Function captureLogOutputForCommand

ng-dev/utils/logging.ts:124–174

(argv: Arguments)

 * middleware of yargs to enable the file logging before the rest of the command parsing and
 * response is executed.
 */
export async function captureLogOutputForCommand(argv: Arguments) {
  // TODO(josephperrott): remove this guard against running multiple times after
  //   https://github.com/yargs/yargs/issues/2223 is fixed
  if (logStream !== undefined) {
    return;
  }
  const repoDir = determineRepoBaseDirFromCwd();
  const logFilePath = join(repoDir, '.ng-dev.log');
  if (existsSync(logFilePath) && lstatSync(logFilePath).isSymbolicLink()) {
    throw new Error(
      'Security Violation: .ng-dev.log is a symbolic link. ' +
        'To prevent arbitrary file write, execution is aborted.',
    );
  }
  logStream = createWriteStream(logFilePath, {encoding: 'utf-8'});

  /** The date time used for timestamping when the command was invoked. */
  const now = new Date();
  /** Header line to separate command runs in log files. */
  const headerLine = Array(100).fill('#').join('');
  appendToLogFile(
    undefined,
    `${headerLine}\nCommand: ${argv.$0} ${argv._.join(' ')}\nRan at: ${now}\n`,
  );

  // When the command is completed, write the logged output to the appropriate log files
  registerCompletedFunction(async (error) => {
    if (error instanceof Error) {
      appendToLogFile(LogLevel.ERROR, error.message);
      const stack = error.stack?.split('\n') ?? [];
      for (const line of stack) {
        appendToLogFile(LogLevel.ERROR, line);
      }
    }
    appendToLogFile(
      undefined,
      `\n\nCommand ran in ${new Date().getTime() - now.getTime()}ms\nExit Code: ${process.exitCode}\n`,
    );
    logStream!.end(() => {
      // For failure codes greater than 1, the new logged lines should be written to a specific log
      // file for the command run failure.
      if (process.exitCode !== 0) {
        const errorLogFileName = `.ng-dev.err-${now.getTime()}.log`;
        console.error(
          `Exit code: ${process.exitCode}.\nWriting full log to ${join(repoDir, errorLogFileName)}`,
        );
        copyFileSync(logFilePath, join(repoDir, errorLogFileName));
      }
    });
  });
}

/** Write the provided text to the log file, prepending each line with the log level.  */