Errors

Nixle provides a simple way to throw exceptions.

Overview

To throw an exception in Nixle, you can use the createError function. This function accepts a string as the message and an optional second parameter as the status code or an object with the following properties:

• message - A string with additional information. Example: You are unauthorized!.
• statusCode - An HTTP status code. Example: 401. You can use the StatusCode enum from nixle.
• code - Custom error code. Example: USER_UNAUTHORIZED_ERROR.
• details - An object with additional details. Example: { userId: 1 }.

TIP

To set the status code, you can use the StatusCode enum.

import { createError, StatusCode } from 'nixle';

export const usersService = createService(() => {
  const getUsers = async () => {
    if (Math.random() > 0.5) {
      if (Math.random() > 0.5) {
        throw createError('You are unauthorized!');
      } else {
        throw createError('You are unauthorized!', StatusCode.FORBIDDEN);
      }
    } else {
      throw createError({
        message: 'You are unauthorized!',
        statusCode: StatusCode.UNAUTHORIZED,
        code: 'USER_UNAUTHORIZED_ERROR',
        details: { userId: 1 },
      });
    }

    // This code will never be executed.
    return ['John', 'Jane'];
  };

  return { getUsers };
});

Check error

To check an error, you can use the isNixleError function. This function takes an error and returns a boolean.

import { createService, createError, isNixleError } from 'nixle';

const usersService = createService('users', () => {
  const getUsers = async () => {
    try {
      throw createError('You are unauthorized!');
    } catch (error) {
      if (isNixleError(error)) {
        // Handle Nixle error.
      } else {
        // Handle another error.
      }
    }
  };

  return { getUsers };
});