return value of void functions used in several places

NULL return value prevents further asserts

In \PHPUnit\Framework\TestCase tests $this->assertTrue() method has no return value.
In PHP that means it returns NULL.
NULL in if conditions converted to FALSE.

In the following example inside the if the $this->assertSame() never gonna check that the $foo['bar'] is equal to '1.0' or not.

<?php
$foo = ['bar' => 'something'],
if ($this->assertTrue(isset($foo['bar']))) {
  $this->assertSame('1.0', $foo['bar']);
}
?>

1. \Drupal\KernelTests\Core\Asset\AttachedAssetsTest::testDynamicLibrary
2. \Drupal\Tests\content_translation\Functional\ContentTranslationUITestBase::doTestTranslationDeletion
3. \Drupal\Tests\views\Functional\Plugin\DisplayPageWebTest::assertPagePath
4. \Drupal\KernelTests\Core\Entity\EntityCrudHookTest::assertHookMessageOrder
5. \Drupal\Tests\views_ui\Functional\ExposedFormUITest::assertNoGroupedFilterErrors
6. \Drupal\KernelTests\Core\Database\FetchTest::testQueryFetchArray
7. \Drupal\KernelTests\Core\Database\FetchTest::testQueryFetchClass
8. \Drupal\KernelTests\Core\Database\FetchTest::testQueryFetchNum
9. \Drupal\KernelTests\Core\Database\FetchTest::testQueryFetchBoth
10. \Drupal\KernelTests\Core\Field\FieldItemTest::assertSavedFieldItemValue
11. \Drupal\Tests\image\Functional\ImageStyleDeleteTest::testDelete
12. \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest::assertTranslation
13. \update_manager_file_get

Actual return value of a function does not match to its @return PhpDoc

Bad

<?php
/**
 * @return bool
 */
function foo() {
  return myVoid();
}
?>

Good

<?php
function foo() {
  myVoid();
}
?>

If an $this->assert*() fails it throws an exception, it does not return TRUE or FALSE.

1. \Drupal\Tests\config_translation\Functional\ConfigTranslationUiTest::assertDisabledTextarea
2. \Drupal\Tests\system\Functional\Form\ConfirmFormTest::assertCancelLinkUrl
3. \Drupal\KernelTests\Core\Database\ConnectionUnitTest::assertConnection
4. \Drupal\KernelTests\Core\Database\ConnectionUnitTest::assertNoConnection
5. \Drupal\Tests\content_translation\Functional\ContentTranslationSettingsTest::assertSettings
6. \Drupal\Tests\views_ui\Functional\DefaultViewsTest::clickViewsOperationLink
7. \Drupal\KernelTests\Core\Plugin\Discovery\DiscoveryTestBase::assertDefinitionIdentical
8. \Drupal\Tests\editor\Functional\EditorUploadImageScaleTest::assertSavedMaxDimensions
9. \Drupal\Tests\field_ui\Kernel\EntityDisplayTest::assertDependencyHelper
10. \Drupal\KernelTests\Core\Entity\EntityQueryAggregateTest::assertResults
11. \Drupal\KernelTests\Core\Entity\EntityReferenceFieldTest::assertUserAutocreate
12. \Drupal\KernelTests\Core\Entity\EntityReferenceFieldTest::assertUserRoleAutocreate
13. \Drupal\Tests\system\Functional\System\ErrorHandlerTest::assertNoMessages
14. \Drupal\Tests\views\Functional\Plugin\ExposedFormTest::assertIds
15. \Drupal\Tests\views\Kernel\Handler\FieldKernelTest::assertSubString
16. \Drupal\Tests\views\Kernel\Handler\FieldKernelTest::assertNotSubString
17. \Drupal\Tests\system\Functional\Update\FieldSchemaDataUninstallUpdateTest::assertFieldSchemaData
18. \Drupal\KernelTests\Core\Entity\FieldTranslationSqlStorageTest::assertFieldStorageLangcode
19. \Drupal\Tests\views\Functional\Handler\FieldWebTest::assertSubString
20. \Drupal\Tests\views\Functional\Handler\FieldWebTest::assertNotSubString
21. \file_delete
22. \Drupal\Tests\filter\Kernel\FilterKernelTest::testLineBreakFilter
23. \Drupal\Tests\filter\Kernel\FilterKernelTest::assertFilteredString
24. \Drupal\Tests\filter\Kernel\FilterKernelTest::assertNormalized
25. \Drupal\Tests\filter\Kernel\FilterKernelTest::assertNoNormalized
26. \Drupal\Tests\views\Functional\Handler\HandlerTest::assertEqualValue
27. \Drupal\KernelTests\Core\File\HtaccessTest::assertFilePermissions
28. \Drupal\Tests\system\Functional\Mail\HtmlToTextTest::assertHtmlToText
29. \Drupal\Tests\system\Functional\Mail\HtmlToTextTest::testDrupalHtmlToTextBlockTagToNewline
30. \Drupal\Tests\image\Functional\ImageEffectsTest::assertImageEffect
31. \Drupal\KernelTests\KernelMissingDependentModuleMethodTest::publicCheckRequirements
32. \Drupal\KernelTests\KernelMissingDependentModuleTest::publicCheckRequirements
33. \Drupal\KernelTests\Core\Asset\LibraryDiscoveryIntegrationTest::assertAssetInLibrary
34. \Drupal\KernelTests\Core\Asset\LibraryDiscoveryIntegrationTest::assertNoAssetInLibrary
35. \locale_translation_batch_fetch_finished
36. \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest::assertNoConfigOverride
37. \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest::assertConfigOverride
38. \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest::assertActiveConfig
39. \Drupal\Tests\locale\Kernel\LocaleConfigSubscriberTest::assertNoTranslation
40. \Drupal\Tests\system\Functional\Menu\LocalTasksTest::assertLocalTaskAppers
41. \Drupal\Tests\image\Kernel\Migrate\d6\MigrateImageCacheTest::assertImageEffect
42. \Drupal\Tests\system\Functional\Module\ModuleTestBase::assertTableCount
43. \Drupal\Tests\system\Functional\Module\ModuleTestBase::assertModuleTablesExist
44. \Drupal\Tests\system\Functional\Module\ModuleTestBase::assertModuleConfig
45. \Drupal\Tests\system\Functional\Module\ModuleTestBase::assertNoModuleConfig
46. \Drupal\Tests\system\Functional\Batch\ProcessingTest::assertBatchMessages
47. \Drupal\Tests\views\Kernel\Entity\RowEntityRenderersTest::assertTranslations
48. \Drupal\Tests\views\Functional\SearchIntegrationTest::assertOneLink
49. \Drupal\Tests\system\Functional\Session\SessionHttpsTest::assertSessionIds
50. \Drupal\Tests\system\Functional\Session\SessionTest::testSessionSaveRegenerate
51. \Drupal\Tests\shortcut\Functional\ShortcutLinksTest::assertShortcutQuickLink
52. \Drupal\KernelTests\Core\Image\ToolkitGdTest::checkRequirements
53. \Drupal\KernelTests\Core\Database\TransactionTest::assertRowPresent
54. \Drupal\KernelTests\Core\Database\TransactionTest::assertRowAbsent
55. \Drupal\Tests\system\Functional\Path\UrlAlterFunctionalTest::assertUrlOutboundAlter
56. \Drupal\Tests\system\Functional\Path\UrlAlterFunctionalTest::assertUrlInboundAlter