Introduction to PHPUnit
PHPUnit is a popular helpful testing framework or tool for PHP program source code. PHPUnit is used to create and run automated source code unit tests in a specific order. It allows PHP web developers to test and analyse multiple individual units of source code, such as program functions and methods, to ensure that all testing processes are running correctly and in the proper order, as required. Automated testing in PHPUnit helps web developers catch bugs in source code immediately, improve the quality of existing program source code, and provide timely upgrades and maintenance.
Why Use PHPUnit?
- Automated Testing – PHPUnit features allow web developers to automate the testing process of their existing program source code, saving system processing time and reducing human error.
- Test-Driven Development (TDD) – Using PHPUnit, developers can follow the TDD process, where users write tests for real-time program source code before creating it. This process ensures that user program source code is thoroughly tested during development.
- Regression Testing – After users write tests for their PHPUnit program source code, running PHPUnit in a regular sequence ensures that new PHPUnit user modifications do not impact previously functioning capabilities.
- Refactoring – PHPUnit helps developers ensure that existing capabilities are maintained even when they refactor or reorganize their program source code.
Key Features of the PHPUnit Framework.
- Assertions – PHPUnit’s various assertions are methods that test program conditions in the program source code you create to verify that expected values properly match real-time values.
- Test Suite – A collection of related tests in PHPUnit that developers can run simultaneously.
- Mock Objects – PHPUnit allows users to use mock objects to observe complex dependencies, making it easier to test isolated units of program source code.
- Code Coverage – It can prepare a detailed report of PHPUnit source code coverage, giving you a preview of which lines of program source code are being tested and which are not.
Setting up PHPUnit/Installing PHPUnit.
Developers can install PHPUnit via Composer, which is the recommended method; it automatically checks compatibility with your PHP version.
Step 1 – First, install PHPUnit globally on your system using Composer.
composer global require phpunit/phpunit
Users can install PHPUnit by adding it as a development dependency to a specific project, in an alternative order.
composer require –dev phpunit/phpunit
Step 2 – Here, users must first ensure that Composer’s bin directory is in their system’s $PATH so that they can use PHPUnit from the command line. This allows them to check whether PHPUnit is installed in the proper order on their machine.
phpunit –version
Configuring PHPUnit on the system.
To configure PHPUnit on their system, users can create a phpunit.xml configuration file in the root of their project. This file allows users to specify testing directories, testing options, and other configuration details.
Example of phpunit.xml.
<?xml version=”1.0″ encoding=”UTF-8″?>
<phpunit bootstrap=”vendor/autoload.php”>
<testsuites>
<testsuite name=”TestProject Test Suite”>
<directory suffix=”Test.php”>./tests</directory>
</testsuite>
</testsuites>
</phpunit>
- bootstrap – This indicates a bootstrap file to add before running PHPUnit tests, typically Composer’s autoloader.
- testsuites – This defines a set of tests to run in PHPUnit, typically pointing to a directory containing test classes.
Writing your first PHPUnit test.
A PHPUnit test typically involves testing a small, separate portion of a user application, such as a method in a program source class. PHPUnit provides several assertion methods for testing the user’s results.
Example class to test in PHPUnit.
So, let’s create a basic class that we want to test. For example, a Calculate class is created.
// src/Calculat.php
namespace App;
class Calculat
{
public function addition($p, $q)
{
return $p + $q;
}
public function subtract($p, $q)
{
return $p – $q;
}
}
Writing a test case in PHPUnit.
Here, let’s create a test case for the Calculate class. The test class in PHPUnit should extend PHPUnit\Framework\TestCase.
///tests/CalculatTest.php
namespace Tests;
use PHPUnit\Framework\TestCase;
use App\Calculat;
class CalculatTest extends TestCase
{
private $calculat;
protected function setUp(): void
{
$this->calculat = new Calculat();
}
public function testAddition()
{
$output = $this->calculat->addition(3, 4);
$this->assertEquals(7, $output); // Asserts that 3 + 4 equals 7
}
public function testSubtract()
{
$output = $this->calculat->subtract(7, 3);
$this->assertEquals(4, $output); // Asserts that 7 – 3 equals 4
}
}
Here in this example.
