Book Image

Test-Driven Development with PHP 8

By : Rainier Sarabia
Book Image

Test-Driven Development with PHP 8

By: Rainier Sarabia

Overview of this book

PHP web developers end up building complex enterprise projects without prior experience in test-driven and behavior-driven development which results in software that’s complex and difficult to maintain. This step-by-step guide helps you manage the complexities of large-scale web applications. It takes you through the processes of working on a project, starting from understanding business requirements and translating them into actual maintainable software, to automated deployments. You’ll learn how to break down business requirements into workable and actionable lists using Jira. Using those organized lists of business requirements, you’ll understand how to implement behavior-driven development (BDD) and test-driven development (TDD) to start writing maintainable PHP code. You’ll explore how to use the automated tests to help you stop introducing regressions to an application each time you release code by using continuous integration. By the end of this book, you’ll have learned how to start a PHP project, break down the requirements, build test scenarios and automated tests, and write more testable and maintainable PHP code. By learning these processes, you’ll be able to develop more maintainable, and reliable enterprise PHP applications.
Table of Contents (17 chapters)
1
Part 1 – Technical Background and Setup
6
Part 2 – Implementing Test-Driven Development in a PHP Project
11
Part 3 – Deployment Automation and Monitoring

TDD with the Liskov Substitution Principle

The LSP was introduced by Barbara Liskov. The way that I use it is that an implementation of an interface should be replaceable with another implementation of that interface without changing the behavior. If you are extending a superclass, the child class must be able to substitute the superclass without breaking the behavior.

In this example, let’s try adding a business rule to reject toy car models that were built on or before 1950.

As usual, let’s start with a test:

  1. Open the YearValidatorTest.php class we created earlier and modify the test class with the following:

codebase/symfony/tests/Unit/Validator/YearValidatorTest.php

<?php
namespace App\Tests\Unit\Validator;
use App\Validator\ToyCarTooOldException;
use PHPUnit\Framework\TestCase;
use App\Validator\YearValidator;
class YearValidatorTest extends TestCase
{
    /**
     * @param $data
     * @param $expected
     * @dataProvider provideYear...