Feb 10, 2023 · Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022
diff --git a/docs/architecture/Parser.mdx b/docs/architecture/Parser.mdx
  lib?: string[];
  moduleResolver?: string;
  program?: import('typescript').Program;
  project?: string | string[];
  project?: string | string[] | true;
  projectFolderIgnoreList?: string[];
  tsconfigRootDir?: string;
  warnOnUnsupportedTypeScriptVersion?: boolean;
 - Accepted values:

  ```js
  // find the tsconfig.json nearest each source file
  project: true,

  // path
  project: './tsconfig.json';

  project: ['./packages/**/tsconfig.json', './separate-package/tsconfig.json'];
  ```

 - If `true`, each source file's parse will find the nearest `tsconfig.json` file to that source file.

  - This is done by checking that source file's directory tree for the nearest `tsconfig.json`.

 - If you use project references, TypeScript will not automatically use project references to resolve files. This means that you will have to add each referenced tsconfig to the `project` field either separately, or via a glob.

 - Note that using wide globs `**` in your `parserOptions.project` may cause performance implications. Instead of globs that use `**` to recursively check all folders, prefer paths that use a single `*` at a time. For more info see [#2611](https://github.com/typescript-eslint/typescript-eslint/issues/2611).
diff --git a/docs/architecture/TypeScript-ESTree.mdx b/docs/architecture/TypeScript-ESTree.mdx
  preserveNodeMaps?: boolean;

  /**
   * Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s).
   * Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s),
   * or `true` to find the nearest tsconfig.json to the file.
   * If this is provided, type information will be returned.
   */
  project?: string | string[];
  project?: string | string[] | true;

  /**
   * If you provide a glob (or globs) to the project option, you can use this option to ignore certain folders from
diff --git a/docs/linting/Typed_Linting.mdx b/docs/linting/Typed_Linting.mdx
  parser: '@typescript-eslint/parser',
  // Added lines start
  parserOptions: {
    project:['./tsconfig.json'],
    project:true,
    tsconfigRootDir: __dirname,
  },
  // Added lines end
 With that done, run the same lint command you ran before.
 You may see new rules reporting errors based on type information!

 ## Specifying TSConfigs

 The `parserOptions.project` option can be turned on with either:

 - `true`: to always use `tsconfig.json`s nearest to source files
 - `string | string[]`: any number of glob paths to match TSConfig files relative to the

 For example, if you use a specific `tsconfig.eslint.json` for linting, you'd specify:

 ```js title=".eslintrc.js"
 module.exports = {
  // ...
  parserOptions: {
    project: './tsconfig.eslint.json',
  },
  // ...
 };
 ```

 See [the `@typescript-eslint/parser` docs for more details](https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/parser/README.md#parseroptionsproject).

 :::note
 If your project is a multi-package monorepo, see [our docs on configuring a monorepo](./typed-linting/Monorepos.mdx).
 :::

 ## FAQs

 ### How is performance?
diff --git a/docs/linting/typed-linting/Monorepos.mdx b/docs/linting/typed-linting/Monorepos.mdx
  parserOptions: {
    tsconfigRootDir: __dirname,
    // Remove this line
    project:['./tsconfig.json'],
    project:true,
    // Add this line
    project: ['./tsconfig.eslint.json', './packages/*/tsconfig.json'],
  },
diff --git a/packages/types/src/parser-options.ts b/packages/types/src/parser-options.ts
  filePath?: string;
  loc?: boolean;
  program?: Program;
  project?: string | string[];
  project?: string | string[] | true;
  projectFolderIgnoreList?: (string | RegExp)[];
  range?: boolean;
  sourceType?: SourceType;
diff --git a/packages/typescript-estree/src/parseSettings/ExpiringCache.ts b/packages/typescript-estree/src/parseSettings/ExpiringCache.ts
 export const DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS = 30;
 const ZERO_HR_TIME: [number, number] = [0, 0];

 export interface CacheLike<Key, Value> {
  get(key: Key): Value | void;
  set(key: Key, value: Value): this;
 }

