns an object containing the `@stream` arguments if a field should be
+ * streamed based on the experimental flag, stream directive present and
+ * not disabled by the "if" argument.
+ */
+function getStreamValues(exeContext, fieldNodes, path) {
+  // do not stream inner lists of multi-dimensional lists
+  if (typeof path.key === 'number') {
+    return;
+  }
+  // validation only allows equivalent streams on multiple fields, so it is
+  // safe to only check the first fieldNode for the stream directive
+  const stream = getDirectiveValues(
+    GraphQLStreamDirective,
+    fieldNodes[0],
+    exeContext.variableValues,
+  );
+  if (!stream) {
+    return;
+  }
+  if (stream.if === false) {
+    return;
+  }
+  typeof stream.initialCount === 'number' ||
+    invariant(false, 'initialCount must be a number');
+  stream.initialCount >= 0 ||
+    invariant(false, 'initialCount must be a positive integer');
+  return {
+    initialCount: stream.initialCount,
+    label: typeof stream.label === 'string' ? stream.label : undefined,
+  };
+}
+/**
+ * Complete a async iterator value by completing the result and calling
+ * recursively until all the results are completed.
+ */
+async function completeAsyncIteratorValue(
+  exeContext,
+  itemType,
+  fieldNodes,
+  info,
+  path,
+  iterator,
+  asyncPayloadRecord,
+) {
+  const errors = asyncPayloadRecord?.errors ?? exeContext.errors;
+  const stream = getStreamValues(exeContext, fieldNodes, path);
+  let containsPromise = false;
+  const completedResults = [];
+  let index = 0;
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    if (
+      stream &&
+      typeof stream.initialCount === 'number' &&
+      index >= stream.initialCount
+    ) {
+      // eslint-disable-next-line @typescript-eslint/no-floating-promises
+      executeStreamIterator(
+        index,
+        iterator,
+        exeContext,
+        fieldNodes,
+        info,
+        itemType,
+        path,
+        stream.label,
+        asyncPayloadRecord,
+      );
+      break;
+    }
+    const fieldPath = addPath(path, index, undefined);
+    try {
+      // eslint-disable-next-line no-await-in-loop
+      const { value, done } = await iterator.next();
+      if (done) {
+        break;
+      }
+      try {
+        // TODO can the error checking logic be consolidated with completeListValue?
+        const completedItem = completeValue(
+          exeContext,
+          itemType,
+          fieldNodes,
+          info,
+          fieldPath,
+          value,
+          asyncPayloadRecord,
+        );
+        if (isPromise(completedItem)) {
+          containsPromise = true;
+        }
+        completedResults.push(completedItem);
+      } catch (rawError) {
+        completedResults.push(null);
+        const error = locatedError(
+          rawError,
+          fieldNodes,
+          pathToArray(fieldPath),
+        );
+        handleFieldError(error, itemType, errors);
+      }
+    } catch (rawError) {
+      completedResults.push(null);
+      const error = locatedError(rawError, fieldNodes, pathToArray(fieldPath));
+      handleFieldError(error, itemType, errors);
+      break;
+    }
+    index += 1;
+  }
+  return containsPromise ? Promise.all(completedResults) : completedResults;
+}
+/**
  * Complete a list value by completing each item in the list with the
@@ -543,3 +773,18 @@ * inner type
   result,
+  asyncPayloadRecord,
 ) {
+  const itemType = returnType.ofType;
+  const errors = asyncPayloadRecord?.errors ?? exeContext.errors;
+  if (isAsyncIterable(result)) {
+    const iterator = result[Symbol.asyncIterator]();
+    return completeAsyncIteratorValue(
+      exeContext,
+      itemType,
+      fieldNodes,
+      info,
+      path,
+      iterator,
+      asyncPayloadRecord,
+    );
+  }
   if (!isIterableObject(result)) {
@@ -550,7 +795,10 @@ throw new GraphQLError(
   }
+  const stream = getStreamValues(exeContext, fieldNodes, path);
   // This is specified as a simple map, however we're optimizing the path
   // where the list contains no Promises by avoiding creating another Promise.
-  const itemType = returnType.ofType;
   let containsPromise = false;
-  const completedResults = Array.from(result, (item, index) => {
+  let previousAsyncPayloadRecord = asyncPayloadRecord;
+  const completedResults = [];
+  let index = 0;
+  for (const item of result) {
     // No need to modify the info object containing the path,
@@ -561,2 +809,20 @@ // since from here on it is not ever accessed by resolver functions.
       let completedItem;
+      if (
+        stream &&
+        typeof stream.initialCount === 'number' &&
+        index >= stream.initialCount
+      ) {
+        previousAsyncPayloadRecord = executeStreamField(
+          itemPath,
+          item,
+          exeContext,
+          fieldNodes,
+          info,
+          itemType,
+          stream.label,
+          previousAsyncPayloadRecord,
+        );
+        index++;
+        continue;
+      }
       if (isPromise(item)) {
@@ -571,2 +837,3 @@ completedItem = item.then((resolved) =>
             resolved,
+            asyncPayloadRecord,
           ),
@@ -582,2 +849,3 @@ );
           item,
+          asyncPayloadRecord,
         );
@@ -589,17 +857,21 @@ }
         // to take a second callback for the error case.
-        return completedItem.then(undefined, (rawError) => {
-          const error = locatedError(
-            rawError,
-            fieldNodes,
-            pathToArray(itemPath),
-          );
-          return handleFieldError(error, itemType, exeContext);
-        });
+        completedResults.push(
+          completedItem.then(undefined, (rawError) => {
+            const error = locatedError(
+              rawError,
+              fieldNodes,
+              pathToArray(itemPath),
+            );
+            return handleFieldError(error, itemType, errors);
+          }),
+        );
+      } else {
+        completedResults.push(completedItem);
       }
-      return completedItem;
     } catch (rawError) {
       const error = locatedError(rawError, fieldNodes, pathToArray(itemPath));
-      return handleFieldError(error, itemType, exeContext);
+      completedResults.push(handleFieldError(error, itemType, errors));
     }
-  });
+    index++;
+  }
   return containsPromise ? Promise.all(completedResults) : completedResults;
@@ -632,2 +904,3 @@ }
   result,
+  asyncPayloadRecord,
 ) {
@@ -653,2 +926,3 @@ const resolveTypeFn = returnType.resolveType ?? exeContext.typeResolver;
         result,
+        asyncPayloadRecord,
       ),
@@ -671,2 +945,3 @@ );
     result,
+    asyncPayloadRecord,
   );
@@ -732,5 +1007,4 @@ }
   result,
+  asyncPayloadRecord,
 ) {
-  // Collect sub-fields to execute to complete this value.
-  const subFieldNodes = collectSubfields(exeContext, returnType, fieldNodes);
   // If there is an isTypeOf predicate function, call it with the
@@ -746,8 +1020,9 @@ // current result. If isTypeOf returns false, then raise an error rather
         }
-        return executeFields(
+        return collectAndExecuteSubfields(
           exeContext,
           returnType,
+          fieldNodes,
+          path,
           result,
-          path,
-          subFieldNodes,
+          asyncPayloadRecord,
         );
@@ -760,3 +1035,10 @@ });
   }
-  return executeFields(exeContext, returnType, result, path, subFieldNodes);
+  return collectAndExecuteSubfields(
+    exeContext,
+    returnType,
+    fieldNodes,
+    path,
+    result,
+    asyncPayloadRecord,
+  );
 }
@@ -769,2 +1051,38 @@ function invalidReturnTypeError(returnType, result, fieldNodes) {
 }
+function collectAndExecuteSubfields(
+  exeContext,
+  returnType,
+  fieldNodes,
+  path,
+  result,
+  asyncPayloadRecord,
+) {
+  // Collect sub-fields to execute to complete this value.
+  const { fields: subFieldNodes, patches: subPatches } = collectSubfields(
+    exeContext,
+    returnType,
+    fieldNodes,
+  );
+  const subFields = executeFields(
+    exeContext,
+    returnType,
+    result,
+    path,
+    subFieldNodes,
+    asyncPayloadRecord,
+  );
+  for (const subPatch of subPatches) {
+    const { label, fields: subPatchFieldNodes } = subPatch;
+    executeDeferredFragment(
+      exeContext,
+      returnType,
+      result,
+      subPatchFieldNodes,
+      label,
+      path,
+      asyncPayloadRecord,
+    );
+  }
+  return subFields;
+}
 /**
@@ -844,7 +1162,7 @@ * If a resolveType function is not given, then a default resolve behavior is
  * If the client-provided arguments to this function do not result in a
- * compliant subscription, a GraphQL Response (ExecutionResult) with
- * descriptive errors and no data will be returned.
+ * compliant subscription, a GraphQL Response (ExecutionResult) with descriptive
+ * errors and no data will be returned.
  *
- * If the source stream could not be created due to faulty subscription
- * resolver logic or underlying systems, the promise will resolve to a single
+ * If the source stream could not be created due to faulty subscription resolver
+ * logic or underlying systems, the promise will resolve to a single
  * ExecutionResult containing `errors` and no `data`.
@@ -855,5 +1173,67 @@ *
  *
- * Accepts either an object with named arguments, or individual arguments.
+ * This function does not support incremental delivery (`@defer` and `@stream`).
+ * If an operation which would defer or stream data is executed with this
+ * function, each `InitialIncrementalExecutionResult` and
+ * `SubsequentIncrementalExecutionResult` in the result stream will be replaced
+ * with an `ExecutionResult` with a single error stating that defer/stream is
+ * not supported.  Use `experimentalSubscribeIncrementally` if you want to
+ * support incremental delivery.
+ *
+ * Accepts an object with named arguments.
  */
 export function subscribe(args) {
+  const maybePromise = experimentalSubscribeIncrementally(args);
+  if (isPromise(maybePromise)) {
+    return maybePromise.then((resultOrIterable) =>
+      isAsyncIterable(resultOrIterable)
+        ? mapAsyncIterable(resultOrIterable, ensureSingleExecutionResult)
+        : resultOrIterable,
+    );
+  }
+  return isAsyncIterable(maybePromise)
+    ? mapAsyncIterable(maybePromise, ensureSingleExecutionResult)
+    : maybePromise;
+}
+function ensureSingleExecutionResult(result) {
+  if ('hasNext' in result) {
+    return {
+      errors: [new GraphQLError(UNEXPECTED_MULTIPLE_PAYLOADS)],
+    };
+  }
+  return result;
+}
+/**
+ * Implements the "Subscribe" algorithm described in the GraphQL specification,
+ * including `@defer` and `@stream` as proposed in
+ * https://github.com/graphql/graphql-spec/pull/742
+ *
+ * Returns a Promise which resolves to either an AsyncIterator (if successful)
+ * or an ExecutionResult (error). The promise will be rejected if the schema or
+ * other arguments to this function are invalid, or if the resolved event stream
+ * is not an async iterable.
+ *
+ * If the client-provided arguments to this function do not result in a
+ * compliant subscription, a GraphQL Response (ExecutionResult) with descriptive
+ * errors and no data will be returned.
+ *
+ * If the source stream could not be created due to faulty subscription resolver
+ * logic or underlying systems, the promise will resolve to a single
+ * ExecutionResult containing `errors` and no `data`.
+ *
+ * If the operation succeeded, the promise resolves to an AsyncIterator, which
+ * yields a stream of result representing the response stream.
+ *
+ * Each result may be an ExecutionResult with no `hasNext` (if executing the
+ * event did not use `@defer` or `@stream`), or an
+ * `InitialIncrementalExecutionResult` or `SubsequentIncrementalExecutionResult`
+ * (if executing the event used `@defer` or `@stream`). In the case of
+ * incremental execution results, each event produces a single
