Add post about PSR-4 autoloading for Drupal 7 tests

source/_posts/psr4-autoloading-test-cases-drupal-7.md

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+---
+title: Using PSR-4 Autoloading for your Drupal 7 Test Cases
+excerpt: How to use the PSR-4 autoloading standard for Drupal 7 Simpletest test cases.
+tags: [drupal, drupal-planet, drupal-7, testing, simpletest, php, psr]
+date: 2020-02-04
+---
+<p>{{ page.excerpt }}</p>
+
+## 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.
+
+```ini
+; 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.
+
+[Xautoload module]: https://www.drupal.org/project/xautoload
+
+```ini
+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.
+
+```php
+// 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][override_node_options].
+
+[override_node_options]: https://git.drupalcode.org/project/override_node_options/tree/7.x-1.x
+
+### Digging into the simpletest_test_get_all function
+
+This is the code within `simpletest.module` that makes this work:
+
+```php
+// 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
+```