 /**
 * A map with key-level expiration.
 */
 export class ExpiringCache<TKey, TValue> {
 export class ExpiringCache<TKey, TValue>implements CacheLike<TKey, TValue>{
  readonly #cacheDurationSeconds: CacheDurationSeconds;
  /**
   * The mapping of path-like string to the resolved TSConfig(s)
   */
  protected readonly map = new Map<

  readonly #map = new Map<
    TKey,
    Readonly<{
      value: TValue;
  }

  set(key: TKey, value: TValue): this {
    this.map.set(key, {
    this.#map.set(key, {
      value,
      lastSeen:
        this.#cacheDurationSeconds === 'Infinity'
  }

  get(key: TKey): TValue | undefined {
    const entry = this.map.get(key);
    const entry = this.#map.get(key);
    if (entry?.value != null) {
      if (this.#cacheDurationSeconds === 'Infinity') {
        return entry.value;
        return entry.value;
      } else {
        // key has expired - clean it up to free up memory
        this.cleanupKey(key);
        this.#map.delete(key);
      }
    }
    // no hit :'(
    return undefined;
  }

  protected cleanupKey(key: TKey): void {
    this.map.delete(key);
  }

  get size(): number {
    return this.map.size;
  }

  clear(): void {
    this.map.clear();
    this.#map.clear();
  }
 }
diff --git a/packages/typescript-estree/src/parseSettings/createParseSettings.ts b/packages/typescript-estree/src/parseSettings/createParseSettings.ts

 import { ensureAbsolutePath } from '../create-program/shared';
 import type { TSESTreeOptions } from '../parser-options';
 import {
  DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS,
  ExpiringCache,
 } from './ExpiringCache';
 import { getProjectConfigFiles } from './getProjectConfigFiles';
 import type { MutableParseSettings } from './index';
 import { inferSingleRun } from './inferSingleRun';
 import { resolveProjectList } from './resolveProjectList';
  'typescript-eslint:typescript-estree:parser:parseSettings:createParseSettings',
 );

 let TSCONFIG_MATCH_CACHE: ExpiringCache<string, string> | null;

 export function createParseSettings(
  code: string,
  options: Partial<TSESTreeOptions> = {},
 ): MutableParseSettings {
  const singleRun = inferSingleRun(options);
  const tsconfigRootDir =
    typeof options.tsconfigRootDir === 'string'
      ? options.tsconfigRootDir
    programs: Array.isArray(options.programs) ? options.programs : null,
    projects: [],
    range: options.range === true,
    singleRun: inferSingleRun(options),
    singleRun,
    tokens: options.tokens === true ? [] : null,
    tsconfigMatchCache: (TSCONFIG_MATCH_CACHE ??= new ExpiringCache(
      singleRun
        ? 'Infinity'
        : options.cacheLifetime?.glob ??
          DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS,
    )),
    tsconfigRootDir,
  };

  if (!parseSettings.programs) {
    parseSettings.projects = resolveProjectList({
      cacheLifetime: options.cacheLifetime,
      project: options.project,
      project:getProjectConfigFiles(parseSettings,options.project),
      projectFolderIgnoreList: options.projectFolderIgnoreList,
      singleRun: parseSettings.singleRun,
      tsconfigRootDir: tsconfigRootDir,
diff --git a/packages/typescript-estree/src/parseSettings/getProjectConfigFiles.ts b/packages/typescript-estree/src/parseSettings/getProjectConfigFiles.ts
 import debug from 'debug';
 import * as fs from 'fs';
 import * as path from 'path';

 import type { ParseSettings } from '.';

 const log = debug('typescript-eslint:typescript-estree:getProjectConfigFiles');

