Function processAsyncCmd

ng-dev/utils/child-process.ts:183–250

* Process the ChildProcess object created by an async command.

(
  command: string,
  options: CommonCmdOpts,
  childProcess: _ChildProcess,
)

 * Process the ChildProcess object created by an async command.
 */
function processAsyncCmd(
  command: string,
  options: CommonCmdOpts,
  childProcess: _ChildProcess,
): Promise<SpawnResult> {
  return new Promise((resolve, reject) => {
    let logOutput = '';
    let stdout = '';
    let stderr = '';

    Log.debug(`Executing command: ${sanitize(command)}`);

    childProcess.on('error', (err) => {
      reject(err);
    });

    // If provided, write `input` text to the process `stdin`.
    if (options.input !== undefined) {
      assert(
        childProcess.stdin,
        'Cannot write process `input` if there is no pipe `stdin` channel.',
      );
      childProcess.stdin.write(options.input);
      childProcess.stdin.end();
    }

    // Capture the stdout separately so that it can be passed as resolve value.
    // This is useful if commands return parsable stdout.
    childProcess.stderr?.on('data', (message) => {
      stderr += message;
      logOutput += message;
      // If console output is enabled, print the message directly to the stderr. Note that
      // we intentionally print all output to stderr as stdout should not be polluted.
      if (options.mode === undefined || options.mode === 'enabled') {
        process.stderr.write(sanitize(String(message)));
      }
    });

    childProcess.stdout?.on('data', (message) => {
      stdout += message;
      logOutput += message;
      // If console output is enabled, print the message directly to the stderr. Note that
      // we intentionally print all output to stderr as stdout should not be polluted.
      if (options.mode === undefined || options.mode === 'enabled') {
        process.stderr.write(sanitize(String(message)));
      }
    });

    // The `close` event is used because the process is guaranteed to have completed writing to
    // stdout and stderr, using the `exit` event can cause inconsistent information in stdout and
    // stderr due to a race condition around exiting.
    childProcess.on('close', (exitCode, signal) => {
      const exitDescription = exitCode !== null ? `exit code "${exitCode}"` : `signal "${signal}"`;
      const status = statusFromExitCodeAndSignal(exitCode, signal);
      const printFn = status !== 0 && options.mode === 'on-error' ? Log.error : Log.debug;
      printFn(`Command "${sanitize(command)}" completed with ${exitDescription}.`);
      printFn(`Process output: \n${sanitize(logOutput)}`);