TestCase::getMockClass() is deprecated in PHPUnit 9.6 and removed from PHPUnit 10

Look great, but you might have missed one occurence in \Drupal\Tests\Core\Entity\EntityFieldManagerTest::setUpEntityTypeDefinitions()?

Seems like a lot of this code isn't needed?

In fact it seems that in some of the tests setUpEntityTypeManager() doesn't need to be called at all!

Could do with slightly less PHPCS errors, but seems like a nice clean-up :)

- Reason why we're doing this is clearly stated in the IS.
- All issues were addressed.
- No remaining occurrences of TestCase::getMockClass() found after applying the patch.
- Green TestBot.
- Added Bonus: Code clean-up.

RTBC for me.

When I see seemingly unnecessary test coverage like this I always wonder "why is it that way"? For all these tests, that's #2337191-9: Split up EntityManager into many services. The getMockClass() usage as it stands was added in the original prototype in that issue, and it appears to have been copied to all those tests from the original one:

+++ b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
@@ -140,93 +151,63 @@ class EntityManagerTest extends UnitTestCase {
   protected function setUpEntityManager($definitions = array()) {
-    $class = $this->getMockClass('Drupal\Core\Entity\EntityInterface');
-    foreach ($definitions as $entity_type) {
-      $entity_type->expects($this->any())
-        ->method('getClass')
-        ->will($this->returnValue($class));
+    $class = $this->getMockClass(EntityInterface::class);
+    foreach ($definitions as $key => $entity_type) {
+      // \Drupal\Core\Entity\EntityTypeInterface::getLinkTemplates() is called
+      // by \Drupal\Core\Entity\EntityManager::processDefinition() so it must
+      // always be mocked.
+      $entity_type->getLinkTemplates()->willReturn([]);
+
+      // Give the entity type a legitimate class to return.
+      $entity_type->getClass()->willReturn($class);

I reviewed each instance and confirmed that EntityTypeManagerTest does actually use it for something other than testing getMockClass() itself, but that the others don't.

Committed to 10.1.x, and cherry-picked to 10.0.x and 9.5.x as mostly a dead test code cleanup. Thanks!