How to Setup Testing of Modules and Themes

The term extension will be used to refer to themes and modules interchangeably.

Unit Test Quick Start

1. Ensure your extension has composer.json in it's root directory.
2. Configure Drupal Test autoloading for your extension.
3. Namespace all tests with Drupal\Tests\{extension_name}\{suite type}
4. Place all tests relative to your extension's root directory in tests/src/{suite type}/, e.g. my_module/tests/src/Unit/MyModuleUnitTest.php
5. Suffix all test classes with {suite type}Test.php; not just Test.php.
6. Extend \AKlump\DrupalTest\*\UnitTestCase for your Unit test classes.

Test File Structure

Each module or theme provides tests and schema files relative to it's own directory (.). Following this convention allows the test runner to auto-discover these tests. e.g.,

.
└── tests
    ├── jsonschema
    │   └── story_resource.json
    └── src
        ├── Client
        │   ├── Service
        │   │   └── EarthriseServiceClientTest.php
        ├── Kernel
        │   ├── Service
        │   │   ├── BreakpointServiceKernelTest.php
        │   └── TransformKernelTest.php
        ├── TestBase.php
        └── Unit
            ├── Service
            │   └── EarthriseServiceUnitTest.php
            └── TransformUnitTest.php

Must Test Classes Test a Single Class?

Unit and Kernel tests do not have to test a single class, for example if you are writing a test to cover theme functions. In order to make this happen you have to do the following in your test class:

    class InTheLoftThemeKernelTest extends KernelTestCase {

      protected $schema = [

        // By setting this to false, we indicate we are not testing a class.
        'classToBeTested' => FALSE,
      ];

    ...