Add TS typings (#2102)

Copied from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/54712a7e28090c5b1253b746d1878003c954f3ff/types/graphql
All credits goes to original authors of '*.d.ts' files:
@TonyPythoneer @calebmer @intellix @firede @kepennar @freiksenet @IvanGoncharov @DxCx @rportugal @tgriesser @dyst5422 @adnsio @divyenduz @bradzacher @clayne11 @JCMais @langpavel @mc0 @martijnwalraven @jedmao

package.json

@@ -23,15 +23,16 @@
     "node": ">= 6.x"
   },
   "scripts": {
-    "test": "npm run prettier:check && npm run lint && npm run check && npm run testonly",
-    "test:ci": "yarn check --integrity && npm run prettier:check && npm run lint -- --no-cache && npm run check && npm run testonly:cover && npm run build",
+    "test": "npm run prettier:check && npm run lint && npm run check && npm run testonly && npm run check:ts",
+    "test:ci": "yarn check --integrity && npm run prettier:check && npm run lint -- --no-cache && npm run check && npm run testonly:cover && npm run check:ts && npm run build",
     "testonly": "mocha --full-trace src/**/__tests__/**/*-test.js",
     "testonly:cover": "nyc npm run testonly",
     "lint": "eslint --cache --report-unused-disable-directives src resources",
     "benchmark": "node --noconcurrent_sweeping --expose-gc --predictable ./resources/benchmark.js",
-    "prettier": "prettier --ignore-path .gitignore --write --list-different \"**/*.{js,md,json,yml}\"",
-    "prettier:check": "prettier --ignore-path .gitignore --check \"**/*.{js,md,json,yml}\"",
+    "prettier": "prettier --ignore-path .gitignore --write --list-different \"**/*.{js,ts,md,json,yml}\"",
+    "prettier:check": "prettier --ignore-path .gitignore --check \"**/*.{js,ts,md,json,yml}\"",
     "check": "flow check",
+    "check:ts": "dtslint tstypes",
     "check:cover": "node resources/check-cover.js && nyc report --nycrc-path .nycflowrc.yml",
     "build": "node resources/build.js",
     "changelog": "node resources/gen-changelog.js",
@@ -50,6 +51,7 @@
     "@babel/register": "7.5.5",
     "babel-eslint": "10.0.2",
     "chai": "4.2.0",
+    "dtslint": "^0.8.0",
     "eslint": "5.16.0",
     "eslint-plugin-flowtype": "3.12.1",
     "flow-bin": "0.105.2",

resources/build.js

@@ -29,6 +29,16 @@ if (require.main === module) {
     }
   }
 
+  const tsFiles = readdirRecursive('./tstypes', { ignoreDir: /^__.*__$/ });
+  for (const filepath of tsFiles) {
+    if (filepath.endsWith('.d.ts')) {
+      const srcPath = path.join('./tstypes', filepath);
+      const destPath = path.join('./dist', filepath);
+
+      copyFile(srcPath, destPath);
+    }
+  }
+
   const packageJSON = buildPackageJSON();
   assert(
     packageJSON.version === require('../dist/version').version,

