17 files declare their use of ContactForm

ConfigActionsTest.php in core/modules/contact/tests/src/Kernel/ConfigActionsTest.php
ConfigTranslationListUiTest.php in core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php
ContactFieldsTest.php in core/modules/contact/tests/src/Kernel/Views/ContactFieldsTest.php
ContactFormResourceTestBase.php in core/modules/contact/tests/src/Functional/Rest/ContactFormResourceTestBase.php
ContactFormTest.php in core/modules/jsonapi/tests/src/Functional/ContactFormTest.php
ContactFormValidationTest.php in core/modules/contact/tests/src/Kernel/ContactFormValidationTest.php
ContactSitewideTest.php in core/modules/contact/tests/src/Functional/ContactSitewideTest.php
ContentEntityNullStorageTest.php in core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNullStorageTest.php
demo_umami.profile in core/profiles/demo_umami/demo_umami.profile
Enables modules and site configuration for a demo_umami site installation.
InputTest.php in core/tests/Drupal/KernelTests/Core/Recipe/InputTest.php
MessageResourceTestBase.php in core/modules/contact/tests/src/Functional/Rest/MessageResourceTestBase.php
MessageTest.php in core/modules/jsonapi/tests/src/Functional/MessageTest.php
MigrateContactCategoryTest.php in core/modules/contact/tests/src/Kernel/Migrate/MigrateContactCategoryTest.php
RecipeCommandTest.php in core/tests/Drupal/FunctionalTests/Core/Recipe/RecipeCommandTest.php
standard.profile in core/profiles/standard/standard.profile
Enables modules and site configuration for a standard site installation.
StandardRecipeInstallTest.php in core/tests/Drupal/FunctionalTests/Core/Recipe/StandardRecipeInstallTest.php
StandardTestTrait.php in core/profiles/standard/tests/src/Traits/StandardTestTrait.php

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