Introduction

This is a NodeJS starter project written in TypeScript that designs, creates and tests REST APIs using ExpressJS framework

Reuse

This project can be reused for other projects by switching to starter branch.

Design

The design is done before the APIs are developed using OpenAPI Spec 3.0. The swagger document should be replaced at api-docs/swagger.yml. This is loaded using the swagger-ui module at the route api-docs.

Development

Router

Express JS routers are used to route requests. A sample router would be as the following

import { add } from "./module";
const router = Router();

router.post("/add", async (req, res, next) => {
  try {
    const payload: number = add(req.body.number1, req.body.number2);
    return res.status(StatusCodes.OK).send(payload);
  } catch (err) {
    next(err);
  }
});

Module

The actual business logic that does all the processing with the given parameters, usually request body or query parameters. The actual express request or response object should not be passed into any methods of this file as parameters. This should not have anything to do with express so it can be tested using unit tests.

export function add(number1: number, number2: number): number {
    return number1 + number2;
}

Testing

Jasmine is the test framework that is used. A sample unit tests written will be as the following

import { add } from "../math/module";

describe("Math tests", () => {
    it("Should add 2 numbers", () => {
        expect( add(2, 4) ).toBe(6);
    });
})

The file should end in .spec.ts for it to be picked up by jasmine.

A more common tests which interacts with the database uses mongo-unit as the in memory database would invoke startDBServer from spec/utils/server.ts in beforeAll and stopDBServer in afterAll of the spec

import { createUser, getUsers } from "../../admin/module";
import { startDBServer, stopDBServer } from "../utils/server"

describe("User creation tests", () => {
    beforeAll(async () => {
        await startDBServer();
    })

    it("Should create a user", async () => {
        const testUserPayload = { name: "Test User", email: "[email protected]" };
        await createUser(testUserPayload);
        const users = await getUsers();
        expect(users.length).toBe(1);
        const [firstUser] = users;
        expect(firstUser.id).not.toBeNull();
        expect(firstUser.name).toBe(testUserPayload.name);
        expect(firstUser.email).toBe(testUserPayload.email);
    })

    afterAll(async () => {
        await stopDBServer();
    })
})