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📄 createProjectService.ts

📊 Analysis Summary

Metric	Count
🔧 Functions	47
📦 Imports	3
📊 Variables & Constants	6
🔄 Re-exports	1
📐 Interfaces	2
📑 Type Aliases	1

📚 Table of Contents

• Imports
• Variables & Constants
• Re-exports
• Functions
• Interfaces
• Type Aliases

🛠️ File Location:

📂 packages/project-service/src/createProjectService.ts

📦 Imports

Name	Source
ProjectServiceOptions	@typescript-eslint/types
debug	debug
getParsedConfigFileFromTSServer	./getParsedConfigFileFromTSServer.js

---

Variables & Constants

Name	Type	Kind	Value	Exported
DEFAULT_PROJECT_MATCHED_FILES_THRESHOLD	8	const	8	✗
options	any	const	`{
defaultProject: 'tsconfig.json',
...optionsRaw,
}`	✗
tsserver	any	const	require('typescript/lib/tsserverlibrary') as typeof ts	✗
system	ts.server.ServerHost	const	`{
...tsserver.sys,
clearImmediate,
clearTimeout,
setImmediate,
setTimeout,
watchDirectory: createStubFileWatcher,
watchFile: createStubFileWatcher,

// We stop loading any TypeScript plugins by default, to prevent them from attaching disk watchers
// See https://github.com/typescript-eslint/typescript-eslint/issues/9905
...(!options.loadTypeScriptPlugins && {
  require: () => ({
    error: {
      message:
        'TypeScript plugins are not required when using parserOptions.projectService.',
    },
    module: undefined,
  }),
}),

}| ✗ | |logger|ts.server.Logger| const |{ close: doNothing, endGroup: doNothing, getLogFileName: (): undefined => undefined, // The debug library doesn't use levels without creating a namespace for each. // Log levels are not passed to the writer so we wouldn't be able to forward // to a respective namespace. Supporting would require an additional flag for // granular control. Defaulting to all levels for now. hasLevel: (): boolean => true, info(s) { this.msg(s, tsserver.server.Msg.Info); }, loggingEnabled: (): boolean => // if none of the debug namespaces are enabled, then don't enable logging in tsserver logTsserverInfo.enabled || logTsserverErr.enabled || logTsserverPerf.enabled, msg: (s, type) => { switch (type) { case tsserver.server.Msg.Err: logTsserverErr(s); break; case tsserver.server.Msg.Perf: logTsserverPerf(s); break; default: logTsserverInfo(s); } }, perftrc(s) { this.msg(s, tsserver.server.Msg.Perf); }, startGroup: doNothing, }| ✗ | |service|any| const |new tsserver.server.ProjectService({ cancellationToken: { isCancellationRequested: (): boolean => false }, eventHandler: logTsserverEvent.enabled ? (e): void => { logTsserverEvent(e); } : undefined, host: system, jsDocParsingMode, logger, session: undefined, useInferredProjectPerProjectRoot: false, useSingleInferredProject: false, })` | ✗ |

---

Re-exports

Type	Source	Exported Names
named	@typescript-eslint/types	ProjectServiceOptions

---

Functions

doNothing(): void

Code

(): void => {}

• Return Type: void

createStubFileWatcher(): ts.FileWatcher

Code

(): ts.FileWatcher => ({
  close: doNothing,
})

• Return Type: ts.FileWatcher

`createProjectService({

jsDocParsingMode, options: optionsRaw = {}, tsconfigRootDir, }: CreateProjectServiceSettings): ProjectServiceAndMetadata`

Code

export function createProjectService({
  jsDocParsingMode,
  options: optionsRaw = {},
  tsconfigRootDir,
}: CreateProjectServiceSettings = {}): ProjectServiceAndMetadata {
  const options = {
    defaultProject: 'tsconfig.json',
    ...optionsRaw,
  };

  // We import this lazily to avoid its cost for users who don't use the service
  // TODO: Once we drop support for TS<5.3 we can import from "typescript" directly
  // eslint-disable-next-line @typescript-eslint/no-require-imports
  const tsserver = require('typescript/lib/tsserverlibrary') as typeof ts;

  // TODO: see getWatchProgramsForProjects
  // We don't watch the disk, we just refer to these when ESLint calls us
  // there's a whole separate update pass in maybeInvalidateProgram at the bottom of getWatchProgramsForProjects
  // (this "goes nuclear on TypeScript")
  const system: ts.server.ServerHost = {
    ...tsserver.sys,
    clearImmediate,
    clearTimeout,
    setImmediate,
    setTimeout,
    watchDirectory: createStubFileWatcher,
    watchFile: createStubFileWatcher,

