Node test wrapper

Node test wrapper is an elegant and scalable solution for HTTP testing in Node.js. The basic idea is creation of a single object that encapsulates all the logic needed to make HTTP assertions on a Node app. Crucially, this solves the problem of other desired behaviors like authentication. Should the need arise to change or modify the HTTP assertion library or logic only the wrapper needs to be modified.

Quick start

• Install node-test-wrapper npm package globally

    npm install node-test-wrapper -g
  

  or

    yarn global add node-test-wrapper
  

• On your project folder run app wrapper CLI

    node-test-wrapper
  

or use shorthand

    test-wrapper

• Select the javascript version of the wrapper to be generated

  

• Select the type of authentication that your application uses

  

• Specify the path for the generated wrapper

  

  The wrapper is generated and placed on the path you chose

  

• Customize the generated wrapper to suit the specifics of your application

  The generated wrapper has several stubs that need to be updated:

  • ../path/to/your/app

    Update the import with the actual path to your app. For example ../../src/app. As a side note, there is merit in avoiding the creation of a server in the application definition. Tools like SuperTest and Chai HTTP will do this automatically preventing problems with application port when executing tests.

  • login()

    Based on the type of authentication your application uses, specify how the authentication parameter will be generated when this function is called with a user object.

  • loginRandom()

    Similar to login() but in this case the generated authentication parameter relies on a randomly generated or selected user.

  • logout()

    This simply specifies how the authentication parameter is reset/removed. The default logic should suffice.

  • preRequest()

    This function is triggered every time before the wrapper makes a request. The default logic adds the authentication parameter to the request object if it exists i.e. if login() or loginRandom() were previously called and logout() was not. For example, setting the authorization header in token-based authentication. More pre-request logic can be added but it is crucial that the default logic is retained or modified in such a way that it retains its primary purpose.

  • HTTP methods

    When making HTTP assertions these methods are the methods that should be triggered. Under the hood, they call the respective HTTP methods on the SuperAgent instance. This allows for pre-request logic (defined in preRequest()) to be triggered to add any desired behaviors. The most commonly used HTTP methods are available out of the box but more can be added as and when the need arises.

• Use the wrapper on your tests

  • Import the wrapper on your test file
  • Make HTTP assertions via the wrapper
  • Where authentication is required invoke login(), loginRandom() or logout() based on the desired behavior
  • Add any other desired behaviors as functions on the wrapper. Invoke the functions as and when the behaviors are required as is the case with authentication

Read this medium article for more details on the the solution.

Examples

The examples below may not make everything crystal clear. Go through examples for more elaborate full application illustrations. On all the examples test/testUtils/app.js is the app wrapper.

ES5

Wrapper

// test/testUtils/app.js

var supertest = require('supertest');
var appDef = require('../../src/app');

var User = require('../../src/models').User;
var generateAuthToken = require('../../src/utils').generateAuthToken;

var app = {
  client: supertest(appDef),

  token: null,

  login: function(user, done) {
    generateAuthToken(user, function(err, token) {
      app.token = token;
      return err ? done(err) : done(null);
    });
  },

  loginRandom: function(done) {
    // get a random user - random is just an arbitrary function to get one user
    var user = User.random();

    generateAuthToken(user, function(err, token) {
      app.token = token;
      return err ? done(err) : done(null, user);
    });
  },

  logout: function() {
    app.token = null;
  },

  preRequest: function(request) {
    return app.token ? request.set('authorization', app.token) : request;
  },

  get: function(url) {
    var req = app.client.get(url);

    return app.preRequest(req);
  },

  post: function(url) {
    var req = app.client.post(url);

    return app.preRequest(req);
  },

  put: function(url) {
    var req = app.client.put(url);

    return app.preRequest(req);
  },

  patch: function(url) {
    var req = app.client.patch(url);

    return app.preRequest(req);
  },

  delete: function(url) {
    var req = app.client.delete(url);

    return app.preRequest(req);
  }
};

module.exports = app;

Test

// test/article.spec.js

var app = require('./testUtils/app');

describe('Articles', function() {
  describe('GET', function() {
    it('should not allow unauthenticated users to list all articles', function(done) {
      app.get('/articles').expect(401, done);
    });

    it('should allow authenticated users to list all articles', function(done) {
      app.loginRandom(function() {
        app.get('/articles').then(function(res) {
          expect(res.body.articles).toEqual('All articles');
          app.logout();
          done();
        });
      });
    });
  });
});

ES6

Wrapper

// test/testUtils/app.js

import supertest from 'supertest';
import appDef from '../../src/app';

const { generateAuthToken } = require('../../src/utils');
const { User } = require('../../src/models');

class App {
  constructor() {
    this.client = supertest(appDef);
    this.token = null;
  }

  async login(user) {
    this.token = await generateAuthToken(user);
  }

  async loginRandom() {
    // get a random user - random is just an arbitrary function to get one user
    const user = User.random();

    this.token = await generateAuthToken(user);

    return user;
  }

  logout() {
    this.token = null;
  }

  preRequest(request) {
    return this.token ? request.set('authorization', this.token) : request;
  }

  get(url) {
    const req = this.client.get(url);

    return this.preRequest(req);
  }

  post(url) {
    const req = this.client.post(url);

    return this.preRequest(req);
  }

  put(url) {
    const req = this.client.put(url);

    return this.preRequest(req);
  }

  patch(url) {
    const req = this.client.patch(url);

    return this.preRequest(req);
  }

  delete(url) {
    const req = this.client.delete(url);

    return this.preRequest(req);
  }
}

export default new App();

Test

// test/article.spec.js

import app from './testUtils/app';

describe('Articles', () => {
  describe('GET', () => {
    it('should not allow unauthenticated users to list all articles', async () => {
      const res = await app.get('/articles');

      expect(res.status).toBe(401);
    });

    it('should allow authenticated users to list all articles', async () => {
      await app.loginRandom();
      const { body } = await app.get('/articles');
      expect(body.articles).toEqual('All articles');
      app.logout();
    });
  });
});

Licence

MIT © Mutai Mwiti | GitHub | GitLab

DISCLAIMER: All opinions expressed in this repository are mine and do not reflect any company or organisation I'm involved with.