Function write

src/destination.ts:16–40

(chunk, encoding, callback)

  const writeable = new Writable({
    defaultEncoding: 'utf8',
    write(chunk, encoding, callback) {
      const storageProvider = options.storageProvider || GlobalContextStorageProvider;
      const formatter = options.formatter || new CloudwatchLogFormatter();

      const data = JSON.parse(chunk);
      const lambdaContext = storageProvider.getContext() || {};

      // format the combined request context and log data
      let output = formatter.format({ ...lambdaContext, ...data });

      // replace characters for proper formatting
      output = output.replace(/\n/, '\r');

      // final entry must end with carriage return
      output += '\n';

      /* istanbul ignore else */
      if (options.streamWriter) {
        options.streamWriter(output);
      } else {
        process.stdout.write(output);
      }

      callback();
    },
  });

  return writeable;