nextjs-api-utils

This package contains some API utilities to be used with Next.js

Utilities

chainMiddleware

This utility can be used to chain express like middleware. Usage is as follows

import { chainMiddleware } from 'nextjs-api-utils';

export default async (req, res) => {
  await chainMiddleware(req, res, [
    /** middleware functions */
  ], async (req, res) => {
    /** actual API request body */
  });
}

answer

This function can be used to generate a standardized answer from a next.js API route. It can be used as follows:

import { answer, ErrorCodes } from 'nextjs-api-utils';

export default (req, res) => {
  return answer(req, res, {
    statusCode: 400,
    errorCode: ErrorCodes.INTERNAL_SERVER_ERROR,
    data: { foo: 'bar' },
    meta: { foo: 'baz' }
  });
}

This will result in the HTTP request returning a 400 status code and the following body

{
  "success": false,
  "errorCode": "internal_server_error",
  "data": { "foo": "bar" },
  "meta": {
    "time": "2021-02-09T17:23:35.775Z",
    "foo": "baz"
  }
}

redirect

This method can be used to redirect to a new page from an API request.

import { redirect, ErrorCodes } from 'nextjs-api-utils';

export default (req, res) => {
  return redirect(req, res, {
    redirectTo: {
      url: '/',
      query: { foo: 'bar' }
    },
    statusCode: 400,
    errorCode: ErrorCodes.BAD_REQUEST,
  });
}

This will redirect the user using a 303 HTTP status to the following path /?foo=bar&statusCode=400&errorCode=bad_request. The additional query parameters are added as this is intended to be used when an API request fails when directly accessed by a user.

redirectOrAnswer

This method is a combination of answer and redirect. It will use the normalized answer when a accept header is present containing application/json. Otherwise it will redirect the user using the provided parameters. Usage is almost identical to the answer method with the addition of the redirectTo, onBeforeAnswer and onBeforeRedirect options.

Middlewares

For usage with chainMiddleware.

attempt

This middleware will wrap the API body in a try-catch statement. Upon failing it will use redirectOrAnswer with a status code of 500. The "on error" behavior of this can be customized by calling setAttemptErrorHandler.

import { setAttemptErrorHandler, redirectOrAnswer } from 'nextjs-api-utils';
setAttemptErrorHandler((req, res, error) => {
  return redirectOrAnswer({ ... })
});

isMethod

This middleware can be used to check the incoming HTTP method before executing the API body. The on fail behavior of this middleware can be customized using setIsMethodErrorHandler