Function readConfig

packages/node/src/typescript.ts:379–440

* Load TypeScript configuration.

(configFileName: string)

   * Load TypeScript configuration.
   */
  function readConfig(configFileName: string): _ts.ParsedCommandLine {
    let config: any = { compilerOptions: {} };
    const basePath = normalizeSlashes(dirname(configFileName));

    // Read project configuration when available.
    if (configFileName) {
      const result = ts.readConfigFile(configFileName, readFile);

      // Return diagnostics.
      if (result.error) {
        const errorResult = {
          errors: [result.error],
          fileNames: [],
          options: {},
        };
        const configDiagnosticList = filterDiagnostics(
          errorResult.errors,
          ignoreDiagnostics
        );
        // Render the configuration errors.
        reportTSError(configDiagnosticList, true);
        return errorResult;
      }

      config = result.config;
    }

    // Remove resolution of "files".
    if (!options.files) {
      config.files = [];
      config.include = [];
    }

    // Override default configuration options `ts-node` requires.
    config.compilerOptions = Object.assign(
      {},
      config.compilerOptions,
      options.compilerOptions,
      TS_NODE_COMPILER_OPTIONS
    );

    fixConfig(config, options.nodeVersionMajor);

    const configResult = ts.parseJsonConfigFileContent(
      config,
      ts.sys,
      basePath,
      undefined,
      configFileName
    );

    if (configFileName) {
      const configDiagnosticList = filterDiagnostics(
        configResult.errors,
        ignoreDiagnostics
      );
      // Render the configuration errors.
      reportTSError(configDiagnosticList, configResult.options.noEmitOnError);