+ * `InitialIncrementalExecutionResult` followed by one or more
+ * `SubsequentIncrementalExecutionResult`s; all but the last have `hasNext: true`,
+ * and the last has `hasNext: false`. There is no interleaving between results
+ * generated from the same original event.
+ *
+ * Accepts an object with named arguments.
+ */
+export function experimentalSubscribeIncrementally(args) {
   // If a valid execution context cannot be created due to incorrect arguments,
@@ -874,2 +1254,10 @@ // a "Response" with only errors is returned.
 }
+async function* ensureAsyncIterable(someExecutionResult) {
+  if ('initialResult' in someExecutionResult) {
+    yield someExecutionResult.initialResult;
+    yield* someExecutionResult.subsequentResults;
+  } else {
+    yield someExecutionResult.singleResult;
+  }
+}
 function mapSourceToResponse(exeContext, resultOrStream) {
@@ -885,4 +1273,8 @@ if (!isAsyncIterable(resultOrStream)) {
   // "ExecuteQuery" algorithm, for which `execute` is also used.
-  return mapAsyncIterator(resultOrStream, (payload) =>
-    executeImpl(buildPerEventExecutionContext(exeContext, payload)),
+  return flattenAsyncIterable(
+    mapAsyncIterable(resultOrStream, async (payload) =>
+      ensureAsyncIterable(
+        await executeImpl(buildPerEventExecutionContext(exeContext, payload)),
+      ),
+    ),
   );
@@ -949,3 +1341,3 @@ }
   }
-  const rootFields = collectFields(
+  const { fields: rootFields } = collectFields(
     schema,
@@ -957,3 +1349,4 @@ fragments,
   );
-  const [responseName, fieldNodes] = [...rootFields.entries()][0];
+  const firstRootField = rootFields.entries().next().value;
+  const [responseName, fieldNodes] = firstRootField;
   const fieldName = fieldNodes[0].name.value;
@@ -1012,1 +1405,383 @@ const fieldDef = schema.getField(rootType, fieldName);
 }
+function executeDeferredFragment(
+  exeContext,
+  parentType,
+  sourceValue,
+  fields,
+  label,
+  path,
+  parentContext,
+) {
+  const asyncPayloadRecord = new DeferredFragmentRecord({
+    label,
+    path,
+    parentContext,
+    exeContext,
+  });
+  let promiseOrData;
+  try {
+    promiseOrData = executeFields(
+      exeContext,
+      parentType,
+      sourceValue,
+      path,
+      fields,
+      asyncPayloadRecord,
+    );
+    if (isPromise(promiseOrData)) {
+      promiseOrData = promiseOrData.then(null, (e) => {
+        asyncPayloadRecord.errors.push(e);
+        return null;
+      });
+    }
+  } catch (e) {
+    asyncPayloadRecord.errors.push(e);
+    promiseOrData = null;
+  }
+  asyncPayloadRecord.addData(promiseOrData);
+}
+function executeStreamField(
+  path,
+  item,
+  exeContext,
+  fieldNodes,
+  info,
+  itemType,
+  label,
+  parentContext,
+) {
+  const asyncPayloadRecord = new StreamRecord({
+    label,
+    path,
+    parentContext,
+    exeContext,
+  });
+  let completedItem;
+  let completedItems;
+  try {
+    try {
+      if (isPromise(item)) {
+        completedItem = item.then((resolved) =>
+          completeValue(
+            exeContext,
+            itemType,
+            fieldNodes,
+            info,
+            path,
+            resolved,
+            asyncPayloadRecord,
+          ),
+        );
+      } else {
+        completedItem = completeValue(
+          exeContext,
+          itemType,
+          fieldNodes,
+          info,
+          path,
+          item,
+          asyncPayloadRecord,
+        );
+      }
+      if (isPromise(completedItem)) {
+        // Note: we don't rely on a `catch` method, but we do expect "thenable"
+        // to take a second callback for the error case.
+        completedItem = completedItem.then(undefined, (rawError) => {
+          const error = locatedError(rawError, fieldNodes, pathToArray(path));
+          return handleFieldError(error, itemType, asyncPayloadRecord.errors);
+        });
+      }
+    } catch (rawError) {
+      const error = locatedError(rawError, fieldNodes, pathToArray(path));
+      completedItems = handleFieldError(
+        error,
+        itemType,
+        asyncPayloadRecord.errors,
+      );
+    }
+  } catch (error) {
+    asyncPayloadRecord.errors.push(error);
+    asyncPayloadRecord.addItems(null);
+    return asyncPayloadRecord;
+  }
+  if (isPromise(completedItem)) {
+    completedItems = completedItem.then(
+      (value) => [value],
+      (error) => {
+        asyncPayloadRecord.errors.push(error);
+        return null;
+      },
+    );
+  } else {
+    completedItems = [completedItem];
+  }
+  asyncPayloadRecord.addItems(completedItems);
+  return asyncPayloadRecord;
+}
+async function executeStreamIteratorItem(
+  iterator,
+  exeContext,
+  fieldNodes,
+  info,
+  itemType,
+  asyncPayloadRecord,
+  fieldPath,
+) {
+  let item;
+  try {
+    const { value, done } = await iterator.next();
+    if (done) {
+      asyncPayloadRecord.setIsCompletedIterator();
+      return { done, value: undefined };
+    }
+    item = value;
+  } catch (rawError) {
+    const error = locatedError(rawError, fieldNodes, pathToArray(fieldPath));
+    const value = handleFieldError(error, itemType, asyncPayloadRecord.errors);
+    // don't continue if iterator throws
+    return { done: true, value };
+  }
+  let completedItem;
+  try {
+    completedItem = completeValue(
+      exeContext,
+      itemType,
+      fieldNodes,
+      info,
+      fieldPath,
+      item,
+      asyncPayloadRecord,
+    );
+    if (isPromise(completedItem)) {
+      completedItem = completedItem.then(undefined, (rawError) => {
+        const error = locatedError(
+          rawError,
+          fieldNodes,
+          pathToArray(fieldPath),
+        );
+        return handleFieldError(error, itemType, asyncPayloadRecord.errors);
+      });
+    }
+    return { done: false, value: completedItem };
+  } catch (rawError) {
+    const error = locatedError(rawError, fieldNodes, pathToArray(fieldPath));
+    const value = handleFieldError(error, itemType, asyncPayloadRecord.errors);
+    return { done: false, value };
+  }
+}
+async function executeStreamIterator(
+  initialIndex,
+  iterator,
+  exeContext,
+  fieldNodes,
+  info,
+  itemType,
+  path,
+  label,
+  parentContext,
+) {
+  let index = initialIndex;
+  let previousAsyncPayloadRecord = parentContext ?? undefined;
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const fieldPath = addPath(path, index, undefined);
+    const asyncPayloadRecord = new StreamRecord({
+      label,
+      path: fieldPath,
+      parentContext: previousAsyncPayloadRecord,
+      iterator,
+      exeContext,
+    });
+    const dataPromise = executeStreamIteratorItem(
+      iterator,
+      exeContext,
+      fieldNodes,
+      info,
+      itemType,
+      asyncPayloadRecord,
+      fieldPath,
+    );
+    asyncPayloadRecord.addItems(
+      dataPromise
+        .then(({ value }) => value)
+        .then(
+          (value) => [value],
+          (err) => {
+            asyncPayloadRecord.errors.push(err);
+            return null;
+          },
+        ),
+    );
+    try {
+      // eslint-disable-next-line no-await-in-loop
+      const { done } = await dataPromise;
+      if (done) {
+        break;
+      }
+    } catch (err) {
+      // do nothing, error is already handled above
+    }
+    previousAsyncPayloadRecord = asyncPayloadRecord;
+    index++;
+  }
+}
+function getCompletedIncrementalResults(exeContext) {
+  const incrementalResults = [];
+  for (const asyncPayloadRecord of exeContext.subsequentPayloads) {
+    const incrementalResult = {};
+    if (!asyncPayloadRecord.isCompleted) {
+      continue;
+    }
+    exeContext.subsequentPayloads.delete(asyncPayloadRecord);
+    if (isStreamPayload(asyncPayloadRecord)) {
+      const items = asyncPayloadRecord.items;
+      if (asyncPayloadRecord.isCompletedIterator) {
+        // async iterable resolver just finished but there may be pending payloads
+        continue;
+      }
+      incrementalResult.items = items;
+    } else {
+      const data = asyncPayloadRecord.data;
+      incrementalResult.data = data ?? null;
+    }
+    incrementalResult.path = asyncPayloadRecord.path
+      ? pathToArray(asyncPayloadRecord.path)
+      : [];
+    if (asyncPayloadRecord.label) {
+      incrementalResult.label = asyncPayloadRecord.label;
+    }
+    if (asyncPayloadRecord.errors.length > 0) {
+      incrementalResult.errors = asyncPayloadRecord.errors;
+    }
+    incrementalResults.push(incrementalResult);
+  }
+  return incrementalResults;
+}
+function yieldSubsequentPayloads(exeContext) {
+  let isDone = false;
+  async function next() {
+    if (isDone) {
+      return { value: undefined, done: true };
+    }
+    await Promise.race(
+      Array.from(exeContext.subsequentPayloads).map((p) => p.promise),
+    );
+    if (isDone) {
+      // a different call to next has exhausted all payloads
+      return { value: undefined, done: true };
+    }
+    const incremental = getCompletedIncrementalResults(exeContext);
+    const hasNext = exeContext.subsequentPayloads.size > 0;
+    if (!incremental.length && hasNext) {
+      return next();
+    }
+    if (!incremental.length && !hasNext) {
+      isDone = true;
+      return {
+        value: { hasNext },
+        done: false,
+      };
+    }
+    if (!hasNext) {
+      isDone = true;
+    }
+    return {
+      value: { incremental, hasNext },
+      done: false,
+    };
+  }
+  function returnStreamIterators() {
+    const promises = [];
+    exeContext.subsequentPayloads.forEach((asyncPayloadRecord) => {
+      if (
+        isStreamPayload(asyncPayloadRecord) &&
+        asyncPayloadRecord.iterator?.return
+      ) {
+        promises.push(asyncPayloadRecord.iterator.return());
+      }
+    });
+    return Promise.all(promises);
+  }
+  return {
+    [Symbol.asyncIterator]() {
+      return this;
+    },
+    next,
+    async return() {
+      await returnStreamIterators();
+      isDone = true;
+      return { value: undefined, done: true };
+    },
+    async throw(error) {
+      await returnStreamIterators();
+      isDone = true;
+      return Promise.reject(error);
+    },
+  };
+}
+class DeferredFragmentRecord {
+  constructor(opts) {
+    this.type = 'defer';
+    this.label = opts.label;
+    this.path = opts.path;
+    this.parentContext = opts.parentContext;
+    this.errors = [];
+    this._exeContext = opts.exeContext;
+    this._exeContext.subsequentPayloads.add(this);
+    this.isCompleted = false;
+    this.data = null;
+    this.promise = new Promise((resolve) => {
+      this._resolve = (promiseOrValue) => {
+        resolve(promiseOrValue);
+      };
+    }).then((data) => {
+      this.data = data;
+      this.isCompleted = true;
+    });
+  }
+  addData(data) {
+    const parentData = this.parentContext?.promise;
+    if (parentData) {
+      this._resolve?.(parentData.then(() => data));
+      return;
+    }
+    this._resolve?.(data);
+  }
+}
+class StreamRecord {
+  constructor(opts) {
+    this.type = 'stream';
+    this.items = null;
+    this.label = opts.label;
+    this.path = opts.path;
+    this.parentContext = opts.parentContext;
+    this.iterator = opts.iterator;
+    this.errors = [];
+    this._exeContext = opts.exeContext;
+    this._exeContext.subsequentPayloads.add(this);
+    this.isCompleted = false;
+    this.items = null;
+    this.promise = new Promise((resolve) => {
+      this._resolve = (promiseOrValue) => {
+        resolve(promiseOrValue);
+      };
+    }).then((items) => {
+      this.items = items;
+      this.isCompleted = true;
+    });
+  }
+  addItems(items) {
+    const parentData = this.parentContext?.promise;
+    if (parentData) {
+      this._resolve?.(parentData.then(() => items));
+      return;
+    }
+    this._resolve?.(items);
+  }
+  setIsCompletedIterator() {
+    this.isCompletedIterator = true;
+  }
+}
+function isStreamPayload(asyncPayload) {
+  return asyncPayload.type === 'stream';
+}