 /**
 * Checks for a matching TSConfig to a file including its parent directories,
 * permanently caching results under each directory it checks.
 *
 * @remarks
 * We don't (yet!) have a way to attach file watchers on disk, but still need to
 * cache file checks for rapid subsequent calls to fs.existsSync. See discussion
 * in https://github.com/typescript-eslint/typescript-eslint/issues/101.
 */
 export function getProjectConfigFiles(
  parseSettings: Pick<
    ParseSettings,
    'filePath' | 'tsconfigMatchCache' | 'tsconfigRootDir'
  >,
  project: string | string[] | true | undefined,
 ): string[] | undefined {
  if (project !== true) {
    return project === undefined || Array.isArray(project)
      ? project
      : [project];
  }

  log('Looking for tsconfig.json at or above file: %s', parseSettings.filePath);
  let directory = path.dirname(parseSettings.filePath);
  const checkedDirectories = [directory];

  do {
    log('Checking tsconfig.json path: %s', directory);
    const tsconfigPath = path.join(directory, 'tsconfig.json');
    const cached =
      parseSettings.tsconfigMatchCache.get(directory) ??
      (fs.existsSync(tsconfigPath) && tsconfigPath);

    if (cached) {
      for (const directory of checkedDirectories) {
        parseSettings.tsconfigMatchCache.set(directory, cached);
      }
      return [cached];
    }

    directory = path.dirname(directory);
    checkedDirectories.push(directory);
  } while (
    directory.length > 1 &&
    directory.length >= parseSettings.tsconfigRootDir.length
  );

  throw new Error(
    `project was set to \`true\` but couldn't find any tsconfig.json relative to '${parseSettings.filePath}' within '${parseSettings.tsconfigRootDir}'.`,
  );
 }
diff --git a/packages/typescript-estree/src/parseSettings/index.ts b/packages/typescript-estree/src/parseSettings/index.ts

 import type { CanonicalPath } from '../create-program/shared';
 import type { TSESTree } from '../ts-estree';
 import type { CacheLike } from './ExpiringCache';

 type DebugModule = 'typescript-eslint' | 'eslint' | 'typescript';

   */
  tokens: null | TSESTree.Token[];

  /**
   * Caches searches for TSConfigs from project directories.
   */
  tsconfigMatchCache: CacheLike<string, string>;

  /**
   * The absolute path to the root directory for all provided `project`s.
   */
diff --git a/packages/typescript-estree/src/parser-options.ts b/packages/typescript-estree/src/parser-options.ts
  preserveNodeMaps?: boolean;

  /**
   * Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s).
   * Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s),
   * or `true` to find the nearest tsconfig.json to the file.
   * If this is provided, type information will be returned.
   */
  project?: string | string[];
  project?: string | string[] | true;

  /**
   * If you provide a glob (or globs) to the project option, you can use this option to ignore certain folders from
diff --git a/packages/typescript-estree/tests/fixtures/projectTrue/nested/deep/included.ts b/packages/typescript-estree/tests/fixtures/projectTrue/nested/deep/included.ts
 const b = true;
diff --git a/packages/typescript-estree/tests/fixtures/projectTrue/nested/included.ts b/packages/typescript-estree/tests/fixtures/projectTrue/nested/included.ts
 const b = true;
diff --git a/packages/typescript-estree/tests/fixtures/projectTrue/nested/tsconfig.json b/packages/typescript-estree/tests/fixtures/projectTrue/nested/tsconfig.json
 {
  "include": ["."]
 }
diff --git a/packages/typescript-estree/tests/fixtures/projectTrue/notIncluded.ts b/packages/typescript-estree/tests/fixtures/projectTrue/notIncluded.ts
 const c = true;
diff --git a/packages/typescript-estree/tests/lib/createParseSettings.test.ts b/packages/typescript-estree/tests/lib/createParseSettings.test.ts
 import { createParseSettings } from '../../src/parseSettings/createParseSettings';

