Issue #3344127: Composer validate all fixture manipulation changes

package_manager/tests/modules/fixture_manipulator/src/FixtureManipulator.php

@@ -6,6 +6,7 @@ use Composer\Semver\VersionParser;
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Serialization\Yaml;
 use Symfony\Component\Filesystem\Filesystem;
+use Symfony\Component\Process\Process;
 
 /**
  * It manipulates.
@@ -40,6 +41,28 @@ class FixtureManipulator {
    */
   private string $dir;
 
+  /**
+   * Validate the fixtures still passes `composer validate`.
+   */
+  private function validateComposer(): void {
+    $process = new Process([
+      'composer',
+      'validate',
+      // @todo Check the lock file in https://drupal.org/i/3343827.
+      '--no-check-lock',
+      // @todo Just adding this to check if this makes many more tests pass. If
+      //   it does we might want to commit this issue with this flag that have
+      //   some level of validation and create a follow-up to fix the rest.
+      '--no-check-all',
+      '--no-check-publish',
+      '--with-dependencies',
+      '--no-interaction',
+      '--ansi',
+      '--no-cache',
+    ], $this->dir);
+    $process->mustRun();
+  }
+
   /**
    * Adds a package.
    *
@@ -357,7 +380,7 @@ class FixtureManipulator {
    * @param string $dir
    *   The directory to commit the changes to.
    */
-  protected function doCommitChanges(string $dir): void {
+  final protected function doCommitChanges(string $dir): void {
     if ($this->committed) {
       throw new \BadMethodCallException('Already committed.');
     }
@@ -372,6 +395,7 @@ class FixtureManipulator {
     }
     $this->committed = TRUE;
     $this->committingChanges = FALSE;
+    $this->validateComposer();
   }
 
   /**