execution/index.d.ts

@@ -5,2 +5,3 @@ export { pathToArray as responsePathAsArray } from '../jsutils/Path';
   execute,
+  experimentalExecuteIncrementally,
   executeSync,
@@ -10,2 +11,3 @@ defaultFieldResolver,
   subscribe,
+  experimentalSubscribeIncrementally,
 } from './execute';
@@ -15,3 +17,14 @@ export type {
   ExecutionResult,
+  ExperimentalExecuteIncrementallyResults,
+  InitialIncrementalExecutionResult,
+  SubsequentIncrementalExecutionResult,
+  IncrementalDeferResult,
+  IncrementalStreamResult,
+  IncrementalResult,
   FormattedExecutionResult,
+  FormattedInitialIncrementalExecutionResult,
+  FormattedSubsequentIncrementalExecutionResult,
+  FormattedIncrementalDeferResult,
+  FormattedIncrementalStreamResult,
+  FormattedIncrementalResult,
 } from './execute';
@@ -18,0 +31,0 @@ export {

execution/index.js

@@ -5,2 +5,3 @@ export { pathToArray as responsePathAsArray } from '../jsutils/Path.js';
   execute,
+  experimentalExecuteIncrementally,
   executeSync,
@@ -10,2 +11,3 @@ defaultFieldResolver,
   subscribe,
+  experimentalSubscribeIncrementally,
 } from './execute.js';
@@ -12,0 +14,0 @@ export {

execution/values.d.ts

@@ -71,3 +71,3 @@ import type { Maybe } from '../jsutils/Maybe';
   node: {
-    readonly directives?: ReadonlyArray<DirectiveNode>;
+    readonly directives?: ReadonlyArray<DirectiveNode> | undefined;
   },
@@ -74,0 +74,0 @@ variableValues?: Maybe<ObjMap<unknown>>,

graphql.d.ts

@@ -18,2 +18,4 @@ import type { Maybe } from './jsutils/Maybe';
  *
+ * This function does not support incremental delivery (`@defer` and `@stream`).
+ *
  * Accepts either an object with named arguments, or individual arguments:
@@ -20,0 +22,0 @@ *

index.d.ts

@@ -55,2 +55,4 @@ /**
   GraphQLSkipDirective,
+  GraphQLDeferDirective,
+  GraphQLStreamDirective,
   GraphQLDeprecatedDirective,
@@ -205,2 +207,3 @@ GraphQLSpecifiedByDirective,
   isSelectionNode,
+  isNullabilityAssertionNode,
   isValueNode,
@@ -233,2 +236,6 @@ isConstValueNode,
   ArgumentNode,
+  NullabilityAssertionNode,
+  NonNullAssertionNode,
+  ErrorBoundaryNode,
+  ListNullabilityOperatorNode,
   ConstArgumentNode,
@@ -284,2 +291,3 @@ FragmentSpreadNode,
   execute,
+  experimentalExecuteIncrementally,
   executeSync,
@@ -293,2 +301,3 @@ defaultFieldResolver,
   subscribe,
+  experimentalSubscribeIncrementally,
   createSourceEventStream,
@@ -299,3 +308,14 @@ } from './execution/index';
   ExecutionResult,
+  ExperimentalExecuteIncrementallyResults,
+  InitialIncrementalExecutionResult,
+  SubsequentIncrementalExecutionResult,
+  IncrementalDeferResult,
+  IncrementalStreamResult,
+  IncrementalResult,
   FormattedExecutionResult,
+  FormattedInitialIncrementalExecutionResult,
+  FormattedSubsequentIncrementalExecutionResult,
+  FormattedIncrementalDeferResult,
+  FormattedIncrementalStreamResult,
+  FormattedIncrementalResult,
 } from './execution/index';
@@ -302,0 +322,0 @@ export {

index.js

@@ -60,2 +60,4 @@ /**
   GraphQLSkipDirective,
+  GraphQLDeferDirective,
+  GraphQLStreamDirective,
   GraphQLDeprecatedDirective,
@@ -167,2 +169,3 @@ GraphQLSpecifiedByDirective,
   isSelectionNode,
+  isNullabilityAssertionNode,
   isValueNode,
@@ -179,2 +182,3 @@ isConstValueNode,
   execute,
+  experimentalExecuteIncrementally,
   executeSync,
@@ -188,2 +192,3 @@ defaultFieldResolver,
   subscribe,
+  experimentalSubscribeIncrementally,
   createSourceEventStream,
@@ -190,0 +195,0 @@ } from './execution/index.js';

jsutils/promiseForObject.js

@@ -9,6 +9,8 @@ /**
 export function promiseForObject(object) {
-  return Promise.all(Object.values(object)).then((resolvedValues) => {
+  const keys = Object.keys(object);
+  const values = Object.values(object);
+  return Promise.all(values).then((resolvedValues) => {
     const resolvedObject = Object.create(null);
-    for (const [i, key] of Object.keys(object).entries()) {
-      resolvedObject[key] = resolvedValues[i];
+    for (let i = 0; i < keys.length; ++i) {
+      resolvedObject[keys[i]] = resolvedValues[i];
     }
@@ -15,0 +17,0 @@ return resolvedObject;

