Phpunit Testing

PHPUnit Testing in WP Rig

WP Rig encourages a test-driven approach for core theme logic and components. The theme is pre-configured for both unit testing (testing isolated PHP logic) and integration testing (testing within the WordPress environment).

Test Structure

All tests live in the tests/phpunit/ directory:

• Unit/: Tests for isolated PHP functions and classes that do not require a database or WordPress load.
• Integration/: Tests that require WordPress functions or database access.

Running Tests

Use the following commands to execute your tests:

Run All Tests

composer test

Run Unit Tests Only

composer test:unit

Run Integration Tests Only

composer test:integration

Writing a Test Case

Basic Unit Test

Extend PHPUnit\Framework\TestCase and focus on input/output of pure logic.

namespace WP_Rig\WP_Rig\Tests\Unit\My_Feature;

use PHPUnit\Framework\TestCase;
use WP_Rig\WP_Rig\My_Feature\Component;

class ComponentTest extends TestCase {
    public function test_get_slug() {
        $component = new Component();
        $this->assertEquals( 'my-feature', $component->get_slug() );
    }
}

Basic Integration Test

Integration tests use the WordPress testing framework, which must be set up correctly in your local environment.

namespace WP_Rig\WP_Rig\Tests\Integration\My_Feature;

use WP_UnitTestCase;
use WP_Rig\WP_Rig\My_Feature\Component;

class ComponentIntegrationTest extends WP_UnitTestCase {
    public function test_initialize_hooks() {
        $component = new Component();
        $component->initialize();
        $this->assertTrue( has_action( 'init', [ $component, 'my_init_hook' ] ) );
    }
}

Best Practices for Agents

1. Write Unit Tests First: For most business logic, unit tests are faster and easier to maintain.
2. Mocking: Use PHPUnit's mocking capabilities or libraries like Brain Monkey to simulate WordPress functions in unit tests.
3. Reproducers: When fixing a bug, first write a test that fails due to that bug, then implement the fix to make it pass.
4. Test Components: Every new component added to inc/ should have at least a basic unit test verifying its slug and initialization.
5. Coverage: Focus on testing complex logic, data transformations, and edge cases (e.g., empty settings, invalid input).
6. Environment: Ensure that the WordPress testing library is correctly installed and configured before running integration tests.