tstypes/error/GraphQLError.d.ts

@@ -0,0 +1,78 @@
+import Maybe from '../tsutils/Maybe';
+import { getLocation } from '../language';
+import { ASTNode } from '../language/ast';
+import { Source } from '../language/source';
+import { SourceLocation } from '../language/location';
+
+/**
+ * A GraphQLError describes an Error found during the parse, validate, or
+ * execute phases of performing a GraphQL operation. In addition to a message
+ * and stack trace, it also includes information about the locations in a
+ * GraphQL document and/or execution result that correspond to the Error.
+ */
+export class GraphQLError extends Error {
+  /**
+   * A message describing the Error for debugging purposes.
+   *
+   * Enumerable, and appears in the result of JSON.stringify().
+   *
+   * Note: should be treated as readonly, despite invariant usage.
+   */
+  message: string;
+
+  /**
+   * An array of { line, column } locations within the source GraphQL document
+   * which correspond to this error.
+   *
+   * Errors during validation often contain multiple locations, for example to
+   * point out two things with the same name. Errors during execution include a
+   * single location, the field which produced the error.
+   *
+   * Enumerable, and appears in the result of JSON.stringify().
+   */
+  readonly locations: ReadonlyArray<SourceLocation> | undefined;
+
+  /**
+   * An array describing the JSON-path into the execution response which
+   * corresponds to this error. Only included for errors during execution.
+   *
+   * Enumerable, and appears in the result of JSON.stringify().
+   */
+  readonly path: ReadonlyArray<string | number> | undefined;
+
+  /**
+   * An array of GraphQL AST Nodes corresponding to this error.
+   */
+  readonly nodes: ReadonlyArray<ASTNode> | undefined;
+
+  /**
+   * The source GraphQL document corresponding to this error.
+   */
+  readonly source: Source | undefined;
+
+  /**
+   * An array of character offsets within the source GraphQL document
+   * which correspond to this error.
+   */
+  readonly positions: ReadonlyArray<number> | undefined;
+
+  /**
+   * The original error thrown from a field resolver during execution.
+   */
+  readonly originalError: Maybe<Error>;
+
+  /**
+   * Extension fields to add to the formatted error.
+   */
+  readonly extensions: { [key: string]: any } | undefined;
+
+  constructor(
+    message: string,
+    nodes?: ReadonlyArray<ASTNode> | ASTNode | undefined,
+    source?: Maybe<Source>,
+    positions?: Maybe<ReadonlyArray<number>>,
+    path?: Maybe<ReadonlyArray<string | number>>,
+    originalError?: Maybe<Error>,
+    extensions?: Maybe<{ [key: string]: any }>,
+  );
+}

tstypes/error/formatError.d.ts

@@ -0,0 +1,39 @@
+import { GraphQLError } from './GraphQLError';
+import { SourceLocation } from '../language/location';
+
+/**
+ * Given a GraphQLError, format it according to the rules described by the
+ * Response Format, Errors section of the GraphQL Specification.
+ */
+export function formatError(error: GraphQLError): GraphQLFormattedError;
+
+/**
+ * @see https://github.com/graphql/graphql-spec/blob/master/spec/Section%207%20--%20Response.md#errors
+ */
+export interface GraphQLFormattedError<
+  TExtensions extends Record<string, any> = Record<string, any>
+> {
+  /**
+   * A short, human-readable summary of the problem that **SHOULD NOT** change
+   * from occurrence to occurrence of the problem, except for purposes of
+   * localization.
+   */
+  readonly message: string;
+  /**
+   * If an error can be associated to a particular point in the requested
+   * GraphQL document, it should contain a list of locations.
+   */
+  readonly locations?: ReadonlyArray<SourceLocation>;
+  /**
+   * If an error can be associated to a particular field in the GraphQL result,
+   * it _must_ contain an entry with the key `path` that details the path of
+   * the response field which experienced the error. This allows clients to
+   * identify whether a null result is intentional or caused by a runtime error.
+   */
+  readonly path?: ReadonlyArray<string | number>;
+  /**
+   * Reserved for implementors to extend the protocol however they see fit,
+   * and hence there are no additional restrictions on its contents.
+   */
+  readonly extensions?: TExtensions;
+}

tstypes/error/index.d.ts

@@ -0,0 +1,5 @@
+export { GraphQLError } from './GraphQLError';
+export { syntaxError } from './syntaxError';
+export { locatedError } from './locatedError';
+export { printError } from './printError';
+export { formatError, GraphQLFormattedError } from './formatError';

tstypes/error/locatedError.d.ts

@@ -0,0 +1,13 @@
+import { GraphQLError } from './GraphQLError';
+import { ASTNode } from '../language/ast';
+
+/**
+ * Given an arbitrary Error, presumably thrown while attempting to execute a
+ * GraphQL operation, produce a new GraphQLError aware of the location in the
+ * document responsible for the original Error.
+ */
+export function locatedError(
+  originalError: Error | GraphQLError,
+  nodes: ReadonlyArray<ASTNode>,
+  path: ReadonlyArray<string | number>,
+): GraphQLError;