language/ast.d.ts

@@ -137,3 +137,6 @@ import type { Kind } from './kinds';
   | EnumTypeExtensionNode
-  | InputObjectTypeExtensionNode;
+  | InputObjectTypeExtensionNode
+  | NonNullAssertionNode
+  | ErrorBoundaryNode
+  | ListNullabilityOperatorNode;
 /**
@@ -158,3 +161,3 @@ * Utility type listing all nodes indexed by their kind.
   readonly kind: Kind.NAME;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly value: string;
@@ -165,3 +168,3 @@ }
   readonly kind: Kind.DOCUMENT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly definitions: ReadonlyArray<DefinitionNode>;
@@ -178,7 +181,9 @@ }
   readonly kind: Kind.OPERATION_DEFINITION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly operation: OperationTypeNode;
-  readonly name?: NameNode;
-  readonly variableDefinitions?: ReadonlyArray<VariableDefinitionNode>;
-  readonly directives?: ReadonlyArray<DirectiveNode>;
+  readonly name?: NameNode | undefined;
+  readonly variableDefinitions?:
+    | ReadonlyArray<VariableDefinitionNode>
+    | undefined;
+  readonly directives?: ReadonlyArray<DirectiveNode> | undefined;
   readonly selectionSet: SelectionSetNode;
@@ -193,11 +198,11 @@ }
   readonly kind: Kind.VARIABLE_DEFINITION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly variable: VariableNode;
   readonly type: TypeNode;
-  readonly defaultValue?: ConstValueNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly defaultValue?: ConstValueNode | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
 }
 export interface VariableNode {
   readonly kind: Kind.VARIABLE;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
@@ -207,3 +212,3 @@ }
   kind: Kind.SELECTION_SET;
-  loc?: Location;
+  loc?: Location | undefined;
   selections: ReadonlyArray<SelectionNode>;
@@ -217,12 +222,32 @@ }
   readonly kind: Kind.FIELD;
-  readonly loc?: Location;
-  readonly alias?: NameNode;
+  readonly loc?: Location | undefined;
+  readonly alias?: NameNode | undefined;
   readonly name: NameNode;
-  readonly arguments?: ReadonlyArray<ArgumentNode>;
-  readonly directives?: ReadonlyArray<DirectiveNode>;
-  readonly selectionSet?: SelectionSetNode;
+  readonly arguments?: ReadonlyArray<ArgumentNode> | undefined;
+  readonly nullabilityAssertion?: NullabilityAssertionNode | undefined;
+  readonly directives?: ReadonlyArray<DirectiveNode> | undefined;
+  readonly selectionSet?: SelectionSetNode | undefined;
 }
+export declare type NullabilityAssertionNode =
+  | NonNullAssertionNode
+  | ErrorBoundaryNode
+  | ListNullabilityOperatorNode;
+export interface ListNullabilityOperatorNode {
+  readonly kind: Kind.LIST_NULLABILITY_OPERATOR;
+  readonly loc?: Location | undefined;
+  readonly nullabilityAssertion?: NullabilityAssertionNode | undefined;
+}
+export interface NonNullAssertionNode {
+  readonly kind: Kind.NON_NULL_ASSERTION;
+  readonly loc?: Location | undefined;
+  readonly nullabilityAssertion?: ListNullabilityOperatorNode | undefined;
+}
+export interface ErrorBoundaryNode {
+  readonly kind: Kind.ERROR_BOUNDARY;
+  readonly loc?: Location | undefined;
+  readonly nullabilityAssertion?: ListNullabilityOperatorNode | undefined;
+}
 export interface ArgumentNode {
   readonly kind: Kind.ARGUMENT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
@@ -233,3 +258,3 @@ readonly value: ValueNode;
   readonly kind: Kind.ARGUMENT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
@@ -241,11 +266,11 @@ readonly value: ConstValueNode;
   readonly kind: Kind.FRAGMENT_SPREAD;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<DirectiveNode>;
+  readonly directives?: ReadonlyArray<DirectiveNode> | undefined;
 }
 export interface InlineFragmentNode {
   readonly kind: Kind.INLINE_FRAGMENT;
-  readonly loc?: Location;
-  readonly typeCondition?: NamedTypeNode;
-  readonly directives?: ReadonlyArray<DirectiveNode>;
+  readonly loc?: Location | undefined;
+  readonly typeCondition?: NamedTypeNode | undefined;
+  readonly directives?: ReadonlyArray<DirectiveNode> | undefined;
   readonly selectionSet: SelectionSetNode;
@@ -255,8 +280,10 @@ }
   readonly kind: Kind.FRAGMENT_DEFINITION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
   /** @deprecated variableDefinitions will be removed in v17.0.0 */
-  readonly variableDefinitions?: ReadonlyArray<VariableDefinitionNode>;
+  readonly variableDefinitions?:
+    | ReadonlyArray<VariableDefinitionNode>
+    | undefined;
   readonly typeCondition: NamedTypeNode;
-  readonly directives?: ReadonlyArray<DirectiveNode>;
+  readonly directives?: ReadonlyArray<DirectiveNode> | undefined;
   readonly selectionSet: SelectionSetNode;
@@ -286,3 +313,3 @@ }
   readonly kind: Kind.INT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly value: string;
@@ -292,3 +319,3 @@ }
   readonly kind: Kind.FLOAT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly value: string;
@@ -298,9 +325,9 @@ }
   readonly kind: Kind.STRING;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly value: string;
-  readonly block?: boolean;
+  readonly block?: boolean | undefined;
 }
 export interface BooleanValueNode {
   readonly kind: Kind.BOOLEAN;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly value: boolean;
@@ -310,7 +337,7 @@ }
   readonly kind: Kind.NULL;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
 }
 export interface EnumValueNode {
   readonly kind: Kind.ENUM;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly value: string;
@@ -320,3 +347,3 @@ }
   readonly kind: Kind.LIST;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly values: ReadonlyArray<ValueNode>;
@@ -326,3 +353,3 @@ }
   readonly kind: Kind.LIST;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly values: ReadonlyArray<ConstValueNode>;
@@ -332,3 +359,3 @@ }
   readonly kind: Kind.OBJECT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly fields: ReadonlyArray<ObjectFieldNode>;
@@ -338,3 +365,3 @@ }
   readonly kind: Kind.OBJECT;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly fields: ReadonlyArray<ConstObjectFieldNode>;
@@ -344,3 +371,3 @@ }
   readonly kind: Kind.OBJECT_FIELD;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
@@ -351,3 +378,3 @@ readonly value: ValueNode;
   readonly kind: Kind.OBJECT_FIELD;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
@@ -359,11 +386,11 @@ readonly value: ConstValueNode;
   readonly kind: Kind.DIRECTIVE;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly arguments?: ReadonlyArray<ArgumentNode>;
+  readonly arguments?: ReadonlyArray<ArgumentNode> | undefined;
 }
 export interface ConstDirectiveNode {
   readonly kind: Kind.DIRECTIVE;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly arguments?: ReadonlyArray<ConstArgumentNode>;
+  readonly arguments?: ReadonlyArray<ConstArgumentNode> | undefined;
 }
@@ -374,3 +401,3 @@ /** Type Reference */
   readonly kind: Kind.NAMED_TYPE;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
@@ -380,3 +407,3 @@ }
   readonly kind: Kind.LIST_TYPE;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly type: TypeNode;
@@ -386,3 +413,3 @@ }
   readonly kind: Kind.NON_NULL_TYPE;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly type: NamedTypeNode | ListTypeNode;
@@ -397,5 +424,5 @@ }
   readonly kind: Kind.SCHEMA_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
   readonly operationTypes: ReadonlyArray<OperationTypeDefinitionNode>;
@@ -405,3 +432,3 @@ }
   readonly kind: Kind.OPERATION_TYPE_DEFINITION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly operation: OperationTypeNode;
@@ -420,73 +447,73 @@ readonly type: NamedTypeNode;
   readonly kind: Kind.SCALAR_TYPE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
 }
 export interface ObjectTypeDefinitionNode {
   readonly kind: Kind.OBJECT_TYPE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly interfaces?: ReadonlyArray<NamedTypeNode>;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly fields?: ReadonlyArray<FieldDefinitionNode>;
+  readonly interfaces?: ReadonlyArray<NamedTypeNode> | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly fields?: ReadonlyArray<FieldDefinitionNode> | undefined;
 }
 export interface FieldDefinitionNode {
   readonly kind: Kind.FIELD_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly arguments?: ReadonlyArray<InputValueDefinitionNode>;
+  readonly arguments?: ReadonlyArray<InputValueDefinitionNode> | undefined;
   readonly type: TypeNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
 }
 export interface InputValueDefinitionNode {
   readonly kind: Kind.INPUT_VALUE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
   readonly type: TypeNode;
-  readonly defaultValue?: ConstValueNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly defaultValue?: ConstValueNode | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
 }
 export interface InterfaceTypeDefinitionNode {
   readonly kind: Kind.INTERFACE_TYPE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly interfaces?: ReadonlyArray<NamedTypeNode>;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly fields?: ReadonlyArray<FieldDefinitionNode>;
+  readonly interfaces?: ReadonlyArray<NamedTypeNode> | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly fields?: ReadonlyArray<FieldDefinitionNode> | undefined;
 }
 export interface UnionTypeDefinitionNode {
   readonly kind: Kind.UNION_TYPE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly types?: ReadonlyArray<NamedTypeNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly types?: ReadonlyArray<NamedTypeNode> | undefined;
 }
 export interface EnumTypeDefinitionNode {
   readonly kind: Kind.ENUM_TYPE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly values?: ReadonlyArray<EnumValueDefinitionNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly values?: ReadonlyArray<EnumValueDefinitionNode> | undefined;
 }
 export interface EnumValueDefinitionNode {
   readonly kind: Kind.ENUM_VALUE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
 }
 export interface InputObjectTypeDefinitionNode {
   readonly kind: Kind.INPUT_OBJECT_TYPE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly fields?: ReadonlyArray<InputValueDefinitionNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly fields?: ReadonlyArray<InputValueDefinitionNode> | undefined;
 }
@@ -496,6 +523,6 @@ /** Directive Definitions */
   readonly kind: Kind.DIRECTIVE_DEFINITION;
-  readonly loc?: Location;
-  readonly description?: StringValueNode;
+  readonly loc?: Location | undefined;
+  readonly description?: StringValueNode | undefined;
   readonly name: NameNode;
-  readonly arguments?: ReadonlyArray<InputValueDefinitionNode>;
+  readonly arguments?: ReadonlyArray<InputValueDefinitionNode> | undefined;
   readonly repeatable: boolean;
@@ -510,5 +537,7 @@ readonly locations: ReadonlyArray<NameNode>;
   readonly kind: Kind.SCHEMA_EXTENSION;
-  readonly loc?: Location;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly operationTypes?: ReadonlyArray<OperationTypeDefinitionNode>;
+  readonly loc?: Location | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly operationTypes?:
+    | ReadonlyArray<OperationTypeDefinitionNode>
+    | undefined;
 }
@@ -525,42 +554,42 @@ /** Type Extensions */
   readonly kind: Kind.SCALAR_TYPE_EXTENSION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
 }
 export interface ObjectTypeExtensionNode {
   readonly kind: Kind.OBJECT_TYPE_EXTENSION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly interfaces?: ReadonlyArray<NamedTypeNode>;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly fields?: ReadonlyArray<FieldDefinitionNode>;
+  readonly interfaces?: ReadonlyArray<NamedTypeNode> | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly fields?: ReadonlyArray<FieldDefinitionNode> | undefined;
 }
 export interface InterfaceTypeExtensionNode {
   readonly kind: Kind.INTERFACE_TYPE_EXTENSION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly interfaces?: ReadonlyArray<NamedTypeNode>;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly fields?: ReadonlyArray<FieldDefinitionNode>;
+  readonly interfaces?: ReadonlyArray<NamedTypeNode> | undefined;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly fields?: ReadonlyArray<FieldDefinitionNode> | undefined;
 }
 export interface UnionTypeExtensionNode {
   readonly kind: Kind.UNION_TYPE_EXTENSION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly types?: ReadonlyArray<NamedTypeNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly types?: ReadonlyArray<NamedTypeNode> | undefined;
 }
 export interface EnumTypeExtensionNode {
   readonly kind: Kind.ENUM_TYPE_EXTENSION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly values?: ReadonlyArray<EnumValueDefinitionNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly values?: ReadonlyArray<EnumValueDefinitionNode> | undefined;
 }
 export interface InputObjectTypeExtensionNode {
   readonly kind: Kind.INPUT_OBJECT_TYPE_EXTENSION;
-  readonly loc?: Location;
+  readonly loc?: Location | undefined;
   readonly name: NameNode;
-  readonly directives?: ReadonlyArray<ConstDirectiveNode>;
-  readonly fields?: ReadonlyArray<InputValueDefinitionNode>;
+  readonly directives?: ReadonlyArray<ConstDirectiveNode> | undefined;
+  readonly fields?: ReadonlyArray<InputValueDefinitionNode> | undefined;
 }

language/ast.js

@@ -64,4 +64,18 @@ /**
   SelectionSet: ['selections'],
-  Field: ['alias', 'name', 'arguments', 'directives', 'selectionSet'],
+  Field: [
+    'alias',
+    'name',
+    'arguments',
+    'directives',
+    'selectionSet',
+    // Note: Client Controlled Nullability is experimental and may be changed
+    // or removed in the future.
+    'nullabilityAssertion',
+  ],
   Argument: ['name', 'value'],
+  // Note: Client Controlled Nullability is experimental and may be changed
+  // or removed in the future.
+  ListNullabilityOperator: ['nullabilityAssertion'],
+  NonNullAssertion: ['nullabilityAssertion'],
+  ErrorBoundary: ['nullabilityAssertion'],
   FragmentSpread: ['name', 'directives'],
@@ -68,0 +82,0 @@ InlineFragment: ['typeCondition', 'directives', 'selectionSet'],

language/index.d.ts

@@ -27,2 +27,6 @@ export { Source } from './source';
   FieldNode,
+  NullabilityAssertionNode,
+  NonNullAssertionNode,
+  ErrorBoundaryNode,
+  ListNullabilityOperatorNode,
   ArgumentNode,
@@ -81,2 +85,3 @@ ConstArgumentNode,
   isSelectionNode,
+  isNullabilityAssertionNode,
   isValueNode,
@@ -83,0 +88,0 @@ isConstValueNode,

language/index.js

@@ -20,2 +20,3 @@ export { Source } from './source.js';
   isSelectionNode,
+  isNullabilityAssertionNode,
   isValueNode,
@@ -22,0 +23,0 @@ isConstValueNode,

language/kinds.d.ts

@@ -14,2 +14,6 @@ /**
   ARGUMENT = 'Argument',
+  /** Nullability Modifiers */
+  LIST_NULLABILITY_OPERATOR = 'ListNullabilityOperator',
+  NON_NULL_ASSERTION = 'NonNullAssertion',
+  ERROR_BOUNDARY = 'ErrorBoundary',
   /** Fragments */
@@ -16,0 +20,0 @@ FRAGMENT_SPREAD = 'FragmentSpread',

language/kinds.js

@@ -15,2 +15,6 @@ /**
   Kind['ARGUMENT'] = 'Argument';
+  /** Nullability Modifiers */
+  Kind['LIST_NULLABILITY_OPERATOR'] = 'ListNullabilityOperator';
+  Kind['NON_NULL_ASSERTION'] = 'NonNullAssertion';
+  Kind['ERROR_BOUNDARY'] = 'ErrorBoundary';
   /** Fragments */
@@ -17,0 +21,0 @@ Kind['FRAGMENT_SPREAD'] = 'FragmentSpread';

language/lexer.js

@@ -64,2 +64,3 @@ import { syntaxError } from '../error/syntaxError.js';
     kind === TokenKind.BANG ||
+    kind === TokenKind.QUESTION_MARK ||
     kind === TokenKind.DOLLAR ||
@@ -238,2 +239,9 @@ kind === TokenKind.AMP ||
         return createToken(lexer, TokenKind.BRACE_R, position, position + 1);
+      case 0x003f: // ?
+        return createToken(
+          lexer,
+          TokenKind.QUESTION_MARK,
+          position,
+          position + 1,
+        );
       // StringValue
@@ -240,0 +248,0 @@ case 0x0022: // "