 describe('createParseSettings', () => {
  describe('tsconfigMatchCache', () => {
    it('reuses the TSConfig match cache when called a subsequent time', () => {
      const parseSettings1 = createParseSettings('input.ts');
      const parseSettings2 = createParseSettings('input.ts');

      expect(parseSettings1.tsconfigMatchCache).toBe(
        parseSettings2.tsconfigMatchCache,
      );
    });
  });
 });
Original file line number	Diff line number	Diff line change
Expand Up		@@ -45,7 +45,7 @@ interface ParserOptions {
		lib?: string[];
		moduleResolver?: string;
		program?: import('typescript').Program;
		project?: string \| string[];
		project?: string \| string[] \| true;
JoshuaKGoldberg marked this conversation as resolved. Show resolvedHide resolved
		projectFolderIgnoreList?: string[];
		tsconfigRootDir?: string;
		warnOnUnsupportedTypeScriptVersion?: boolean;
Expand DownExpand Up		@@ -188,6 +188,9 @@ This option allows you to provide a path to your project's `tsconfig.json`. **Th
		- Accepted values:

		```js
		// find the tsconfig.json nearest each source file
		project: true,

		// path
		project: './tsconfig.json';

Expand All		@@ -198,6 +201,10 @@ This option allows you to provide a path to your project's `tsconfig.json`. **Th
		project: ['./packages/**/tsconfig.json', './separate-package/tsconfig.json'];
		```

		- If `true`, each source file's parse will find the nearest `tsconfig.json` file to that source file.

		- This is done by checking that source file's directory tree for the nearest `tsconfig.json`.

		- If you use project references, TypeScript will not automatically use project references to resolve files. This means that you will have to add each referenced tsconfig to the `project` field either separately, or via a glob.

		- Note that using wide globs `` in your `parserOptions.project` may cause performance implications. Instead of globs that use `` to recursively check all folders, prefer paths that use a single `*` at a time. For more info see [#2611](https://github.com/typescript-eslint/typescript-eslint/issues/2611).
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -174,10 +174,11 @@ interface ParseAndGenerateServicesOptions extends ParseOptions {
		preserveNodeMaps?: boolean;

		/**
		* Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s).
		* Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s),
		* or `true` to find the nearest tsconfig.json to the file.
		* If this is provided, type information will be returned.
		*/
		project?: string \| string[];
		project?: string \| string[] \| true;

		/**
		* If you provide a glob (or globs) to the project option, you can use this option to ignore certain folders from
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -18,7 +18,7 @@ module.exports = {
		parser: '@typescript-eslint/parser',
		// Added lines start
		parserOptions: {
		project:['./tsconfig.json'],
		project:true,
		tsconfigRootDir: __dirname,
		},
		// Added lines end
Expand All		@@ -36,6 +36,31 @@ In more detail:
		With that done, run the same lint command you ran before.
		You may see new rules reporting errors based on type information!

		## Specifying TSConfigs

		The `parserOptions.project` option can be turned on with either:

		- `true`: to always use `tsconfig.json`s nearest to source files
		- `string \| string[]`: any number of glob paths to match TSConfig files relative to the

		For example, if you use a specific `tsconfig.eslint.json` for linting, you'd specify:

		```js title=".eslintrc.js"
		module.exports = {
		// ...
		parserOptions: {
		project: './tsconfig.eslint.json',
		},
		// ...
		};
		```

		See [the `@typescript-eslint/parser` docs for more details](https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/parser/README.md#parseroptionsproject).