tstypes/error/printError.d.ts

@@ -0,0 +1,7 @@
+import { GraphQLError } from './GraphQLError';
+
+/**
+ * Prints a GraphQLError to a string, representing useful location information
+ * about the error's position in the source.
+ */
+export function printError(error: GraphQLError): string;

tstypes/error/syntaxError.d.ts

@@ -0,0 +1,12 @@
+import { Source } from '../language/source';
+import { GraphQLError } from './GraphQLError';
+
+/**
+ * Produces a GraphQLError representing a syntax error, containing useful
+ * descriptive information about the syntax error's position in the source.
+ */
+export function syntaxError(
+  source: Source,
+  position: number,
+  description: string,
+): GraphQLError;

tstypes/execution/execute.d.ts

@@ -0,0 +1,189 @@
+import Maybe from '../tsutils/Maybe';
+import { GraphQLError, locatedError } from '../error';
+import { GraphQLSchema } from '../type/schema';
+import {
+  GraphQLField,
+  GraphQLFieldResolver,
+  ResponsePath,
+  GraphQLObjectType,
+  GraphQLResolveInfo,
+} from '../type/definition';
+import {
+  DirectiveNode,
+  DocumentNode,
+  OperationDefinitionNode,
+  SelectionSetNode,
+  FieldNode,
+  InlineFragmentNode,
+  FragmentDefinitionNode,
+} from '../language/ast';
+import { PromiseOrValue } from '../jsutils/PromiseOrValue';
+
+/**
+ * Data that must be available at all points during query execution.
+ *
+ * Namely, schema of the type system that is currently executing,
+ * and the fragments defined in the query document
+ */
+export interface ExecutionContext {
+  schema: GraphQLSchema;
+  fragments: { [key: string]: FragmentDefinitionNode };
+  rootValue: any;
+  contextValue: any;
+  operation: OperationDefinitionNode;
+  variableValues: { [key: string]: any };
+  fieldResolver: GraphQLFieldResolver<any, any>;
+  errors: GraphQLError[];
+}
+
+export interface ExecutionResultDataDefault {
+  [key: string]: any;
+}
+
+/**
+ * The result of GraphQL execution.
+ *
+ *   - `errors` is included when any errors occurred as a non-empty array.
+ *   - `data` is the result of a successful execution of the query.
+ */
+export interface ExecutionResult<TData = ExecutionResultDataDefault> {
+  errors?: ReadonlyArray<GraphQLError>;
+  data?: TData;
+}
+
+export type ExecutionArgs = {
+  schema: GraphQLSchema;
+  document: DocumentNode;
+  rootValue?: any;
+  contextValue?: any;
+  variableValues?: Maybe<{ [key: string]: any }>;
+  operationName?: Maybe<string>;
+  fieldResolver?: Maybe<GraphQLFieldResolver<any, any>>;
+};
+
+/**
+ * Implements the "Evaluating requests" section of the GraphQL specification.
+ *
+ * Returns either a synchronous ExecutionResult (if all encountered resolvers
+ * are synchronous), or a Promise of an ExecutionResult that will eventually be
+ * resolved and never rejected.
+ *
+ * If the arguments to this function do not result in a legal execution context,
+ * a GraphQLError will be thrown immediately explaining the invalid input.
+ *
+ * Accepts either an object with named arguments, or individual arguments.
+ */
+export function execute<TData = ExecutionResultDataDefault>(
+  args: ExecutionArgs,
+): PromiseOrValue<ExecutionResult<TData>>;
+export function execute<TData = ExecutionResultDataDefault>(
+  schema: GraphQLSchema,
+  document: DocumentNode,
+  rootValue?: any,
+  contextValue?: any,
+  variableValues?: Maybe<{ [key: string]: any }>,
+  operationName?: Maybe<string>,
+  fieldResolver?: Maybe<GraphQLFieldResolver<any, any>>,
+): PromiseOrValue<ExecutionResult<TData>>;
+
+/**
+ * Given a ResponsePath (found in the `path` entry in the information provided