language/parser.d.ts

@@ -31,2 +31,3 @@ import type { Maybe } from '../jsutils/Maybe';
   NameNode,
+  NullabilityAssertionNode,
   ObjectFieldNode,
@@ -67,4 +68,12 @@ ObjectTypeDefinitionNode,
    */
-  noLocation?: boolean;
+  noLocation?: boolean | undefined;
   /**
+   * Parser CPU and memory usage is linear to the number of tokens in a document
+   * however in extreme cases it becomes quadratic due to memory exhaustion.
+   * Parsing happens before validation so even invalid queries can burn lots of
+   * CPU time and memory.
+   * To prevent this you can set a maximum number of tokens allowed within a document.
+   */
+  maxTokens?: number | undefined;
+  /**
    * @deprecated will be removed in the v17.0.0
@@ -84,3 +93,25 @@ *
    */
-  allowLegacyFragmentVariables?: boolean;
+  allowLegacyFragmentVariables?: boolean | undefined;
+  /**
+   * EXPERIMENTAL:
+   *
+   * If enabled, the parser will understand and parse Client Controlled Nullability
+   * Designators contained in Fields. They'll be represented in the
+   * `nullabilityAssertion` field of the FieldNode.
+   *
+   * The syntax looks like the following:
+   *
+   * ```graphql
+   *   {
+   *     nullableField!
+   *     nonNullableField?
+   *     nonNullableSelectionSet? {
+   *       childField!
+   *     }
+   *   }
+   * ```
+   * Note: this feature is experimental and may change or be removed in the
+   * future.
+   */
+  experimentalClientControlledNullability?: boolean | undefined;
 }
@@ -93,3 +124,3 @@ /**
   source: string | Source,
-  options?: ParseOptions,
+  options?: ParseOptions | undefined,
 ): DocumentNode;
@@ -108,3 +139,3 @@ /**
   source: string | Source,
-  options?: ParseOptions,
+  options?: ParseOptions | undefined,
 ): ValueNode;
@@ -117,3 +148,3 @@ /**
   source: string | Source,
-  options?: ParseOptions,
+  options?: ParseOptions | undefined,
 ): ConstValueNode;
@@ -132,3 +163,3 @@ /**
   source: string | Source,
-  options?: ParseOptions,
+  options?: ParseOptions | undefined,
 ): TypeNode;
@@ -147,4 +178,5 @@ /**
 export declare class Parser {
-  protected _options: Maybe<ParseOptions>;
+  protected _options: ParseOptions;
   protected _lexer: Lexer;
+  protected _tokenCounter: number;
   constructor(source: string | Source, options?: ParseOptions);
@@ -224,2 +256,3 @@ /**
   parseField(): FieldNode;
+  parseNullabilityAssertion(): NullabilityAssertionNode | undefined;
   /**
@@ -499,3 +532,3 @@ * Arguments[Const] : ( Argument[?Const]+ )
     T extends {
-      loc?: Location;
+      loc?: Location | undefined;
     },
@@ -564,2 +597,3 @@ >(startToken: Token, node: T): T;
   delimitedMany<T>(delimiterKind: TokenKind, parseFn: () => T): Array<T>;
+  advanceLexer(): void;
 }

language/parser.js

@@ -73,6 +73,7 @@ import { syntaxError } from '../error/syntaxError.js';
 export class Parser {
-  constructor(source, options) {
+  constructor(source, options = {}) {
     const sourceObj = isSource(source) ? source : new Source(source);
     this._lexer = new Lexer(sourceObj);
     this._options = options;
+    this._tokenCounter = 0;
   }
@@ -303,2 +304,5 @@ /**
       arguments: this.parseArguments(false),
+      // Experimental support for Client Controlled Nullability changes
+      // the grammar of Field:
+      nullabilityAssertion: this.parseNullabilityAssertion(),
       directives: this.parseDirectives(false),
@@ -310,2 +314,32 @@ selectionSet: this.peek(TokenKind.BRACE_L)
   }
+  // TODO: add grammar comment after it finalizes
+  parseNullabilityAssertion() {
+    // Note: Client Controlled Nullability is experimental and may be changed or
+    // removed in the future.
+    if (this._options.experimentalClientControlledNullability !== true) {
+      return undefined;
+    }
+    const start = this._lexer.token;
+    let nullabilityAssertion;
+    if (this.expectOptionalToken(TokenKind.BRACKET_L)) {
+      const innerModifier = this.parseNullabilityAssertion();
+      this.expectToken(TokenKind.BRACKET_R);
+      nullabilityAssertion = this.node(start, {
+        kind: Kind.LIST_NULLABILITY_OPERATOR,
+        nullabilityAssertion: innerModifier,
+      });
+    }
+    if (this.expectOptionalToken(TokenKind.BANG)) {
+      nullabilityAssertion = this.node(start, {
+        kind: Kind.NON_NULL_ASSERTION,
+        nullabilityAssertion,
+      });
+    } else if (this.expectOptionalToken(TokenKind.QUESTION_MARK)) {
+      nullabilityAssertion = this.node(start, {
+        kind: Kind.ERROR_BOUNDARY,
+        nullabilityAssertion,
+      });
+    }
+    return nullabilityAssertion;
+  }
   parseArguments(isConst) {
@@ -366,3 +400,3 @@ const item = isConst ? this.parseConstArgument : this.parseArgument;
     //   - fragment FragmentName VariableDefinitions? on TypeCondition Directives? SelectionSet
-    if (this._options?.allowLegacyFragmentVariables === true) {
+    if (this._options.allowLegacyFragmentVariables === true) {
       return this.node(start, {
@@ -402,3 +436,3 @@ kind: Kind.FRAGMENT_DEFINITION,
       case TokenKind.INT:
-        this._lexer.advance();
+        this.advanceLexer();
         return this.node(token, {
@@ -409,3 +443,3 @@ kind: Kind.INT,
       case TokenKind.FLOAT:
-        this._lexer.advance();
+        this.advanceLexer();
         return this.node(token, {
@@ -419,3 +453,3 @@ kind: Kind.FLOAT,
       case TokenKind.NAME:
-        this._lexer.advance();
+        this.advanceLexer();
         switch (token.value) {
@@ -464,3 +498,3 @@ case 'true':
     const token = this._lexer.token;
-    this._lexer.advance();
+    this.advanceLexer();
     return this.node(token, {
@@ -1140,3 +1174,3 @@ kind: Kind.STRING,
   node(startToken, node) {
-    if (this._options?.noLocation !== true) {
+    if (this._options.noLocation !== true) {
       node.loc = new Location(
@@ -1163,3 +1197,3 @@ startToken,
     if (token.kind === kind) {
-      this._lexer.advance();
+      this.advanceLexer();
       return token;
@@ -1180,3 +1214,3 @@ }
     if (token.kind === kind) {
-      this._lexer.advance();
+      this.advanceLexer();
       return true;
@@ -1193,3 +1227,3 @@ }
     if (token.kind === TokenKind.NAME && token.value === value) {
-      this._lexer.advance();
+      this.advanceLexer();
     } else {
@@ -1210,3 +1244,3 @@ throw syntaxError(
     if (token.kind === TokenKind.NAME && token.value === value) {
-      this._lexer.advance();
+      this.advanceLexer();
       return true;
@@ -1282,2 +1316,16 @@ }
   }
+  advanceLexer() {
+    const { maxTokens } = this._options;
+    const token = this._lexer.advance();
+    if (maxTokens !== undefined && token.kind !== TokenKind.EOF) {
+      ++this._tokenCounter;
+      if (this._tokenCounter > maxTokens) {
+        throw syntaxError(
+          this._lexer.source,
+          token.start,
+          `Document contains more that ${maxTokens} tokens. Parsing aborted.`,
+        );
+      }
+    }
+  }
 }
@@ -1284,0 +1332,0 @@ /**

language/predicates.d.ts

@@ -6,2 +6,3 @@ import type {
   ExecutableDefinitionNode,
+  NullabilityAssertionNode,
   SelectionNode,
@@ -20,2 +21,5 @@ TypeDefinitionNode,
 export declare function isSelectionNode(node: ASTNode): node is SelectionNode;
+export declare function isNullabilityAssertionNode(
+  node: ASTNode,
+): node is NullabilityAssertionNode;
 export declare function isValueNode(node: ASTNode): node is ValueNode;
@@ -22,0 +26,0 @@ export declare function isConstValueNode(node: ASTNode): node is ConstValueNode;

language/predicates.js

@@ -22,2 +22,9 @@ import { Kind } from './kinds.js';
 }
+export function isNullabilityAssertionNode(node) {
+  return (
+    node.kind === Kind.LIST_NULLABILITY_OPERATOR ||
+    node.kind === Kind.NON_NULL_ASSERTION ||
+    node.kind === Kind.ERROR_BOUNDARY
+  );
+}
 export function isValueNode(node) {
@@ -24,0 +31,0 @@ return (

language/printer.js

@@ -45,4 +45,11 @@ import { printBlockString } from './blockString.js';
   Field: {
-    leave({ alias, name, arguments: args, directives, selectionSet }) {
-      const prefix = wrap('', alias, ': ') + name;
+    leave({
+      alias,
+      name,
+      arguments: args,
+      nullabilityAssertion,
+      directives,
+      selectionSet,
+    }) {
+      const prefix = join([wrap('', alias, ': '), name], '');
       let argsLine = prefix + wrap('(', join(args, ', '), ')');
@@ -52,6 +59,29 @@ if (argsLine.length > MAX_LINE_LENGTH) {
       }
-      return join([argsLine, join(directives, ' '), selectionSet], ' ');
+      return join([
+        argsLine,
+        // Note: Client Controlled Nullability is experimental and may be
+        // changed or removed in the future.
+        nullabilityAssertion,
+        wrap(' ', join(directives, ' ')),
+        wrap(' ', selectionSet),
+      ]);
     },
   },
   Argument: { leave: ({ name, value }) => name + ': ' + value },
+  // Nullability Modifiers
+  ListNullabilityOperator: {
+    leave({ nullabilityAssertion }) {
+      return join(['[', nullabilityAssertion, ']']);
+    },
+  },
+  NonNullAssertion: {
+    leave({ nullabilityAssertion }) {
+      return join([nullabilityAssertion, '!']);
+    },
+  },
+  ErrorBoundary: {
+    leave({ nullabilityAssertion }) {
+      return join([nullabilityAssertion, '?']);
+    },
+  },
   // Fragments
@@ -58,0 +88,0 @@ FragmentSpread: {

language/tokenKind.d.ts

@@ -9,2 +9,3 @@ /**
   BANG = '!',
+  QUESTION_MARK = '?',
   DOLLAR = '$',
@@ -11,0 +12,0 @@ AMP = '&',

language/tokenKind.js

@@ -10,2 +10,3 @@ /**
   TokenKind['BANG'] = '!';
+  TokenKind['QUESTION_MARK'] = '?';
   TokenKind['DOLLAR'] = '$';
@@ -12,0 +13,0 @@ TokenKind['AMP'] = '&';

language/visitor.d.ts

@@ -14,4 +14,4 @@ import type { ASTNode } from './ast';
 interface EnterLeaveVisitor<TVisitedNode extends ASTNode> {
-  readonly enter?: ASTVisitFn<TVisitedNode>;
-  readonly leave?: ASTVisitFn<TVisitedNode>;
+  readonly enter?: ASTVisitFn<TVisitedNode> | undefined;
+  readonly leave?: ASTVisitFn<TVisitedNode> | undefined;
 }
@@ -18,0 +18,0 @@ /**

package.json

 {
   "name": "graphql",
-  "version": "17.0.0-alpha.1.canary.pr.3658.null",
+  "version": "17.0.0-alpha.1.canary.pr.3659.5dba20aef36112d13569d5f296ef967383e60d0f",
   "description": "A Query Language and Runtime which can target any service.",
@@ -35,3 +35,3 @@ "license": "MIT",
   "publishConfig": {
-    "tag": "canary-pr-3658"
+    "tag": "canary-pr-3659"
   },
@@ -50,3 +50,3 @@ "type": "module",
   },
-  "deprecated": "You are using canary version build from https://github.com/graphql/graphql-js/pull/3658, no gurantees provided so please use your own discretion."
+  "deprecated": "You are using canary version build from https://github.com/graphql/graphql-js/pull/3659, no gurantees provided so please use your own discretion."
 }

