Issue #3230507: Create build tests for case where site is using core recommended Composer project

tests/src/Build/AttendedCoreRecommendedUpdateTest.php

@@ -20,16 +20,17 @@ class AttendedCoreRecommendedUpdateTest extends AttendedCoreUpdateTest {
   protected function prepareForUpdate(string $version): void {
     parent::prepareForUpdate($version);
 
-    $composer = $this->getWorkspaceDirectory() . "/composer.json";
-    $data = $this->readJson($composer);
-    $data['repositories']['drupal/core-recommended'] = [
-      'type' => 'path',
-      'url' => $this->createTargetMetapackage($version),
-      'options' => [
-        'symlink' => FALSE,
+    $this->alterPackage($this->getWorkspaceDirectory(), [
+      'repositories' => [
+        'drupal/core-recommended' => [
+          'type' => 'path',
+          'url' => $this->createTargetMetapackage($version),
+          'options' => [
+            'symlink' => FALSE,
+          ],
+        ],
       ],
-    ];
-    $this->writeJson($composer, $data);
+    ]);
   }
 
   /**
@@ -51,12 +52,12 @@ class AttendedCoreRecommendedUpdateTest extends AttendedCoreUpdateTest {
   protected function createTargetMetapackage(string $version): string {
     $destination = $this->mockPackage($this->getDrupalRoot() . '/composer/Metapackage/CoreRecommended');
 
-    $composer = $destination . '/composer.json';
-    $data = $this->readJson($composer);
-    $data['version'] = $version;
-    $data['require']['drupal/core'] = $version;
-    $this->writeJson($composer, $data);
-
+    $this->alterPackage($destination, [
+      'version' => $version,
+      'require' => [
+        'drupal/core' => $version,
+      ],
+    ]);
     return $destination;
   }