71 files declare their use of UserInterface

AlertsJsonFeedTest.php in core/modules/announcements_feed/tests/src/FunctionalJavascript/AlertsJsonFeedTest.php
BlockContentRevisionsTest.php in core/modules/block_content/tests/src/Functional/BlockContentRevisionsTest.php
comment.module in core/modules/comment/comment.module
Enables users to comment on published content.
CommentManager.php in core/modules/comment/src/CommentManager.php
ContactController.php in core/modules/contact/src/Controller/ContactController.php
ContactPageAccess.php in core/modules/contact/src/Access/ContactPageAccess.php
ContentTranslationMetadataWrapper.php in core/modules/content_translation/src/ContentTranslationMetadataWrapper.php
ContentTranslationMetadataWrapperInterface.php in core/modules/content_translation/src/ContentTranslationMetadataWrapperInterface.php
ContentTranslationWorkflowsTest.php in core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php
delay_cache_tags_invalidation.module in core/modules/system/tests/modules/delay_cache_tags_invalidation/delay_cache_tags_invalidation.module
EntityApiTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityApiTest.php
EntityArgumentTest.php in core/modules/views/tests/src/Functional/Plugin/EntityArgumentTest.php
EntityReferenceFieldTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceFieldTest.php
EntityTest.php in core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
FileFieldWidgetTest.php in core/modules/file/tests/src/Functional/FileFieldWidgetTest.php
FilterEntityReferenceTest.php in core/modules/views/tests/src/Kernel/Handler/FilterEntityReferenceTest.php
HistoryHooks.php in core/modules/history/src/Hook/HistoryHooks.php
LayoutBuilderOverridesEditingThemeTest.php in core/modules/layout_builder/tests/src/Functional/LayoutBuilderOverridesEditingThemeTest.php
LinksetControllerTestBase.php in core/modules/system/tests/src/Functional/Menu/LinksetControllerTestBase.php
MigrateUserConfigsTest.php in core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserConfigsTest.php
MigrateUserSettingsTest.php in core/modules/user/tests/src/Kernel/Migrate/d7/MigrateUserSettingsTest.php
MigrateUserTest.php in core/modules/user/tests/src/Kernel/Migrate/d7/MigrateUserTest.php
MinimalTest.php in core/profiles/minimal/tests/src/Functional/MinimalTest.php
NavigationBlockUiTest.php in core/modules/navigation/tests/src/FunctionalJavascript/NavigationBlockUiTest.php
NodeAccessJoinTest.php in core/modules/node/tests/src/Functional/NodeAccessJoinTest.php
NodeDisplayConfigurableTest.php in core/modules/node/tests/src/Functional/NodeDisplayConfigurableTest.php
NodeFieldOverridesTest.php in core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
NodeHooks.php in core/modules/node/src/Hook/NodeHooks.php
NonStableModulesTest.php in core/modules/system/tests/src/Functional/Module/NonStableModulesTest.php
olivero.theme in core/themes/olivero/olivero.theme
Functions to support theming in the Olivero theme.
RegionalSettingsFormTest.php in core/modules/system/tests/src/Functional/Form/RegionalSettingsFormTest.php
RegisterAccessCheck.php in core/modules/user/src/Access/RegisterAccessCheck.php
ResourceObject.php in core/modules/jsonapi/src/JsonApiResource/ResourceObject.php
ResourceTestBase.php in core/modules/jsonapi/tests/src/Functional/ResourceTestBase.php
RevisionableContentEntityBaseTest.php in core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
RevisionLogEntityTrait.php in core/lib/Drupal/Core/Entity/RevisionLogEntityTrait.php
RevisionLogInterface.php in core/lib/Drupal/Core/Entity/RevisionLogInterface.php
session_test.module in core/modules/system/tests/modules/session_test/session_test.module
ShortcutCacheTagsTest.php in core/modules/shortcut/tests/src/Functional/ShortcutCacheTagsTest.php
SiteConfigureForm.php in core/lib/Drupal/Core/Installer/Form/SiteConfigureForm.php
StandardPerformanceTest.php in core/profiles/standard/tests/src/FunctionalJavascript/StandardPerformanceTest.php
SwitchShortcutSet.php in core/modules/shortcut/src/Form/SwitchShortcutSet.php
TestContent.php in core/modules/system/tests/modules/router_test_directory/src/TestContent.php
TestContextAwareBlock.php in core/modules/block/tests/modules/block_test/src/Plugin/Block/TestContextAwareBlock.php
TestControllers.php in core/modules/system/tests/modules/router_test_directory/src/TestControllers.php
TrackerController.php in core/modules/tracker/src/Controller/TrackerController.php
user.api.php in core/modules/user/user.api.php
Hooks provided by the User module.
user.module in core/modules/user/user.module
Enables the user registration and login system.
User.php in core/modules/user/src/Plugin/views/argument_default/User.php
User.php in core/modules/user/src/Entity/User.php
UserAccountFormFieldsTest.php in core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
UserAdminTest.php in core/modules/user/tests/src/Functional/UserAdminTest.php
UserAuthenticationController.php in core/modules/user/src/Controller/UserAuthenticationController.php
UserBulkForm.php in core/modules/user/src/Plugin/views/field/UserBulkForm.php
UserController.php in core/modules/user/src/Controller/UserController.php
UserEditedOwnAccountTest.php in core/modules/user/tests/src/Functional/UserEditedOwnAccountTest.php
UserLoginBlock.php in core/modules/user/src/Plugin/Block/UserLoginBlock.php
UserLoginForm.php in core/modules/user/src/Form/UserLoginForm.php
UserLoginTest.php in core/modules/user/tests/src/Functional/UserLoginTest.php
UserMailRequiredValidatorTest.php in core/modules/user/tests/src/Unit/Plugin/Validation/Constraint/UserMailRequiredValidatorTest.php
UserNameConstraintValidator.php in core/modules/user/src/Plugin/Validation/Constraint/UserNameConstraintValidator.php
UserNameValidatorTest.php in core/modules/user/tests/src/Kernel/UserNameValidatorTest.php
UserPasswordForm.php in core/modules/user/src/Form/UserPasswordForm.php
UserPasswordResetTest.php in core/modules/user/tests/src/Functional/UserPasswordResetTest.php
UserRegistrationResource.php in core/modules/user/src/Plugin/rest/resource/UserRegistrationResource.php
UserRegistrationResourceTest.php in core/modules/user/tests/src/Unit/UserRegistrationResourceTest.php
UserRegistrationRestTest.php in core/modules/user/tests/src/Functional/UserRegistrationRestTest.php
UserRegistrationTest.php in core/modules/user/tests/src/Functional/UserRegistrationTest.php
UserTest.php in core/modules/jsonapi/tests/src/Functional/UserTest.php
UserValidationTest.php in core/modules/user/tests/src/Kernel/UserValidationTest.php
WorkspaceListBuilder.php in core/modules/workspaces/src/WorkspaceListBuilder.php

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.