type/definition.d.ts

@@ -328,7 +328,7 @@ import type { Maybe } from '../jsutils/Maybe';
   /** Serializes an internal value to include in a response. */
-  serialize?: GraphQLScalarSerializer<TExternal>;
+  serialize?: GraphQLScalarSerializer<TExternal> | undefined;
   /** Parses an externally provided value to use as an input. */
-  parseValue?: GraphQLScalarValueParser<TInternal>;
+  parseValue?: GraphQLScalarValueParser<TInternal> | undefined;
   /** Parses an externally provided literal value to use as an input. */
-  parseLiteral?: GraphQLScalarLiteralParser<TInternal>;
+  parseLiteral?: GraphQLScalarLiteralParser<TInternal> | undefined;
   extensions?: Maybe<Readonly<GraphQLScalarTypeExtensions>>;
@@ -430,3 +430,3 @@ astNode?: Maybe<ScalarTypeDefinitionNode>;
   description?: Maybe<string>;
-  interfaces?: ThunkReadonlyArray<GraphQLInterfaceType>;
+  interfaces?: ThunkReadonlyArray<GraphQLInterfaceType> | undefined;
   fields: ThunkObjMap<GraphQLFieldConfig<TSource, TContext>>;
@@ -499,5 +499,5 @@ isTypeOf?: Maybe<GraphQLIsTypeOfFn<TSource, TContext>>;
   type: GraphQLOutputType;
-  args?: GraphQLFieldConfigArgumentMap;
-  resolve?: GraphQLFieldResolver<TSource, TContext, TArgs>;
-  subscribe?: GraphQLFieldResolver<TSource, TContext, TArgs>;
+  args?: GraphQLFieldConfigArgumentMap | undefined;
+  resolve?: GraphQLFieldResolver<TSource, TContext, TArgs> | undefined;
+  subscribe?: GraphQLFieldResolver<TSource, TContext, TArgs> | undefined;
   deprecationReason?: Maybe<string>;
@@ -539,4 +539,4 @@ extensions?: Maybe<
   args: ReadonlyArray<GraphQLArgument>;
-  resolve?: GraphQLFieldResolver<TSource, TContext, TArgs>;
-  subscribe?: GraphQLFieldResolver<TSource, TContext, TArgs>;
+  resolve?: GraphQLFieldResolver<TSource, TContext, TArgs> | undefined;
+  subscribe?: GraphQLFieldResolver<TSource, TContext, TArgs> | undefined;
   deprecationReason: Maybe<string>;
@@ -610,3 +610,3 @@ extensions: Readonly<GraphQLFieldExtensions<TSource, TContext, TArgs>>;
   description?: Maybe<string>;
-  interfaces?: ThunkReadonlyArray<GraphQLInterfaceType>;
+  interfaces?: ThunkReadonlyArray<GraphQLInterfaceType> | undefined;
   fields: ThunkObjMap<GraphQLFieldConfig<TSource, TContext>>;
@@ -613,0 +613,0 @@ /**

type/directives.d.ts

@@ -68,2 +68,10 @@ import type { Maybe } from '../jsutils/Maybe';
 /**
+ * Used to conditionally defer fragments.
+ */
+export declare const GraphQLDeferDirective: GraphQLDirective;
+/**
+ * Used to conditionally stream list fields.
+ */
+export declare const GraphQLStreamDirective: GraphQLDirective;
+/**
  * Constant string used for default reason for a deprecation.
@@ -70,0 +78,0 @@ */

type/directives.js

@@ -11,3 +11,3 @@ import { inspect } from '../jsutils/inspect.js';
 } from './definition.js';
-import { GraphQLBoolean, GraphQLString } from './scalars.js';
+import { GraphQLBoolean, GraphQLInt, GraphQLString } from './scalars.js';
 /**
@@ -102,2 +102,50 @@ * Test if the given value is a GraphQL directive.
 /**
+ * Used to conditionally defer fragments.
+ */
+export const GraphQLDeferDirective = new GraphQLDirective({
+  name: 'defer',
+  description:
+    'Directs the executor to defer this fragment when the `if` argument is true or undefined.',
+  locations: [
+    DirectiveLocation.FRAGMENT_SPREAD,
+    DirectiveLocation.INLINE_FRAGMENT,
+  ],
+  args: {
+    if: {
+      type: new GraphQLNonNull(GraphQLBoolean),
+      description: 'Deferred when true or undefined.',
+      defaultValue: true,
+    },
+    label: {
+      type: GraphQLString,
+      description: 'Unique name',
+    },
+  },
+});
+/**
+ * Used to conditionally stream list fields.
+ */
+export const GraphQLStreamDirective = new GraphQLDirective({
+  name: 'stream',
+  description:
+    'Directs the executor to stream plural fields when the `if` argument is true or undefined.',
+  locations: [DirectiveLocation.FIELD],
+  args: {
+    if: {
+      type: new GraphQLNonNull(GraphQLBoolean),
+      description: 'Stream when true or undefined.',
+      defaultValue: true,
+    },
+    label: {
+      type: GraphQLString,
+      description: 'Unique name',
+    },
+    initialCount: {
+      defaultValue: 0,
+      type: GraphQLInt,
+      description: 'Number of items to return immediately',
+    },
+  },
+});
+/**
  * Constant string used for default reason for a deprecation.
@@ -104,0 +152,0 @@ */

type/index.d.ts

@@ -116,2 +116,4 @@ export type { Path as ResponsePath } from '../jsutils/Path';
   GraphQLSkipDirective,
+  GraphQLDeferDirective,
+  GraphQLStreamDirective,
   GraphQLDeprecatedDirective,
@@ -118,0 +120,0 @@ GraphQLSpecifiedByDirective,

type/index.js

@@ -76,2 +76,4 @@ export {
   GraphQLSkipDirective,
+  GraphQLDeferDirective,
+  GraphQLStreamDirective,
   GraphQLDeprecatedDirective,
@@ -78,0 +80,0 @@ GraphQLSpecifiedByDirective,

type/schema.d.ts

@@ -163,3 +163,3 @@ import type { Maybe } from '../jsutils/Maybe';
    */
-  assumeValid?: boolean;
+  assumeValid?: boolean | undefined;
 }
@@ -166,0 +166,0 @@ export interface GraphQLSchemaConfig extends GraphQLSchemaValidationOptions {

type/schema.js

@@ -144,3 +144,3 @@ import { inspect } from '../jsutils/inspect.js';
     this._typeMap = Object.create(null);
-    this._subTypeMap = Object.create(null);
+    this._subTypeMap = new Map();
     // Keep track of all implementations by interface name.
@@ -228,21 +228,16 @@ this._implementationsMap = Object.create(null);
   isSubType(abstractType, maybeSubType) {
-    let map = this._subTypeMap[abstractType.name];
-    if (map === undefined) {
-      map = Object.create(null);
+    let set = this._subTypeMap.get(abstractType);
+    if (set === undefined) {
       if (isUnionType(abstractType)) {
-        for (const type of abstractType.getTypes()) {
-          map[type.name] = true;
-        }
+        set = new Set(abstractType.getTypes());
       } else {
         const implementations = this.getImplementations(abstractType);
-        for (const type of implementations.objects) {
-          map[type.name] = true;
-        }
-        for (const type of implementations.interfaces) {
-          map[type.name] = true;
-        }
+        set = new Set([
+          ...implementations.objects,
+          ...implementations.interfaces,
+        ]);
       }
-      this._subTypeMap[abstractType.name] = map;
+      this._subTypeMap.set(abstractType, set);
     }
-    return map[maybeSubType.name] !== undefined;
+    return set.has(maybeSubType);
   }
@@ -249,0 +244,0 @@ getDirectives() {

type/validate.js

@@ -95,3 +95,3 @@ import { AccumulatorMap } from '../jsutils/AccumulatorMap.js';
   }
-  for (const [rootType, operationTypes] of rootTypesMap.entries()) {
+  for (const [rootType, operationTypes] of rootTypesMap) {
     if (operationTypes.length > 1) {
@@ -243,3 +243,3 @@ const operationList = andList(operationTypes);
 function validateInterfaces(context, type) {
-  const ifaceTypeNames = Object.create(null);
+  const ifaceTypeNames = new Set();
   for (const iface of type.getInterfaces()) {
@@ -261,3 +261,3 @@ if (!isInterfaceType(iface)) {
     }
-    if (ifaceTypeNames[iface.name]) {
+    if (ifaceTypeNames.has(iface.name)) {
       context.reportError(
@@ -269,3 +269,3 @@ `Type ${type.name} can only implement ${iface.name} once.`,
     }
-    ifaceTypeNames[iface.name] = true;
+    ifaceTypeNames.add(iface.name);
     validateTypeImplementsAncestors(context, type, iface);
@@ -362,5 +362,5 @@ validateTypeImplementsInterface(context, type, iface);
   }
-  const includedTypeNames = Object.create(null);
+  const includedTypeNames = new Set();
   for (const memberType of memberTypes) {
-    if (includedTypeNames[memberType.name]) {
+    if (includedTypeNames.has(memberType.name)) {
       context.reportError(
@@ -372,3 +372,3 @@ `Union type ${union.name} can only include type ${memberType.name} once.`,
     }
-    includedTypeNames[memberType.name] = true;
+    includedTypeNames.add(memberType.name);
     if (!isObjectType(memberType)) {
@@ -428,3 +428,3 @@ context.reportError(
   // are not redundantly reported.
-  const visitedTypes = Object.create(null);
+  const visitedTypes = new Set();
   // Array of types nodes used to produce meaningful errors
@@ -439,6 +439,6 @@ const fieldPath = [];
   function detectCycleRecursive(inputObj) {
-    if (visitedTypes[inputObj.name]) {
+    if (visitedTypes.has(inputObj)) {
       return;
     }
-    visitedTypes[inputObj.name] = true;
+    visitedTypes.add(inputObj);
     fieldPathIndexByTypeName[inputObj.name] = fieldPath.length;
@@ -445,0 +445,0 @@ const fields = Object.values(inputObj.getFields());

utilities/buildASTSchema.d.ts

@@ -12,3 +12,3 @@ import type { DocumentNode } from '../language/ast';
    */
-  assumeValidSDL?: boolean;
+  assumeValidSDL?: boolean | undefined;
 }
@@ -15,0 +15,0 @@ /**

utilities/coerceInputValue.js

@@ -115,3 +115,3 @@ import { didYouMean } from '../jsutils/didYouMean.js';
     let parseResult;
-    // Scalars and Enums determine if a input value is valid via parseValue(),
+    // Scalars and Enums determine if an input value is valid via parseValue(),
     // which can throw to indicate failure. If it throws, maintain a reference
@@ -118,0 +118,0 @@ // to the original error.

