--- /dev/null
+<?php
+
+namespace Drupal\Tests\system\Functional\Module;
+
+use Drupal\Component\Utility\Unicode;
+
+/**
+ * Enable module without dependency enabled.
+ *
+ * @group Module
+ */
+class DependencyTest extends ModuleTestBase {
+ /**
+ * Checks functionality of project namespaces for dependencies.
+ */
+ public function testProjectNamespaceForDependencies() {
+ $edit = [
+ 'modules[filter][enable]' => TRUE,
+ ];
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+ // Enable module with project namespace to ensure nothing breaks.
+ $edit = [
+ 'modules[system_project_namespace_test][enable]' => TRUE,
+ ];
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+ $this->assertModules(['system_project_namespace_test'], TRUE);
+ }
+
+ /**
+ * Attempts to enable the Content Translation module without Language enabled.
+ */
+ public function testEnableWithoutDependency() {
+ // Attempt to enable Content Translation without Language enabled.
+ $edit = [];
+ $edit['modules[content_translation][enable]'] = 'content_translation';
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+ $this->assertText(t('Some required modules must be enabled'), 'Dependency required.');
+
+ $this->assertModules(['content_translation', 'language'], FALSE);
+
+ // Assert that the language tables weren't enabled.
+ $this->assertTableCount('language', FALSE);
+
+ $this->drupalPostForm(NULL, NULL, t('Continue'));
+ $this->assertText(t('2 modules have been enabled: Content Translation, Language.'), 'Modules status has been updated.');
+ $this->assertModules(['content_translation', 'language'], TRUE);
+
+ // Assert that the language YAML files were created.
+ $storage = $this->container->get('config.storage');
+ $this->assertTrue(count($storage->listAll('language.entity.')) > 0, 'Language config entity files exist.');
+ }
+
+ /**
+ * Attempts to enable a module with a missing dependency.
+ */
+ public function testMissingModules() {
+ // Test that the system_dependencies_test module is marked
+ // as missing a dependency.
+ $this->drupalGet('admin/modules');
+ $this->assertRaw(t('@module (<span class="admin-missing">missing</span>)', ['@module' => Unicode::ucfirst('_missing_dependency')]), 'A module with missing dependencies is marked as such.');
+ $checkbox = $this->xpath('//input[@type="checkbox" and @disabled="disabled" and @name="modules[system_dependencies_test][enable]"]');
+ $this->assert(count($checkbox) == 1, 'Checkbox for the module is disabled.');
+ }
+
+ /**
+ * Tests enabling a module that depends on an incompatible version of a module.
+ */
+ public function testIncompatibleModuleVersionDependency() {
+ // Test that the system_incompatible_module_version_dependencies_test is
+ // marked as having an incompatible dependency.
+ $this->drupalGet('admin/modules');
+ $this->assertRaw(t('@module (<span class="admin-missing">incompatible with</span> version @version)', [
+ '@module' => 'System incompatible module version test (>2.0)',
+ '@version' => '1.0',
+ ]), 'A module that depends on an incompatible version of a module is marked as such.');
+ $checkbox = $this->xpath('//input[@type="checkbox" and @disabled="disabled" and @name="modules[system_incompatible_module_version_dependencies_test][enable]"]');
+ $this->assert(count($checkbox) == 1, 'Checkbox for the module is disabled.');
+ }
+
+ /**
+ * Tests enabling a module that depends on a module with an incompatible core version.
+ */
+ public function testIncompatibleCoreVersionDependency() {
+ // Test that the system_incompatible_core_version_dependencies_test is
+ // marked as having an incompatible dependency.
+ $this->drupalGet('admin/modules');
+ $this->assertRaw(t('@module (<span class="admin-missing">incompatible with</span> this version of Drupal core)', [
+ '@module' => 'System incompatible core version test',
+ ]), 'A module that depends on a module with an incompatible core version is marked as such.');
+ $checkbox = $this->xpath('//input[@type="checkbox" and @disabled="disabled" and @name="modules[system_incompatible_core_version_dependencies_test][enable]"]');
+ $this->assert(count($checkbox) == 1, 'Checkbox for the module is disabled.');
+ }
+
+ /**
+ * Tests failing PHP version requirements.
+ */
+ public function testIncompatiblePhpVersionDependency() {
+ $this->drupalGet('admin/modules');
+ $this->assertRaw('This module requires PHP version 6502.* and is incompatible with PHP version ' . phpversion() . '.', 'User is informed when the PHP dependency requirement of a module is not met.');
+ $checkbox = $this->xpath('//input[@type="checkbox" and @disabled="disabled" and @name="modules[system_incompatible_php_version_test][enable]"]');
+ $this->assert(count($checkbox) == 1, 'Checkbox for the module is disabled.');
+ }
+
+ /**
+ * Tests enabling a module that depends on a module which fails hook_requirements().