		:::note
		If your project is a multi-package monorepo, see [our docs on configuring a monorepo](./typed-linting/Monorepos.mdx).
		:::

		## FAQs

		### How is performance?
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -53,7 +53,7 @@ module.exports = {
		parserOptions: {
		tsconfigRootDir: __dirname,
		// Remove this line
		project:['./tsconfig.json'],
		project:true,
		// Add this line
		project: ['./tsconfig.eslint.json', './packages/*/tsconfig.json'],
		},
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -52,7 +52,7 @@ interface ParserOptions {
		filePath?: string;
		loc?: boolean;
		program?: Program;
		project?: string \| string[];
		project?: string \| string[] \| true;
		projectFolderIgnoreList?: (string \| RegExp)[];
		range?: boolean;
		sourceType?: SourceType;
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -3,15 +3,18 @@ import type { CacheDurationSeconds } from '@typescript-eslint/types';
		export const DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS = 30;
		const ZERO_HR_TIME: [number, number] = [0, 0];

		export interface CacheLike<Key, Value> {
		get(key: Key): Value \| void;
		set(key: Key, value: Value): this;
		}

		/**
		* A map with key-level expiration.
		*/
		export class ExpiringCache<TKey, TValue> {
		export class ExpiringCache<TKey, TValue>implements CacheLike<TKey, TValue>{
		readonly #cacheDurationSeconds: CacheDurationSeconds;
		/**
		* The mapping of path-like string to the resolved TSConfig(s)
		*/
		protected readonly map = new Map<

		readonly #map = new Map<
		TKey,
		Readonly<{
		value: TValue;
Expand All		@@ -24,7 +27,7 @@ export class ExpiringCache<TKey, TValue> {
		}

		set(key: TKey, value: TValue): this {
		this.map.set(key, {
		this.#map.set(key, {
		value,
		lastSeen:
		this.#cacheDurationSeconds === 'Infinity'
Expand All		@@ -36,7 +39,7 @@ export class ExpiringCache<TKey, TValue> {
		}

		get(key: TKey): TValue \| undefined {
		const entry = this.map.get(key);
		const entry = this.#map.get(key);
		if (entry?.value != null) {
		if (this.#cacheDurationSeconds === 'Infinity') {
		return entry.value;
Expand All		@@ -48,22 +51,14 @@ export class ExpiringCache<TKey, TValue> {
		return entry.value;
		} else {
		// key has expired - clean it up to free up memory
		this.cleanupKey(key);
		this.#map.delete(key);
		}
		}
		// no hit :'(
		return undefined;
		}

		protected cleanupKey(key: TKey): void {
		this.map.delete(key);
		}

		get size(): number {
		return this.map.size;
		}

		clear(): void {
		this.map.clear();
		this.#map.clear();
		}
		}
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2,6 +2,11 @@ import debug from 'debug';

		import { ensureAbsolutePath } from '../create-program/shared';
		import type { TSESTreeOptions } from '../parser-options';
		import {
		DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS,
		ExpiringCache,
		} from './ExpiringCache';
		import { getProjectConfigFiles } from './getProjectConfigFiles';
		import type { MutableParseSettings } from './index';
		import { inferSingleRun } from './inferSingleRun';
		import { resolveProjectList } from './resolveProjectList';
Expand All		@@ -11,10 +16,13 @@ const log = debug(
		'typescript-eslint:typescript-estree:parser:parseSettings:createParseSettings',
		);

		let TSCONFIG_MATCH_CACHE: ExpiringCache<string, string> \| null;

		export function createParseSettings(
		code: string,
		options: Partial<TSESTreeOptions> = {},
		): MutableParseSettings {
		const singleRun = inferSingleRun(options);
		const tsconfigRootDir =
		typeof options.tsconfigRootDir === 'string'
		? options.tsconfigRootDir
Expand DownExpand Up		@@ -58,8 +66,14 @@ export function createParseSettings(
		programs: Array.isArray(options.programs) ? options.programs : null,
		projects: [],
		range: options.range === true,
		singleRun: inferSingleRun(options),
		singleRun,
		tokens: options.tokens === true ? [] : null,
		tsconfigMatchCache: (TSCONFIG_MATCH_CACHE ??= new ExpiringCache(
		singleRun
		? 'Infinity'
		: options.cacheLifetime?.glob ??
		DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS,
		)),
		tsconfigRootDir,
		};