utilities/extendSchema.d.ts

@@ -13,3 +13,3 @@ import type { DocumentNode } from '../language/ast';
    */
-  assumeValidSDL?: boolean;
+  assumeValidSDL?: boolean | undefined;
 }
@@ -16,0 +16,0 @@ /**

utilities/extendSchema.js

@@ -0,1 +1,2 @@
+import { AccumulatorMap } from '../jsutils/AccumulatorMap.js';
 import { inspect } from '../jsutils/inspect.js';
@@ -7,6 +8,2 @@ import { invariant } from '../jsutils/invariant.js';
 import {
-  isTypeDefinitionNode,
-  isTypeExtensionNode,
-} from '../language/predicates.js';
-import {
   GraphQLEnumType,
@@ -76,3 +73,8 @@ GraphQLInputObjectType,
   const typeDefs = [];
-  const typeExtensionsMap = Object.create(null);
+  const scalarExtensions = new AccumulatorMap();
+  const objectExtensions = new AccumulatorMap();
+  const interfaceExtensions = new AccumulatorMap();
+  const unionExtensions = new AccumulatorMap();
+  const enumExtensions = new AccumulatorMap();
+  const inputObjectExtensions = new AccumulatorMap();
   // New directives and types are separate because a directives and types can
@@ -84,28 +86,50 @@ // have the same name. For example, a type named "skip".
   const schemaExtensions = [];
+  let isSchemaChanged = false;
   for (const def of documentAST.definitions) {
-    if (def.kind === Kind.SCHEMA_DEFINITION) {
-      schemaDef = def;
-    } else if (def.kind === Kind.SCHEMA_EXTENSION) {
-      schemaExtensions.push(def);
-    } else if (isTypeDefinitionNode(def)) {
-      typeDefs.push(def);
-    } else if (isTypeExtensionNode(def)) {
-      const extendedTypeName = def.name.value;
-      const existingTypeExtensions = typeExtensionsMap[extendedTypeName];
-      typeExtensionsMap[extendedTypeName] = existingTypeExtensions
-        ? existingTypeExtensions.concat([def])
-        : [def];
-    } else if (def.kind === Kind.DIRECTIVE_DEFINITION) {
-      directiveDefs.push(def);
+    switch (def.kind) {
+      case Kind.SCHEMA_DEFINITION:
+        schemaDef = def;
+        break;
+      case Kind.SCHEMA_EXTENSION:
+        schemaExtensions.push(def);
+        break;
+      case Kind.DIRECTIVE_DEFINITION:
+        directiveDefs.push(def);
+        break;
+      // Type Definitions
+      case Kind.SCALAR_TYPE_DEFINITION:
+      case Kind.OBJECT_TYPE_DEFINITION:
+      case Kind.INTERFACE_TYPE_DEFINITION:
+      case Kind.UNION_TYPE_DEFINITION:
+      case Kind.ENUM_TYPE_DEFINITION:
+      case Kind.INPUT_OBJECT_TYPE_DEFINITION:
+        typeDefs.push(def);
+        break;
+      // Type System Extensions
+      case Kind.SCALAR_TYPE_EXTENSION:
+        scalarExtensions.add(def.name.value, def);
+        break;
+      case Kind.OBJECT_TYPE_EXTENSION:
+        objectExtensions.add(def.name.value, def);
+        break;
+      case Kind.INTERFACE_TYPE_EXTENSION:
+        interfaceExtensions.add(def.name.value, def);
+        break;
+      case Kind.UNION_TYPE_EXTENSION:
+        unionExtensions.add(def.name.value, def);
+        break;
+      case Kind.ENUM_TYPE_EXTENSION:
+        enumExtensions.add(def.name.value, def);
+        break;
+      case Kind.INPUT_OBJECT_TYPE_EXTENSION:
+        inputObjectExtensions.add(def.name.value, def);
+        break;
+      default:
+        continue;
     }
+    isSchemaChanged = true;
   }
   // If this document contains no new types, extensions, or directives then
   // return the same unmodified GraphQLSchema instance.
-  if (
-    Object.keys(typeExtensionsMap).length === 0 &&
-    typeDefs.length === 0 &&
-    directiveDefs.length === 0 &&
-    schemaExtensions.length === 0 &&
-    schemaDef == null
-  ) {
+  if (!isSchemaChanged) {
     return schemaConfig;
@@ -205,3 +229,3 @@ }
     const config = type.toConfig();
-    const extensions = typeExtensionsMap[config.name] ?? [];
+    const extensions = inputObjectExtensions.get(config.name) ?? [];
     return new GraphQLInputObjectType({
@@ -221,3 +245,3 @@ ...config,
     const config = type.toConfig();
-    const extensions = typeExtensionsMap[type.name] ?? [];
+    const extensions = enumExtensions.get(type.name) ?? [];
     return new GraphQLEnumType({
@@ -234,3 +258,3 @@ ...config,
     const config = type.toConfig();
-    const extensions = typeExtensionsMap[config.name] ?? [];
+    const extensions = scalarExtensions.get(config.name) ?? [];
     let specifiedByURL = config.specifiedByURL;
@@ -248,3 +272,3 @@ for (const extensionNode of extensions) {
     const config = type.toConfig();
-    const extensions = typeExtensionsMap[config.name] ?? [];
+    const extensions = objectExtensions.get(config.name) ?? [];
     return new GraphQLObjectType({
@@ -265,3 +289,3 @@ ...config,
     const config = type.toConfig();
-    const extensions = typeExtensionsMap[config.name] ?? [];
+    const extensions = interfaceExtensions.get(config.name) ?? [];
     return new GraphQLInterfaceType({
@@ -282,3 +306,3 @@ ...config,
     const config = type.toConfig();
-    const extensions = typeExtensionsMap[config.name] ?? [];
+    const extensions = unionExtensions.get(config.name) ?? [];
     return new GraphQLUnionType({
@@ -447,5 +471,5 @@ ...config,
     const name = astNode.name.value;
-    const extensionASTNodes = typeExtensionsMap[name] ?? [];
     switch (astNode.kind) {
       case Kind.OBJECT_TYPE_DEFINITION: {
+        const extensionASTNodes = objectExtensions.get(name) ?? [];
         const allNodes = [astNode, ...extensionASTNodes];
@@ -462,2 +486,3 @@ return new GraphQLObjectType({
       case Kind.INTERFACE_TYPE_DEFINITION: {
+        const extensionASTNodes = interfaceExtensions.get(name) ?? [];
         const allNodes = [astNode, ...extensionASTNodes];
@@ -474,2 +499,3 @@ return new GraphQLInterfaceType({
       case Kind.ENUM_TYPE_DEFINITION: {
+        const extensionASTNodes = enumExtensions.get(name) ?? [];
         const allNodes = [astNode, ...extensionASTNodes];
@@ -485,2 +511,3 @@ return new GraphQLEnumType({
       case Kind.UNION_TYPE_DEFINITION: {
+        const extensionASTNodes = unionExtensions.get(name) ?? [];
         const allNodes = [astNode, ...extensionASTNodes];
@@ -496,2 +523,3 @@ return new GraphQLUnionType({
       case Kind.SCALAR_TYPE_DEFINITION: {
+        const extensionASTNodes = scalarExtensions.get(name) ?? [];
         return new GraphQLScalarType({
@@ -506,2 +534,3 @@ name,
       case Kind.INPUT_OBJECT_TYPE_DEFINITION: {
+        const extensionASTNodes = inputObjectExtensions.get(name) ?? [];
         const allNodes = [astNode, ...extensionASTNodes];
@@ -508,0 +537,0 @@ return new GraphQLInputObjectType({

validation/index.d.ts

@@ -5,2 +5,4 @@ export { validate } from './validate';
 export { specifiedRules } from './specifiedRules';
+export { DeferStreamDirectiveLabelRule } from './rules/DeferStreamDirectiveLabelRule';
+export { DeferStreamDirectiveOnRootFieldRule } from './rules/DeferStreamDirectiveOnRootFieldRule';
 export { ExecutableDefinitionsRule } from './rules/ExecutableDefinitionsRule';
@@ -23,2 +25,3 @@ export { FieldsOnCorrectTypeRule } from './rules/FieldsOnCorrectTypeRule';
 export { SingleFieldSubscriptionsRule } from './rules/SingleFieldSubscriptionsRule';
+export { StreamDirectiveOnListFieldRule } from './rules/StreamDirectiveOnListFieldRule';
 export { UniqueArgumentNamesRule } from './rules/UniqueArgumentNamesRule';
@@ -25,0 +28,0 @@ export { UniqueDirectivesPerLocationRule } from './rules/UniqueDirectivesPerLocationRule';

validation/index.js

@@ -5,2 +5,6 @@ export { validate } from './validate.js';
 export { specifiedRules } from './specifiedRules.js';
+// Spec Section: "Defer And Stream Directive Labels Are Unique"
+export { DeferStreamDirectiveLabelRule } from './rules/DeferStreamDirectiveLabelRule.js';
+// Spec Section: "Defer And Stream Directives Are Used On Valid Root Field"
+export { DeferStreamDirectiveOnRootFieldRule } from './rules/DeferStreamDirectiveOnRootFieldRule.js';
 // Spec Section: "Executable Definitions"
@@ -40,2 +44,4 @@ export { ExecutableDefinitionsRule } from './rules/ExecutableDefinitionsRule.js';
 export { SingleFieldSubscriptionsRule } from './rules/SingleFieldSubscriptionsRule.js';
+// Spec Section: "Stream Directives Are Used On List Fields"
+export { StreamDirectiveOnListFieldRule } from './rules/StreamDirectiveOnListFieldRule.js';
 // Spec Section: "Argument Uniqueness"
@@ -42,0 +48,0 @@ export { UniqueArgumentNamesRule } from './rules/UniqueArgumentNamesRule.js';

validation/rules/KnownTypeNamesRule.js

@@ -20,21 +20,15 @@ import { didYouMean } from '../../jsutils/didYouMean.js';
 export function KnownTypeNamesRule(context) {
-  const schema = context.getSchema();
-  const existingTypesMap = schema ? schema.getTypeMap() : Object.create(null);
-  const definedTypes = Object.create(null);
-  for (const def of context.getDocument().definitions) {
-    if (isTypeDefinitionNode(def)) {
-      definedTypes[def.name.value] = true;
-    }
-  }
-  const typeNames = [
+  const { definitions } = context.getDocument();
+  const existingTypesMap = context.getSchema()?.getTypeMap() ?? {};
+  const typeNames = new Set([
     ...Object.keys(existingTypesMap),
-    ...Object.keys(definedTypes),
-  ];
+    ...definitions.filter(isTypeDefinitionNode).map((def) => def.name.value),
+  ]);
   return {
     NamedType(node, _1, parent, _2, ancestors) {
       const typeName = node.name.value;
-      if (!existingTypesMap[typeName] && !definedTypes[typeName]) {
+      if (!typeNames.has(typeName)) {
         const definitionNode = ancestors[2] ?? parent;
         const isSDL = definitionNode != null && isSDLNode(definitionNode);
-        if (isSDL && standardTypeNames.includes(typeName)) {
+        if (isSDL && standardTypeNames.has(typeName)) {
           return;
@@ -44,3 +38,3 @@ }
           typeName,
-          isSDL ? standardTypeNames.concat(typeNames) : typeNames,
+          isSDL ? [...standardTypeNames, ...typeNames] : [...typeNames],
         );
@@ -57,4 +51,4 @@ context.reportError(
 }
-const standardTypeNames = [...specifiedScalarTypes, ...introspectionTypes].map(
-  (type) => type.name,
+const standardTypeNames = new Set(
+  [...specifiedScalarTypes, ...introspectionTypes].map((type) => type.name),
 );
@@ -61,0 +55,0 @@ function isSDLNode(value) {