- setUp() – This is a PHPUnit method that runs before every test. It is used to initialize resources or objects required in multiple tests.
- testAddition() and testSubtract() – These are multiple individual testing methods in the system, each testing a Behavior of the Calculate class.
- assertEquals() – This is an Assert class method that tests whether the expected value matches the real-time value returned by the method under test.
Running PHPUnit Tests.
To run their PHPUnit testing, users can execute the following command in their terminal.
phpunit –configuration phpunit.xml
If your PHPUnit testing here passes, PHPUnit will preview output like this:
Okay, 2 tests, 2 assertions.
If the PHPUnit testing here fails, it will show the user detailed information about what went wrong.
Common Assertions in PHPUnit.
PHPUnit provides multiple types of assertions for testing user source code. Here are some of the most commonly used assertions.
- assertEquals($expected, $actual) – This assertion indicates in PHPUnit that two values are equal.
- assertTrue($condition) – Indicates that a given condition is true in PHPUnit.
- assertFalse($condition) – Indicates that a given condition is false in PHPUnit.
- assertNull($value) – Indicates that a value is null in PHPUnit.
- assertNotNull($value) – Indicates that a value is not null in PHPUnit.
- assertCount($expectedCount, $array) – Indicates that an array has the expected number of elements.
- assertInstanceOf($expectedClass, $object) – Indicates that an object is an instance of a given class in PHPUnit.
Test-Driven Development (TDD) with PHPUnit.
PHPUnit is commonly used in Testing Driven Development (TDD), a popular software development methodology where users write tests before creating real-time program source code.
- Write a test – In this, you start by writing a failing test that explains the user’s desired behaviour.
- Write code – In this, you write enough source code to pass the PHPUnit testing.
- Refactor – In this, the user cleans up the program source code while ensuring that the PHPUnit testing still passes.
Mocking and Stubbing.
In some particular situations, users may need to test program source code that depends on other classes or external services. Mocks and stubs are used to monitor these dependencies separately.
- Mocks – These are objects that mimic the behaviour of real-time objects and allow the user to define how they should behave during PHPUnit testing.
- Stubs – These are simplified versions of objects in PHPUnit that return fixed data during testing.
Example of PHPUnit mocking.
use PHPUnit\Framework\TestCase;
class SomeClassTest extends TestCase
{
public function testDoSomething()
{
$mock = $this->createMock(otherClass::class);
$mock->method(‘testMethod’)->willReturn(32);
$output = $mock->testMethod();
$this->assertEquals(32, $output);
}
}
In this condition, otherClass is mocked, and its testMethod() is designed to return a fixed value (32) for testing.
Program source code coverage with PHPUnit.
In this case, PHPUnit can create a code coverage report that previews which lines of source code have been executed by PHPUnit’s testing, and which lines have not yet been covered. This helps users identify parts of the source code that have not yet been adequately tested.
To enable source code coverage in PHPUnit, users must install the Xdebug or PCOV tools and then run the testing with the following program command.
phpunit –coverage-html ./coverage-report
This generates an HTML report for you, giving you a preview of which parts of your program’s source code were covered by the testing process.
Key benefits of using PHPUnit
- Automated Testing – In PHPUnit, users write tests that can be executed in an automated order.
- Asertions – This allows users to check whether your program source code is performing the expected task.
- Mocking – This allows PHPUnit to follow complex dependencies for isolated testing.
- Code Coverage – This allows users to track which parts of your program source code have been thoroughly tested.
Conclusion on PHPUnit Testing.
PHPUnit is a powerful and useful tool for creating and running automated tests in PHP. It helps users improve the quality of their program source code, ensure consistent refactoring, and ensure that user source code performs the expected task. Here, by using PHPUnit, users can immediately catch errors and bugs in program code, improve the reliability of their existing applications, and make the developer development process more efficient.
