Function formatError

lib/internal/util/inspect.js:1933–2043

(err, constructor, tag, ctx, keys)

}

function formatError(err, constructor, tag, ctx, keys) {
  let message, name, stack;
  try {
    stack = getStackString(ctx, err);
  } catch {
    return ObjectPrototypeToString(err);
  }

  let messageIsGetterThatThrows = false;
  try {
    message = err.message;
  } catch {
    messageIsGetterThatThrows = true;
  }
  let nameIsGetterThatThrows = false;
  try {
    name = err.name;
  } catch {
    nameIsGetterThatThrows = true;
  }

  if (!ctx.showHidden && keys.length !== 0) {
    const index = ArrayPrototypeIndexOf(keys, 'stack');
    if (index !== -1) {
      ArrayPrototypeSplice(keys, index, 1);
    }

    if (!messageIsGetterThatThrows) {
      const index = ArrayPrototypeIndexOf(keys, 'message');
      // Only hide the property if it's a string and if it's part of the original stack
      if (index !== -1 && (typeof message !== 'string' || StringPrototypeIncludes(stack, message))) {
        ArrayPrototypeSplice(keys, index, 1);
      }
    }

    if (!nameIsGetterThatThrows) {
      const index = ArrayPrototypeIndexOf(keys, 'name');
      // Only hide the property if it's a string and if it's part of the original stack
      if (index !== -1 && (typeof name !== 'string' || StringPrototypeIncludes(stack, name))) {
        ArrayPrototypeSplice(keys, index, 1);
      }
    }
  }
  name ??= 'Error';

  if (ObjectPrototypeHasOwnProperty(err, 'cause') &&
      (keys.length === 0 || !ArrayPrototypeIncludes(keys, 'cause'))) {
    ArrayPrototypePush(keys, 'cause');
  }

  // Print errors aggregated into AggregateError
  try {
    const errors = err.errors;
    if (ArrayIsArray(errors) && ObjectPrototypeHasOwnProperty(err, 'errors') &&
      (keys.length === 0 || !ArrayPrototypeIncludes(keys, 'errors'))) {
      ArrayPrototypePush(keys, 'errors');
    }
  } catch {