Book Image

Building Enterprise JavaScript Applications

By : Daniel Li
Book Image

Building Enterprise JavaScript Applications

By: Daniel Li

Overview of this book

With the over-abundance of tools in the JavaScript ecosystem, it's easy to feel lost. Build tools, package managers, loaders, bundlers, linters, compilers, transpilers, typecheckers - how do you make sense of it all? In this book, we will build a simple API and React application from scratch. We begin by setting up our development environment using Git, yarn, Babel, and ESLint. Then, we will use Express, Elasticsearch and JSON Web Tokens (JWTs) to build a stateless API service. For the front-end, we will use React, Redux, and Webpack. A central theme in the book is maintaining code quality. As such, we will enforce a Test-Driven Development (TDD) process using Selenium, Cucumber, Mocha, Sinon, and Istanbul. As we progress through the book, the focus will shift towards automation and infrastructure. You will learn to work with Continuous Integration (CI) servers like Jenkins, deploying services inside Docker containers, and run them on Kubernetes. By following this book, you would gain the skills needed to build robust, production-ready applications.
Table of Contents (26 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Free Chapter
1
The Importance of Good Code
Index

Unit testing ValidationError


Next, let's focus on testing the ValidationError class. Once again, we will move the validation.js file into its own director:

$ cd src/validators/errors/ && \
  mkdir validation-error && \
  mv validation-error.js validation-error/index.js && \
  cd ../../../

Now, create a new file atsrc/validators/errors/validation-error/index.unit.test.js to house our unit tests:

import assert from 'assert';
import ValidationError from '.';

describe('ValidationError', function () {
  it('should be a subclass of Error', function () {
    const validationError = new ValidationError();
    assert.equal(validationError instanceof Error, true);
  });
  describe('constructor', function () {
    it('should make the constructor parameter accessible via the `message` property of the instance', function () {
      const TEST_ERROR = 'TEST_ERROR';
      const validationError = new ValidationError(TEST_ERROR);
      assert.equal(validationError.message, TEST_ERROR...