    // We stop loading any TypeScript plugins by default, to prevent them from attaching disk watchers
    // See https://github.com/typescript-eslint/typescript-eslint/issues/9905
    ...(!options.loadTypeScriptPlugins && {
      require: () => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      }),
    }),
  };

  const logger: ts.server.Logger = {
    close: doNothing,
    endGroup: doNothing,
    getLogFileName: (): undefined => undefined,
    // The debug library doesn't use levels without creating a namespace for each.
    // Log levels are not passed to the writer so we wouldn't be able to forward
    // to a respective namespace.  Supporting would require an additional flag for
    // granular control.  Defaulting to all levels for now.
    hasLevel: (): boolean => true,
    info(s) {
      this.msg(s, tsserver.server.Msg.Info);
    },
    loggingEnabled: (): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled,
    msg: (s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    },
    perftrc(s) {
      this.msg(s, tsserver.server.Msg.Perf);
    },
    startGroup: doNothing,
  };

  log('Creating Project Service with: %o', options);

  const service = new tsserver.server.ProjectService({
    cancellationToken: { isCancellationRequested: (): boolean => false },
    eventHandler: logTsserverEvent.enabled
      ? (e): void => {
          logTsserverEvent(e);
        }
      : undefined,
    host: system,
    jsDocParsingMode,
    logger,
    session: undefined,
    useInferredProjectPerProjectRoot: false,
    useSingleInferredProject: false,
  });

  service.setHostConfiguration({
    preferences: {
      includePackageJsonAutoImports: 'off',
    },
  });

  log('Enabling default project: %s', options.defaultProject);

  const configFile = getParsedConfigFileFromTSServer(
    tsserver,
    options.defaultProject,
    !!optionsRaw.defaultProject,
    tsconfigRootDir,
  );

  if (configFile) {
    service.setCompilerOptionsForInferredProjects(
      // NOTE: The inferred projects API is not intended for source files when a tsconfig
      // exists. There is no API that generates an InferredProjectCompilerOptions suggesting
      // it is meant for hard coded options passed in. Hard asserting as a work around.
      // See https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/server/protocol.ts#L1904
      configFile.options as ts.server.protocol.InferredProjectCompilerOptions,
    );
  }

  return {
    allowDefaultProject: options.allowDefaultProject,
    lastReloadTimestamp: performance.now(),
    maximumDefaultProjectFileMatchCount:
      options.maximumDefaultProjectFileMatchCount_THIS_WILL_SLOW_DOWN_LINTING ??
      DEFAULT_PROJECT_MATCHED_FILES_THRESHOLD,
    service,
  };
}

• JSDoc:

  /**
   * Creates a new Project Service instance, as well as metadata on its creation.
   * @param settings Settings to create a new Project Service instance.
   * @returns A new Project Service instance, as well as metadata on its creation.
   * @example
   * ```ts
   * import { createProjectService } from '@typescript-eslint/project-service';
   *
   * const { service } = createProjectService();
   *
   * service.openClientFile('index.ts');
   * ```
   */
  

• Parameters:

• { jsDocParsingMode, options: optionsRaw = {}, tsconfigRootDir, }: CreateProjectServiceSettings
• Return Type: ProjectServiceAndMetadata
• Calls:
• require
• this.msg
• logTsserverErr
• logTsserverPerf
• logTsserverInfo
• log
• logTsserverEvent
• service.setHostConfiguration
• getParsedConfigFileFromTSServer (from ./getParsedConfigFileFromTSServer.js)
• service.setCompilerOptionsForInferredProjects
• performance.now
• Internal Comments:

  // We import this lazily to avoid its cost for users who don't use the service (x2)
  // TODO: Once we drop support for TS<5.3 we can import from "typescript" directly (x2)
  // eslint-disable-next-line @typescript-eslint/no-require-imports (x2)
  // TODO: see getWatchProgramsForProjects (x2)
  // We don't watch the disk, we just refer to these when ESLint calls us (x2)
  // there's a whole separate update pass in maybeInvalidateProgram at the bottom of getWatchProgramsForProjects (x2)
  // (this "goes nuclear on TypeScript") (x2)
  // We stop loading any TypeScript plugins by default, to prevent them from attaching disk watchers
  // See https://github.com/typescript-eslint/typescript-eslint/issues/9905
  // The debug library doesn't use levels without creating a namespace for each. (x2)
  // Log levels are not passed to the writer so we wouldn't be able to forward (x2)
  // to a respective namespace.  Supporting would require an additional flag for (x2)
  // granular control.  Defaulting to all levels for now. (x2)
  // if none of the debug namespaces are enabled, then don't enable logging in tsserver (x4)
  // NOTE: The inferred projects API is not intended for source files when a tsconfig (x3)
  // exists. There is no API that generates an InferredProjectCompilerOptions suggesting (x3)
  // it is meant for hard coded options passed in. Hard asserting as a work around. (x3)
  // See https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/server/protocol.ts#L1904 (x3)
  

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

require(): { error: { message: string; }; module: any; }

Code

() => ({
        error: {
          message:
            'TypeScript plugins are not required when using parserOptions.projectService.',
        },
        module: undefined,
      })

• Return Type: { error: { message: string; }; module: any; }

getLogFileName(): undefined

Code

(): undefined => undefined

• Return Type: undefined

hasLevel(): boolean

Code

(): boolean => true

• Return Type: boolean

loggingEnabled(): boolean

Code

(): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled

• Return Type: boolean
• Internal Comments:

