Method _executeSubCommand

lib/command.js:1215–1358

* Execute a sub-command executable. * * @private

(subcommand, args)

   */

  _executeSubCommand(subcommand, args) {
    args = args.slice();
    const sourceExt = ['.js', '.ts', '.tsx', '.mjs', '.cjs'];

    function findFile(baseDir, baseName) {
      // Look for specified file
      const localBin = path.resolve(baseDir, baseName);
      if (fs.existsSync(localBin)) return localBin;

      // Stop looking if candidate already has an expected extension.
      if (sourceExt.includes(path.extname(baseName))) return undefined;

      // Try all the extensions.
      const foundExt = sourceExt.find((ext) =>
        fs.existsSync(`${localBin}${ext}`),
      );
      if (foundExt) return `${localBin}${foundExt}`;

      return undefined;
    }

    // Not checking for help first. Unlikely to have mandatory and executable, and can't robustly test for help flags in external command.
    this._checkForMissingMandatoryOptions();
    this._checkForConflictingOptions();

    // executableFile and executableDir might be full path, or just a name
    let executableFile =
      subcommand._executableFile || `${this._name}-${subcommand._name}`;
    let executableDir = this._executableDir || '';
    if (this._scriptPath) {
      let resolvedScriptPath; // resolve possible symlink for installed npm binary
      try {
        resolvedScriptPath = fs.realpathSync(this._scriptPath);
      } catch {
        resolvedScriptPath = this._scriptPath;
      }
      executableDir = path.resolve(
        path.dirname(resolvedScriptPath),
        executableDir,
      );
    }

    // Look for a local file in preference to a command in PATH.
    if (executableDir) {
      let localFile = findFile(executableDir, executableFile);

      // Legacy search using prefix of script name instead of command name
      if (!localFile && !subcommand._executableFile && this._scriptPath) {
        const legacyName = path.basename(
          this._scriptPath,
          path.extname(this._scriptPath),
        );
        if (legacyName !== this._name) {
          localFile = findFile(
            executableDir,
            `${legacyName}-${subcommand._name}`,
          );
        }