Using PSR-4 Autoloading for your Drupal 7 Test Cases

Posted on 4th February 2020

How to use the PSR-4 autoloading standard for Drupal 7 Simpletest test cases.

The Traditional Way

The typical way of including test cases in Drupal 7 is to add one or more classes within a .test file - e.g. opdavies.test. This would typically include all of the different test cases for that module, and would be placed in the root of the module’s directory alongside the .info and .module files.

In order to load the files, each file would need to be declared within the .info file for the module.

There is a convention that if you have multiple tests for your project, these can be split into different files and grouped within a tests directory.

; Load a test file at the root of the module
files[] = opdavies.test

; Load a test file from within a subdirectory
files[] = tests/foo.test
files[] = tests/bar.test

Using the xautoload Module

Whilst splitting tests into separate files makes things more organised, each file needs to be loaded separately. This can be made simpler by using the Xautoload module, which supports wildcards when declaring files.

files[] = tests/**/*.test

This would load all of the .test files within the tests directory.

Using PSR-4 Autoloading

Another option is to use PSR-4 (or PSR-0) autoloading.

This should be a lot more familiar to those who have worked with Drupal 8, Symfony etc, and means that each test case is in its own file which is cleaner, files have the .php extension which is more standard, and the name of the file matches the name of the test class for consistency.

To do this, create a src/Tests (PSR-4) or lib/Drupal/{module_name}/Tests (PSR-0) directory within your module, and then add or move your test cases there. Add the appropriate namespace for your module, and ensure that DrupalWebTestCase or DrupalUnitTestCase is also namespaced.

// src/Tests/Functional/OliverDaviesTest.php

namespace Drupal\opdavies\Tests\Functional;

class OliverDaviesTest extends \DrupalWebTestCase {
  // ...
}

This also supports subdirectories, so you can group classes within Functional and Unit directories if you like.

If you want to see an real-world example, see the Drupal 7 branch of the Override Node Options module.

Digging into the simpletest_test_get_all function

This is the code within simpletest.module that makes this work:

// simpletest_test_get_all()

// ...

$module_dir = DRUPAL_ROOT . '/' . dirname($filename);

// Search both the 'lib/Drupal/mymodule' directory (for PSR-0 classes)
// and the 'src' directory (for PSR-4 classes).
foreach (array(
  'lib/Drupal/' . $name,
  'src',
) as $subdir) {

  // Build directory in which the test files would reside.
  $tests_dir = $module_dir . '/' . $subdir . '/Tests';

  // Scan it for test files if it exists.
  if (is_dir($tests_dir)) {
    $files = file_scan_directory($tests_dir, '/.*\\.php/');
    if (!empty($files)) {
      foreach ($files as $file) {

        // Convert the file name into the namespaced class name.
        $replacements = array(
          '/' => '\\',
          $module_dir . '/' => '',
          'lib/' => '',
          'src/' => 'Drupal\\' . $name . '\\',
          '.php' => '',
        );
        $classes[] = strtr($file->uri, $replacements);
      }
    }
  }
}

It looks for a the tests directory (src/Tests or lib/Drupal/{module_name}/Tests) within the module, and then finds any .php files within it. It then converts the file name into the fully qualified (namespaced) class name and loads it automatically.

Running the Tests

You can still run the tests from within the Simpletest UI, or from the command line using run-tests.sh.

If you want to run a specific test case using the --class option, you will now need to include the fully qualified name.

php scripts/run-tests.sh --class Drupal\\opdavies\\Tests\\Functional\\OliverDaviesTest

About Me

Picture of Oliver

Oliver Davies is a Full Stack Web Developer and System Administrator based in the UK. He is a Senior Software Engineer and Technical Team Lead at Inviqa and a part-time freelancer specialising in Drupal, Symfony and Laravel development and Linux systems administration.