README.md

Nodejs Express base API

This is a boilerplate application for building REST APIs in Node.js using ES6, Express and PostgreSQL.

Getting Started

Installation

1. Clone the repository with https://github.com/dendyjuliano/boilerplate-nodejs-expres.git
2. Install the dependencies with yarn install (click here if you don't have Yarn installed
3. Setup the database on src/config/postgres.js and config information on env.example

Scripts

This boilerplate comes with a collection of npm scripts to make your life easier, you'll run them with npm run <script name> or yarn <script name>:

• start: Run the application in development mode

Project Structure

src\
 |--config\         # Environment variables and configuration related things
 |--controllers\    # Route controllers (controller layer)
 |--db\
  |--migrations\    # Database migrations
  |--models\        # Database models
  |--seeders\       #
 |--routes\         # Routes
 |--services\       # Business logic (service layer)
 |--utils\          # Utility classes and functions
 |--app.js          # App entry point \ Express app

Database

This app uses Sequelize - an Object-Relational Mapper to maps object syntax into Postgres database, and Sequelize CLI package to manage sequelize.

There are 2 ways to run sequelize-cli.

# Method 1: Use sequelize global
npm install -g sequelize-cli

sequelize db:migrate

# Method 2
node_modules/.bin/sequelize db:migrate

Error Handling

The app has a centralized error handling mechanism.

Controllers should try to catch the errors and forward them to the error handling middleware (by calling next(error)). For convenience, you can also wrap the controller inside the catchAsync utility wrapper, which forwards the error.

const catchAsync = require("../utils/catchAsync");

const controller = catchAsync(async (req, res) => {
  // this error will be forwarded to the error handling middleware
  throw new Error("Something wrong happened");
});

The error handling middleware sends an error response, which has the following format:

{
  "code": 404,
  "message": "Not found"
}

When running in development mode, the error response also contains the error stack.

The app has a utility ApiError class to which you can attach a response code and a message, and then throw it from anywhere (catchAsync will catch it).

For example, if you are trying to get a user from the DB who is not found, and you want to send a 404 error, the code should look something like:

// user.controller.js
const httpStatus = require("http-status");
const ApiError = require("../utils/ApiError");

const getUser = catchAsync(async (req, res) => {
  const user = await userService.getUserById(req.params.userId);

  if (!user) {
    throw new ApiError(httpStatus.NOT_FOUND, "User not found");
  }

  res.send({ user });
});