validation/rules/NoFragmentCyclesRule.js

@@ -13,3 +13,3 @@ import { GraphQLError } from '../../error/GraphQLError.js';
   // are not redundantly reported.
-  const visitedFrags = Object.create(null);
+  const visitedFrags = new Set();
   // Array of AST nodes used to produce meaningful errors
@@ -30,7 +30,7 @@ const spreadPath = [];
   function detectCycleRecursive(fragment) {
-    if (visitedFrags[fragment.name.value]) {
+    if (visitedFrags.has(fragment.name.value)) {
       return;
     }
     const fragmentName = fragment.name.value;
-    visitedFrags[fragmentName] = true;
+    visitedFrags.add(fragmentName);
     const spreadNodes = context.getFragmentSpreads(fragment.selectionSet);
@@ -37,0 +37,0 @@ if (spreadNodes.length === 0) {

validation/rules/NoUndefinedVariablesRule.js

@@ -11,29 +11,23 @@ import { GraphQLError } from '../../error/GraphQLError.js';
 export function NoUndefinedVariablesRule(context) {
-  let variableNameDefined = Object.create(null);
   return {
-    OperationDefinition: {
-      enter() {
-        variableNameDefined = Object.create(null);
-      },
-      leave(operation) {
-        const usages = context.getRecursiveVariableUsages(operation);
-        for (const { node } of usages) {
-          const varName = node.name.value;
-          if (variableNameDefined[varName] !== true) {
-            context.reportError(
-              new GraphQLError(
-                operation.name
-                  ? `Variable "$${varName}" is not defined by operation "${operation.name.value}".`
-                  : `Variable "$${varName}" is not defined.`,
-                { nodes: [node, operation] },
-              ),
-            );
-          }
+    OperationDefinition(operation) {
+      const variableNameDefined = new Set(
+        operation.variableDefinitions?.map((node) => node.variable.name.value),
+      );
+      const usages = context.getRecursiveVariableUsages(operation);
+      for (const { node } of usages) {
+        const varName = node.name.value;
+        if (!variableNameDefined.has(varName)) {
+          context.reportError(
+            new GraphQLError(
+              operation.name
+                ? `Variable "$${varName}" is not defined by operation "${operation.name.value}".`
+                : `Variable "$${varName}" is not defined.`,
+              { nodes: [node, operation] },
+            ),
+          );
         }
-      },
+      }
     },
-    VariableDefinition(node) {
-      variableNameDefined[node.variable.name.value] = true;
-    },
   };
 }

validation/rules/NoUnusedFragmentsRule.js

@@ -11,7 +11,11 @@ import { GraphQLError } from '../../error/GraphQLError.js';
 export function NoUnusedFragmentsRule(context) {
-  const operationDefs = [];
+  const fragmentNameUsed = new Set();
   const fragmentDefs = [];
   return {
-    OperationDefinition(node) {
-      operationDefs.push(node);
+    OperationDefinition(operation) {
+      for (const fragment of context.getRecursivelyReferencedFragments(
+        operation,
+      )) {
+        fragmentNameUsed.add(fragment.name.value);
+      }
       return false;
@@ -25,13 +29,5 @@ },
       leave() {
-        const fragmentNameUsed = Object.create(null);
-        for (const operation of operationDefs) {
-          for (const fragment of context.getRecursivelyReferencedFragments(
-            operation,
-          )) {
-            fragmentNameUsed[fragment.name.value] = true;
-          }
-        }
         for (const fragmentDef of fragmentDefs) {
           const fragName = fragmentDef.name.value;
-          if (fragmentNameUsed[fragName] !== true) {
+          if (!fragmentNameUsed.has(fragName)) {
             context.reportError(
@@ -38,0 +34,0 @@ new GraphQLError(`Fragment "${fragName}" is never used.`, {

validation/rules/NoUnusedVariablesRule.js

@@ -11,33 +11,26 @@ import { GraphQLError } from '../../error/GraphQLError.js';
 export function NoUnusedVariablesRule(context) {
-  let variableDefs = [];
   return {
-    OperationDefinition: {
-      enter() {
-        variableDefs = [];
-      },
-      leave(operation) {
-        const variableNameUsed = Object.create(null);
-        const usages = context.getRecursiveVariableUsages(operation);
-        for (const { node } of usages) {
-          variableNameUsed[node.name.value] = true;
+    OperationDefinition(operation) {
+      const usages = context.getRecursiveVariableUsages(operation);
+      const variableNameUsed = new Set(
+        usages.map(({ node }) => node.name.value),
+      );
+      // FIXME: https://github.com/graphql/graphql-js/issues/2203
+      /* c8 ignore next */
+      const variableDefinitions = operation.variableDefinitions ?? [];
+      for (const variableDef of variableDefinitions) {
+        const variableName = variableDef.variable.name.value;
+        if (!variableNameUsed.has(variableName)) {
+          context.reportError(
+            new GraphQLError(
+              operation.name
+                ? `Variable "$${variableName}" is never used in operation "${operation.name.value}".`
+                : `Variable "$${variableName}" is never used.`,
+              { nodes: variableDef },
+            ),
+          );
         }
-        for (const variableDef of variableDefs) {
-          const variableName = variableDef.variable.name.value;
-          if (variableNameUsed[variableName] !== true) {
-            context.reportError(
-              new GraphQLError(
-                operation.name
-                  ? `Variable "$${variableName}" is never used in operation "${operation.name.value}".`
-                  : `Variable "$${variableName}" is never used.`,
-                { nodes: variableDef },
-              ),
-            );
-          }
-        }
-      },
+      }
     },
-    VariableDefinition(def) {
-      variableDefs.push(def);
-    },
   };
 }

validation/rules/OverlappingFieldsCanBeMergedRule.js

@@ -530,2 +530,12 @@ import { inspect } from '../../jsutils/inspect.js';
   }
+  // FIXME https://github.com/graphql/graphql-js/issues/2203
+  const directives1 = /* c8 ignore next */ node1.directives ?? [];
+  const directives2 = /* c8 ignore next */ node2.directives ?? [];
+  if (!sameStreams(directives1, directives2)) {
+    return [
+      [responseName, 'they have differing stream directives'],
+      [node1],
+      [node2],
+    ];
+  }
   // The return type for each field.
@@ -578,2 +588,18 @@ const type1 = def1?.type;
 }
+function getStreamDirective(directives) {
+  return directives.find((directive) => directive.name.value === 'stream');
+}
+function sameStreams(directives1, directives2) {
+  const stream1 = getStreamDirective(directives1);
+  const stream2 = getStreamDirective(directives2);
+  if (!stream1 && !stream2) {
+    // both fields do not have streams
+    return true;
+  } else if (stream1 && stream2) {
+    // check if both fields have equivalent streams
+    return stringifyArguments(stream1) === stringifyArguments(stream2);
+  }
+  // fields have a mix of stream and no stream
+  return false;
+}
 // Two types conflict if both types could not apply to a value simultaneously.
@@ -618,3 +644,3 @@ // Composite types are ignored as their individual field types will be compared
   const nodeAndDefs = Object.create(null);
-  const fragmentNames = Object.create(null);
+  const fragmentNames = new Set();
   _collectFieldsAndFragmentNames(
@@ -627,3 +653,3 @@ context,
   );
-  const result = [nodeAndDefs, Object.keys(fragmentNames)];
+  const result = [nodeAndDefs, [...fragmentNames]];
   cachedFieldsAndFragmentNames.set(selectionSet, result);
@@ -677,3 +703,3 @@ return result;
       case Kind.FRAGMENT_SPREAD:
-        fragmentNames[selection.name.value] = true;
+        fragmentNames.add(selection.name.value);
         break;
@@ -680,0 +706,0 @@ case Kind.INLINE_FRAGMENT: {

validation/rules/SingleFieldSubscriptionsRule.js

@@ -28,3 +28,3 @@ import { GraphQLError } from '../../error/GraphQLError.js';
           }
-          const fields = collectFields(
+          const { fields } = collectFields(
             schema,
@@ -50,4 +50,3 @@ fragments,
           for (const fieldNodes of fields.values()) {
-            const field = fieldNodes[0];
-            const fieldName = field.name.value;
+            const fieldName = fieldNodes[0].name.value;
             if (fieldName.startsWith('__')) {
@@ -54,0 +53,0 @@ context.reportError(

validation/specifiedRules.js

@@ -0,1 +1,5 @@
+// Spec Section: "Defer And Stream Directive Labels Are Unique"
+import { DeferStreamDirectiveLabelRule } from './rules/DeferStreamDirectiveLabelRule.js';
+// Spec Section: "Defer And Stream Directives Are Used On Valid Root Field"
+import { DeferStreamDirectiveOnRootFieldRule } from './rules/DeferStreamDirectiveOnRootFieldRule.js';
 // Spec Section: "Executable Definitions"
@@ -44,2 +48,4 @@ import { ExecutableDefinitionsRule } from './rules/ExecutableDefinitionsRule.js';
 import { SingleFieldSubscriptionsRule } from './rules/SingleFieldSubscriptionsRule.js';
+// Spec Section: "Stream Directives Are Used On List Fields"
+import { StreamDirectiveOnListFieldRule } from './rules/StreamDirectiveOnListFieldRule.js';
 import { UniqueArgumentDefinitionNamesRule } from './rules/UniqueArgumentDefinitionNamesRule.js';
@@ -95,2 +101,5 @@ // Spec Section: "Argument Uniqueness"
   UniqueDirectivesPerLocationRule,
+  DeferStreamDirectiveOnRootFieldRule,
+  DeferStreamDirectiveLabelRule,
+  StreamDirectiveOnListFieldRule,
   KnownArgumentNamesRule,
@@ -97,0 +106,0 @@ UniqueArgumentNamesRule,

validation/validate.js

@@ -41,3 +41,5 @@ import { GraphQLError } from '../error/GraphQLError.js';
   assertValidSchema(schema);
-  const abortObj = Object.freeze({});
+  const abortError = new GraphQLError(
+    'Too many validation errors, error limit reached. Validation aborted.',
+  );
   const errors = [];
@@ -50,9 +52,3 @@ const context = new ValidationContext(
       if (errors.length >= maxErrors) {
-        errors.push(
-          new GraphQLError(
-            'Too many validation errors, error limit reached. Validation aborted.',
-          ),
-        );
-        // eslint-disable-next-line @typescript-eslint/no-throw-literal
-        throw abortObj;
+        throw abortError;
       }
@@ -69,3 +65,5 @@ errors.push(error);
   } catch (e) {
-    if (e !== abortObj) {
+    if (e === abortError) {
+      errors.push(abortError);
+    } else {
       throw e;
@@ -72,0 +70,0 @@ }

validation/ValidationContext.js

@@ -64,3 +64,3 @@ import { Kind } from '../language/kinds.js';
       fragments = [];
-      const collectedNames = Object.create(null);
+      const collectedNames = new Set();
       const nodesToVisit = [operation.selectionSet];
@@ -71,4 +71,4 @@ let node;
           const fragName = spread.name.value;
-          if (collectedNames[fragName] !== true) {
-            collectedNames[fragName] = true;
+          if (!collectedNames.has(fragName)) {
+            collectedNames.add(fragName);
             const fragment = this.getFragment(fragName);
@@ -75,0 +75,0 @@ if (fragment) {

New alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Deprecated

Maintenance

The maintainer of the package marked it as deprecated. This could indicate that a single version should not be used, or that the package is no longer maintained and any new vulnerabilities will not be fixed.

Found 1 instance in 1 package

Fixed alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Deprecated

Maintenance

The maintainer of the package marked it as deprecated. This could indicate that a single version should not be used, or that the package is no longer maintained and any new vulnerabilities will not be fixed.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

725744

increased by7.98%

Number of package files

266

increased by3.1%

Lines of code

22232

increased by8.13%

No dependency changes