+ * as the last argument to a field resolver), return an Array of the path keys.
+ */
+export function responsePathAsArray(
+  path: ResponsePath,
+): ReadonlyArray<string | number>;
+
+/**
+ * Given a ResponsePath and a key, return a new ResponsePath containing the
+ * new key.
+
+ */
+export function addPath(
+  prev: ResponsePath | undefined,
+  key: string | number,
+): { prev: ResponsePath | undefined; key: string | number };
+
+/**
+ * Essential assertions before executing to provide developer feedback for
+ * improper use of the GraphQL library.
+ */
+export function assertValidExecutionArguments(
+  schema: GraphQLSchema,
+  document: DocumentNode,
+  rawVariableValues: Maybe<{ [key: string]: any }>,
+): void;
+
+/**
+ * Constructs a ExecutionContext object from the arguments passed to
+ * execute, which we will pass throughout the other execution methods.
+ *
+ * Throws a GraphQLError if a valid execution context cannot be created.
+ */
+export function buildExecutionContext(
+  schema: GraphQLSchema,
+  document: DocumentNode,
+  rootValue: any,
+  contextValue: any,
+  rawVariableValues: Maybe<{ [key: string]: any }>,
+  operationName: Maybe<string>,
+  fieldResolver: Maybe<GraphQLFieldResolver<any, any>>,
+): ReadonlyArray<GraphQLError> | ExecutionContext;
+
+/**
+ * Given a selectionSet, adds all of the fields in that selection to
+ * the passed in map of fields, and returns it at the end.
+ *
+ * CollectFields requires the "runtime type" of an object. For a field which
+ * returns an Interface or Union type, the "runtime type" will be the actual
+ * Object type returned by that field.
+ */
+export function collectFields(
+  exeContext: ExecutionContext,
+  runtimeType: GraphQLObjectType,
+  selectionSet: SelectionSetNode,
+  fields: { [key: string]: Array<FieldNode> },
+  visitedFragmentNames: { [key: string]: boolean },
+): { [key: string]: Array<FieldNode> };
+
+export function buildResolveInfo(
+  exeContext: ExecutionContext,
+  fieldDef: GraphQLField<any, any>,
+  fieldNodes: ReadonlyArray<FieldNode>,
+  parentType: GraphQLObjectType,
+  path: ResponsePath,
+): GraphQLResolveInfo;
+
+// Isolates the "ReturnOrAbrupt" behavior to not de-opt the `resolveField`
+// function. Returns the result of resolveFn or the abrupt-return Error object.
+export function resolveFieldValueOrError<TSource>(
+  exeContext: ExecutionContext,
+  fieldDef: GraphQLField<TSource, any>,
+  fieldNodes: ReadonlyArray<FieldNode>,
+  resolveFn: GraphQLFieldResolver<TSource, any>,
+  source: TSource,
+  info: GraphQLResolveInfo,
+): Error | any;
+
+/**
+ * If a resolve function is not given, then a default resolve behavior is used
+ * which takes the property of the source object of the same name as the field
+ * and returns it as the result, or if it's a function, returns the result
+ * of calling that function while passing along args and context.
+ */
+export const defaultFieldResolver: GraphQLFieldResolver<any, any>;
+
+/**
+ * This method looks up the field on the given type defintion.
+ * It has special casing for the two introspection fields, __schema
+ * and __typename. __typename is special because it can always be
+ * queried as a field, even in situations where no other fields
+ * are allowed, like on a Union. __schema could get automatically
+ * added to the query type, but that would require mutating type
+ * definitions, which would cause issues.
+ */
+export function getFieldDef(
+  schema: GraphQLSchema,
+  parentType: GraphQLObjectType,
+  fieldName: string,
+): Maybe<GraphQLField<any, any>>;