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Version: 1.x

Unit Testing

The last step of this tutorial is to add some unit tests to the ApiController.

A unit test file ends with the spec.ts extension and is usually placed next to the file it is testing.

Create a new file config/test.json to set the database uri.

{  "mongodb": {    "uri": "mongodb://localhost:27017/test-my-app"  }}

Then open the file api.controller.spec.ts and replace its content.

// std// The `assert` module provides a simple set of assertion tests.import { ok, strictEqual } from 'assert';
// 3pimport { Config, createController, getHttpMethod, getPath, isHttpResponseOK } from '@foal/core';import { connect, disconnect } from 'mongoose';
// Appimport { Todo } from '../models';import { ApiController } from './api.controller';
// Define a group of tests.describe('ApiController', () => {
  let controller: ApiController;
  // Create a connection to the database before running all the tests.  before(async () => {    const uri = Config.getOrThrow('mongodb.uri', 'string');    connect(uri, { useNewUrlParser: true, useCreateIndex: true, useUnifiedTopology: true });
    await Todo.deleteMany({});  });
  // Close the database connection after running all the tests whether they succeed or failed.  after(() => disconnect());
  // Create or re-create the controller before each test.  beforeEach(() => controller = createController(ApiController));
  // Define a nested group of tests.  describe('has a "getTodos" method that', () => {
    // Define a unit test.    it('should handle requests at GET /.', () => {      // Throw an error and make the test fail if the http method of `getTodos` is not GET.      strictEqual(getHttpMethod(ApiController, 'getTodos'), 'GET');      // Throw an error and make the test fail if the path of `getTodos` is not /todos.      strictEqual(getPath(ApiController, 'getTodos'), '/todos');    });
    // Define a unit test.    it('should return an HttpResponseOK.', async () => {      // Create fake todos.      const todo1 = new Todo();      todo1.text = 'Todo 1';
      const todo2 = new Todo();      todo2.text = 'Todo 2';
      // Save the todos.      await Promise.all([,      ]);
      const response = await controller.getTodos();      ok(isHttpResponseOK(response), 'response should be an instance of HttpResponseOK.');
      const body = response.body;
      ok(Array.isArray(body), 'The body of the response should be an array.');      strictEqual(body[0].text, 'Todo 1');      strictEqual(body[1].text, 'Todo 2');    });

As a controller method returns an HttpResponse object, it is really easy to test the status and body of the response.

If the controller method takes a Context object as argument, you can instantiate one like this: new Context({ /* content of the express request object */}).

Run the tests.

npm run test

This command watches at your tests and tested files in the app/ directory. When a file is modified, it automatically recompiles and re-runs your tests.

You should now end up with this output:

Unit tests output

Congratulations! You have reached the end of this tutorial!

If you have any questions, feel free to open an issue on Github!