Function Console

lib/internal/console/constructor.js:102–174

(options /* or: stdout, stderr, ignoreErrors = true */)

const optionsMap = new SafeWeakMap();
function Console(options /* or: stdout, stderr, ignoreErrors = true */) {
  // We have to test new.target here to see if this function is called
  // with new, because we need to define a custom instanceof to accommodate
  // the global console.
  if (new.target === undefined) {
    return ReflectConstruct(Console, arguments);
  }

  if (!options || typeof options.write === 'function') {
    options = {
      stdout: options,
      stderr: arguments[1],
      ignoreErrors: arguments[2],
    };
  }

  const {
    stdout,
    stderr = stdout,
    ignoreErrors = true,
    colorMode = 'auto',
    inspectOptions,
    groupIndentation,
  } = options;

  if (!stdout || typeof stdout.write !== 'function') {
    throw new ERR_CONSOLE_WRITABLE_STREAM('stdout');
  }
  if (!stderr || typeof stderr.write !== 'function') {
    throw new ERR_CONSOLE_WRITABLE_STREAM('stderr');
  }

  validateOneOf(colorMode, 'colorMode', ['auto', true, false]);

  if (groupIndentation !== undefined) {
    validateInteger(groupIndentation, 'groupIndentation',
                    0, kMaxGroupIndentation);
  }

  if (inspectOptions !== undefined) {
    validateObject(inspectOptions, 'options.inspectOptions');

    const inspectOptionsMap = isMap(inspectOptions) ?
      inspectOptions : new SafeMap([
        [stdout, inspectOptions],
        [stderr, inspectOptions],
      ]);

    for (const inspectOptions of MapPrototypeValues(inspectOptionsMap)) {
      if (inspectOptions.colors !== undefined &&
          options.colorMode !== undefined) {
        throw new ERR_INCOMPATIBLE_OPTION_PAIR(
          'options.inspectOptions.color', 'colorMode');
      }
    }
    optionsMap.set(this, inspectOptionsMap);
  }