  // if none of the debug namespaces are enabled, then don't enable logging in tsserver
  

msg(s: any, type: any): void

Code

(s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    }

• Parameters:
• s: any
• type: any
• Return Type: void
• Calls:
• logTsserverErr
• logTsserverPerf
• logTsserverInfo

getLogFileName(): undefined

Code

(): undefined => undefined

• Return Type: undefined

hasLevel(): boolean

Code

(): boolean => true

• Return Type: boolean

loggingEnabled(): boolean

Code

(): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled

• Return Type: boolean
• Internal Comments:

  // if none of the debug namespaces are enabled, then don't enable logging in tsserver
  

msg(s: any, type: any): void

Code

(s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    }

• Parameters:
• s: any
• type: any
• Return Type: void
• Calls:
• logTsserverErr
• logTsserverPerf
• logTsserverInfo

getLogFileName(): undefined

Code

(): undefined => undefined

• Return Type: undefined

hasLevel(): boolean

Code

(): boolean => true

• Return Type: boolean

loggingEnabled(): boolean

Code

(): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled

• Return Type: boolean
• Internal Comments:

  // if none of the debug namespaces are enabled, then don't enable logging in tsserver
  

msg(s: any, type: any): void

Code

(s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    }

• Parameters:
• s: any
• type: any
• Return Type: void
• Calls:
• logTsserverErr
• logTsserverPerf
• logTsserverInfo

getLogFileName(): undefined

Code

(): undefined => undefined

• Return Type: undefined

hasLevel(): boolean

Code

(): boolean => true

• Return Type: boolean

loggingEnabled(): boolean

Code

(): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled

• Return Type: boolean
• Internal Comments:

  // if none of the debug namespaces are enabled, then don't enable logging in tsserver
  

msg(s: any, type: any): void

Code

(s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    }

• Parameters:
• s: any
• type: any
• Return Type: void
• Calls:
• logTsserverErr
• logTsserverPerf
• logTsserverInfo

getLogFileName(): undefined

Code

(): undefined => undefined

• Return Type: undefined

hasLevel(): boolean

Code

(): boolean => true

• Return Type: boolean

loggingEnabled(): boolean

Code

(): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled

• Return Type: boolean
• Internal Comments:

  // if none of the debug namespaces are enabled, then don't enable logging in tsserver
  

msg(s: any, type: any): void

Code

(s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    }

• Parameters:
• s: any
• type: any
• Return Type: void
• Calls:
• logTsserverErr
• logTsserverPerf
• logTsserverInfo

getLogFileName(): undefined

Code

(): undefined => undefined

• Return Type: undefined

hasLevel(): boolean

Code

(): boolean => true

• Return Type: boolean

loggingEnabled(): boolean

Code

(): boolean =>
      // if none of the debug namespaces are enabled, then don't enable logging in tsserver
      logTsserverInfo.enabled ||
      logTsserverErr.enabled ||
      logTsserverPerf.enabled

• Return Type: boolean
• Internal Comments:

  // if none of the debug namespaces are enabled, then don't enable logging in tsserver
  

msg(s: any, type: any): void

Code

(s, type) => {
      switch (type) {
        case tsserver.server.Msg.Err:
          logTsserverErr(s);
          break;
        case tsserver.server.Msg.Perf:
          logTsserverPerf(s);
          break;
        default:
          logTsserverInfo(s);
      }
    }

• Parameters:
• s: any
• type: any
• Return Type: void
• Calls:
• logTsserverErr
• logTsserverPerf
• logTsserverInfo

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

isCancellationRequested(): boolean

Code

(): boolean => false

• Return Type: boolean

---

Interfaces

ProjectServiceAndMetadata

Interface Code

export interface ProjectServiceAndMetadata {
  /**
   * Files allowed to be loaded from the default project, if any were specified.
   */
  allowDefaultProject: string[] | undefined;

  /**
   * The performance.now() timestamp of the last reload of the project service.
   */
  lastReloadTimestamp: number;

  /**
   * The maximum number of files that can be matched by the default project.
   */
  maximumDefaultProjectFileMatchCount: number;

  /**
   * The created TypeScript Project Service instance.
   */
  service: TypeScriptProjectService;
}

Properties

Name	Type	Optional	Description
allowDefaultProject	string[] | undefined	✗
lastReloadTimestamp	number	✗
maximumDefaultProjectFileMatchCount	number	✗
service	TypeScriptProjectService	✗

CreateProjectServiceSettings

Interface Code

export interface CreateProjectServiceSettings {
  /**
   * Granular options to configure the project service.
   */
  options?: ProjectServiceOptions;

  /**
   * How aggressively (and slowly) to parse JSDoc comments.
   */
  jsDocParsingMode?: ts.JSDocParsingMode;

  /**
   * Root directory for the tsconfig.json file, if not the current directory.
   */
  tsconfigRootDir?: string;
}

Properties

Name	Type	Optional	Description
options	ProjectServiceOptions	✓
jsDocParsingMode	ts.JSDocParsingMode	✓
tsconfigRootDir	string	✓

---

Type Aliases

TypeScriptProjectService

/* * Shortcut type to refer to TypeScript's server ProjectService. /

type TypeScriptProjectService = ts.server.ProjectService;

---