Expand DownExpand Up		@@ -95,7 +109,7 @@ export function createParseSettings(
		if (!parseSettings.programs) {
		parseSettings.projects = resolveProjectList({
		cacheLifetime: options.cacheLifetime,
		project: options.project,
		project:getProjectConfigFiles(parseSettings,options.project),
		projectFolderIgnoreList: options.projectFolderIgnoreList,
		singleRun: parseSettings.singleRun,
		tsconfigRootDir: tsconfigRootDir,
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,59 @@
		import debug from 'debug';
		import * as fs from 'fs';
		import * as path from 'path';

		import type { ParseSettings } from '.';

		const log = debug('typescript-eslint:typescript-estree:getProjectConfigFiles');

		/**
		* Checks for a matching TSConfig to a file including its parent directories,
		* permanently caching results under each directory it checks.
		*
		* @remarks
		* We don't (yet!) have a way to attach file watchers on disk, but still need to
		* cache file checks for rapid subsequent calls to fs.existsSync. See discussion
		* in https://github.com/typescript-eslint/typescript-eslint/issues/101.
		*/
		export function getProjectConfigFiles(
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		parseSettings: Pick<
		ParseSettings,
		'filePath' \| 'tsconfigMatchCache' \| 'tsconfigRootDir'
		>,
		project: string \| string[] \| true \| undefined,
		): string[] \| undefined {
		if (project !== true) {
		return project === undefined \|\| Array.isArray(project)
		? project
		: [project];
		}

		log('Looking for tsconfig.json at or above file: %s', parseSettings.filePath);
		let directory = path.dirname(parseSettings.filePath);
		const checkedDirectories = [directory];

		do {
		log('Checking tsconfig.json path: %s', directory);
		const tsconfigPath = path.join(directory, 'tsconfig.json');
		const cached =
		parseSettings.tsconfigMatchCache.get(directory) ??
		(fs.existsSync(tsconfigPath) && tsconfigPath);

		if (cached) {
		for (const directory of checkedDirectories) {
		parseSettings.tsconfigMatchCache.set(directory, cached);
		}
		return [cached];
		}

		directory = path.dirname(directory);
		checkedDirectories.push(directory);
		} while (
		directory.length > 1 &&
		directory.length >= parseSettings.tsconfigRootDir.length
		);

		throw new Error(
		`project was set to \`true\` but couldn't find any tsconfig.json relative to '${parseSettings.filePath}' within '${parseSettings.tsconfigRootDir}'.`,
		);
		}
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2,6 +2,7 @@ import type * as ts from 'typescript';

		import type { CanonicalPath } from '../create-program/shared';
		import type { TSESTree } from '../ts-estree';
		import type { CacheLike } from './ExpiringCache';

		type DebugModule = 'typescript-eslint' \| 'eslint' \| 'typescript';

Expand DownExpand Up		@@ -115,6 +116,11 @@ export interface MutableParseSettings {
		*/
		tokens: null \| TSESTree.Token[];

		/**
		* Caches searches for TSConfigs from project directories.
		*/
		tsconfigMatchCache: CacheLike<string, string>;

		/**
		* The absolute path to the root directory for all provided `project`s.
		*/
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -120,10 +120,11 @@ interface ParseAndGenerateServicesOptions extends ParseOptions {
		preserveNodeMaps?: boolean;

		/**
		* Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s).
		* Absolute (or relative to `tsconfigRootDir`) paths to the tsconfig(s),
		* or `true` to find the nearest tsconfig.json to the file.
		* If this is provided, type information will be returned.
		*/
		project?: string \| string[];
		project?: string \| string[] \| true;

		/**
		* If you provide a glob (or globs) to the project option, you can use this option to ignore certain folders from
Expand Down