Issue #3321684: Should most validators that subscribe to PreCreate check readiness to update also subscribe to PreApply?

package_manager/tests/src/Kernel/ComposerExecutableValidatorTest.php

@@ -48,6 +48,31 @@ class ComposerExecutableValidatorTest extends PackageManagerKernelTestBase {
     $this->assertResultsWithHelp([$error], PreCreateEvent::class);
   }
 
+  /**
+   * Tests error on pre-apply if the Composer executable isn't found.
+   */
+  public function testErrorIfComposerNotFoundAfterStaged(): void {
+    TestComposerExecutableValidator::setCommandOutput("Composer version 2.2.12");
+    $exception = new IOException("This is your regularly scheduled error.");
+
+    $listener = function () use ($exception): void {
+      TestComposerExecutableValidator::setCommandOutput($exception);
+    };
+    $this->container->get('event_dispatcher')->addListener(PreApplyEvent::class, $listener, PHP_INT_MAX);
+
+    // The validator should translate that exception into an error.
+    $error = ValidationResult::createError([
+      $exception->getMessage(),
+    ]);
+    $stage = $this->assertResults([$error], PreApplyEvent::class);
+    $stage->destroy(TRUE);
+
+    TestComposerExecutableValidator::setCommandOutput("Composer version 2.2.12");
+    $this->enableModules(['help']);
+    $this->container->get('event_dispatcher')->addListener(PreApplyEvent::class, $listener, PHP_INT_MAX);
+    $this->assertResultsWithHelp([$error], PreApplyEvent::class, FALSE);
+  }
+
   /**
    * Data provider for testComposerVersionValidation().
    *
@@ -157,7 +182,7 @@ class ComposerExecutableValidatorTest extends PackageManagerKernelTestBase {
   }
 
   /**
-   * Tests validation of various Composer versions.
+   * Tests validation of various Composer versions on pre-apply.
    *
    * @param string $reported_version
    *   The version of Composer that `composer --version` should report.
@@ -168,24 +193,20 @@ class ComposerExecutableValidatorTest extends PackageManagerKernelTestBase {
    */
   public function testComposerVersionValidationAfterStaged(string $reported_version, array $expected_results): void {
     TestComposerExecutableValidator::setCommandOutput("Composer version 2.2.12");
-    $this->container->get('event_dispatcher')->addListener(
-      PreApplyEvent::class,
-      function () use ($reported_version): void {
-        TestComposerExecutableValidator::setCommandOutput("Composer version $reported_version");
-      },
-      // Execute this listener immediately after the tested validator, which
-      // uses priority 200. This ensures informative test failures.
-      // @see \Drupal\package_manager\Validator\EnvironmentSupportValidator::getSubscribedEvents()
-      199
-    );
+    $listener = function () use ($reported_version): void {
+      TestComposerExecutableValidator::setCommandOutput("Composer version $reported_version");
+    };
+    $this->container->get('event_dispatcher')->addListener(PreApplyEvent::class, $listener, PHP_INT_MAX);
 
     // If the validator can't find a recognized, supported version of Composer,
     // it should produce errors.
     $stage = $this->assertResults($expected_results, PreApplyEvent::class);
     $stage->destroy(TRUE);
 
+    TestComposerExecutableValidator::setCommandOutput("Composer version 2.2.12");
     $this->enableModules(['help']);
-    $this->assertResultsWithHelp($expected_results, PreApplyEvent::class);
+    $this->container->get('event_dispatcher')->addListener(PreApplyEvent::class, $listener, PHP_INT_MAX);
+    $this->assertResultsWithHelp($expected_results, PreApplyEvent::class, FALSE);
   }
 
   /**
@@ -196,8 +217,11 @@ class ComposerExecutableValidatorTest extends PackageManagerKernelTestBase {
    * @param string|null $event_class
    *   (optional) The class of the event which should return the results. Must
    *   be passed if $expected_results is not empty.
+   * @param bool $assert_status_check
+   *   (optional) Whether the status checks should be asserted. Defaults to
+   *   TRUE.
    */
-  private function assertResultsWithHelp(array $expected_results, string $event_class = NULL): void {
+  private function assertResultsWithHelp(array $expected_results, string $event_class = NULL, bool $assert_status_check = TRUE): void {
     $url = Url::fromRoute('help.page', ['name' => 'package_manager'])
       ->setOption('fragment', 'package-manager-faq-composer-not-found')
       ->toString();
@@ -211,7 +235,9 @@ class ComposerExecutableValidatorTest extends PackageManagerKernelTestBase {
       $messages = array_map($map, $result->getMessages());
       $expected_results[$index] = ValidationResult::createError($messages);
     }
-    $this->assertStatusCheckResults($expected_results);
+    if ($assert_status_check) {
+      $this->assertStatusCheckResults($expected_results);
+    }
     $this->assertResults($expected_results, $event_class);
   }