+ */
+ public function testEnableRequirementsFailureDependency() {
+ \Drupal::service('module_installer')->install(['comment']);
+
+ $this->assertModules(['requirements1_test'], FALSE);
+ $this->assertModules(['requirements2_test'], FALSE);
+
+ // Attempt to install both modules at the same time.
+ $edit = [];
+ $edit['modules[requirements1_test][enable]'] = 'requirements1_test';
+ $edit['modules[requirements2_test][enable]'] = 'requirements2_test';
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+
+ // Makes sure the modules were NOT installed.
+ $this->assertText(t('Requirements 1 Test failed requirements'), 'Modules status has been updated.');
+ $this->assertModules(['requirements1_test'], FALSE);
+ $this->assertModules(['requirements2_test'], FALSE);
+
+ // Makes sure that already enabled modules the failing modules depend on
+ // were not disabled.
+ $this->assertModules(['comment'], TRUE);
+ }
+
+ /**
+ * Tests that module dependencies are enabled in the correct order in the UI.
+ *
+ * Dependencies should be enabled before their dependents.
+ */
+ public function testModuleEnableOrder() {
+ \Drupal::service('module_installer')->install(['module_test'], FALSE);
+ $this->resetAll();
+ $this->assertModules(['module_test'], TRUE);
+ \Drupal::state()->set('module_test.dependency', 'dependency');
+ // module_test creates a dependency chain:
+ // - color depends on config
+ // - config depends on help
+ $expected_order = ['help', 'config', 'color'];
+
+ // Enable the modules through the UI, verifying that the dependency chain
+ // is correct.
+ $edit = [];
+ $edit['modules[color][enable]'] = 'color';
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+ $this->assertModules(['color'], FALSE);
+ // Note that dependencies are sorted alphabetically in the confirmation
+ // message.
+ $this->assertText(t('You must enable the Configuration Manager, Help modules to install Color.'));
+
+ $edit['modules[config][enable]'] = 'config';
+ $edit['modules[help][enable]'] = 'help';
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+ $this->assertModules(['color', 'config', 'help'], TRUE);
+
+ // Check the actual order which is saved by module_test_modules_enabled().
+ $module_order = \Drupal::state()->get('module_test.install_order') ?: [];
+ $this->assertIdentical($module_order, $expected_order);
+ }
+
+ /**
+ * Tests attempting to uninstall a module that has installed dependents.
+ */
+ public function testUninstallDependents() {
+ // Enable the forum module.
+ $edit = ['modules[forum][enable]' => 'forum'];
+ $this->drupalPostForm('admin/modules', $edit, t('Install'));
+ $this->drupalPostForm(NULL, [], t('Continue'));
+ $this->assertModules(['forum'], TRUE);
+
+ // Check that the comment module cannot be uninstalled.
+ $this->drupalGet('admin/modules/uninstall');
+ $checkbox = $this->xpath('//input[@type="checkbox" and @name="uninstall[comment]" and @disabled="disabled"]');
+ $this->assert(count($checkbox) == 1, 'Checkbox for uninstalling the comment module is disabled.');
+
+ // Delete any forum terms.
+ $vid = $this->config('forum.settings')->get('vocabulary');
+ // Ensure taxonomy has been loaded into the test-runner after forum was
+ // enabled.
+ \Drupal::moduleHandler()->load('taxonomy');
+ $terms = entity_load_multiple_by_properties('taxonomy_term', ['vid' => $vid]);
+ foreach ($terms as $term) {
+ $term->delete();
+ }
+ // Uninstall the forum module, and check that taxonomy now can also be
+ // uninstalled.
+ $edit = ['uninstall[forum]' => 'forum'];
+ $this->drupalPostForm('admin/modules/uninstall', $edit, t('Uninstall'));
+ $this->drupalPostForm(NULL, NULL, t('Uninstall'));
+ $this->assertText(t('The selected modules have been uninstalled.'), 'Modules status has been updated.');
+
+ // Uninstall comment module.
+ $edit = ['uninstall[comment]' => 'comment'];
+ $this->drupalPostForm('admin/modules/uninstall', $edit, t('Uninstall'));
+ $this->drupalPostForm(NULL, NULL, t('Uninstall'));
+ $this->assertText(t('The selected modules have been uninstalled.'), 'Modules status has been updated.');
+ }
+
+}