Add logic for removeUnneededExtensions

ampproject · Oct 1, 2021 · 1d2aefe · 1d2aefe
1 parent 7231700
commit 1d2aefe
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Showing 2 changed files with 68 additions and 6 deletions.
diff --git a/src/Optimizer/Transformer/AutoExtensions.php b/src/Optimizer/Transformer/AutoExtensions.php
@@ -53,6 +53,22 @@ final class AutoExtensions implements Transformer
      */
     private $spec;
 
+    /**
+     * List of extensions added by the maybeAddExtension method.
+     *
+     * @var array
+     */
+    private $addedExtensions = [];
+
+    /**
+     * List of extensions that should not be removed even when there is no usage in the HTML.
+     *
+     * @var array
+     */
+    private $protectedExtensions = [
+        'amp-carousel',
+    ];
+
     /**
      * Instantiate an AutoExtensions object.
      *
@@ -80,7 +96,7 @@ public function transform(Document $document, ErrorCollection $errors)
             $extensionScripts = $this->addMissingExtensions($document, $extensionScripts);
         }
 
-        $extensionScripts = $this->removeUnneededExtensions($document, $extensionScripts);
+        $extensionScripts = $this->removeUnneededExtensions($extensionScripts);
 
         $this->renderExtensionScripts($document, $extensionScripts);
     }
@@ -414,15 +430,19 @@ private function getTagAttributeList($tagName)
     /**
      * Remove unneeded extension scripts.
      *
-     * @param Document  $document         Document to scan for unneeded extensions.
      * @param Element[] $extensionScripts Array of extension scripts to check.
      * @return Element[] Adapted array of extension scripts.
      */
-    private function removeUnneededExtensions(Document $document, $extensionScripts)
+    private function removeUnneededExtensions($extensionScripts)
     {
-        // TODO: Add logic.
+        if (! $this->configuration->get(AutoExtensionsConfiguration::REMOVE_UNNEEDED_EXTENSIONS)) {
+            return $extensionScripts;
+        }
 
-        return $extensionScripts;
+        return array_filter($extensionScripts, function ($extension) {
+            return array_key_exists($extension, $this->addedExtensions)
+                || in_array($extension, $this->protectedExtensions);
+        }, ARRAY_FILTER_USE_KEY);
     }
 
     /**
@@ -521,6 +541,8 @@ private function maybeAddExtension(Document $document, $extensionScripts, $requi
             }
         }
 
+        $this->addedExtensions[$requiredExtension] = true;
+
         return $extensionScripts;
     }
 

diff --git a/tests/Optimizer/Transformer/AutoExtensionsTest.php b/tests/Optimizer/Transformer/AutoExtensionsTest.php
@@ -124,7 +124,47 @@ public function dataTransform()
                 . '        ad goes here'
                 . '    </section>'
                 . '</body></html>',
-            ]
+            ],
+
+            'keep unneeded amp-youtube extension when removeUnneededExtensions is false' => [
+                TestMarkup::DOCTYPE . '<html><head>' . TestMarkup::META_CHARSET
+                . '<script async custom-element="amp-youtube" src="https://cdn.ampproject.org/v0/amp-youtube-0.1.js"></script>'
+                . '<script async custom-element="amp-anim" src="https://cdn.ampproject.org/v0/amp-anim-0.1.js"></script>'
+                . '</head><body><amp-anim></amp-anim></body></html>',
+                TestMarkup::DOCTYPE . '<html><head>' . TestMarkup::META_CHARSET
+                . '<script async custom-element="amp-youtube" src="https://cdn.ampproject.org/v0/amp-youtube-0.1.js"></script>'
+                . '<script async custom-element="amp-anim" src="https://cdn.ampproject.org/v0/amp-anim-0.1.js"></script>'
+                . '</head><body><amp-anim></amp-anim></body></html>',
+            ],
+
+            'remove unneeded amp-youtube extension when removeUnneededExtensions is true' => [
+                TestMarkup::DOCTYPE . '<html><head>' . TestMarkup::META_CHARSET
+                . '<script async custom-element="amp-youtube" src="https://cdn.ampproject.org/v0/amp-youtube-0.1.js"></script>'
+                . '<script async custom-element="amp-anim" src="https://cdn.ampproject.org/v0/amp-anim-0.1.js"></script>'
+                . '</head><body><amp-anim></amp-anim></body></html>',
+                TestMarkup::DOCTYPE . '<html><head>' . TestMarkup::META_CHARSET
+                . '<script async custom-element="amp-anim" src="https://cdn.ampproject.org/v0/amp-anim-0.1.js"></script>'
+                . '</head><body><amp-anim></amp-anim></body></html>',
+                [],
+                [
+                    AutoExtensionsConfiguration::REMOVE_UNNEEDED_EXTENSIONS => true,
+                ]
+            ],
+
+            'keep unneeded amp-carousel extension when removeUnneededExtensions is true' => [
+                TestMarkup::DOCTYPE . '<html><head>' . TestMarkup::META_CHARSET
+                . '<script async src="https://cdn.ampproject.org/v0/amp-carousel-0.1.js" custom-element="amp-carousel"></script>'
+                . '<script async custom-element="amp-anim" src="https://cdn.ampproject.org/v0/amp-anim-0.1.js"></script>'
+                . '</head><body><amp-anim></amp-anim></body></html>',
+                TestMarkup::DOCTYPE . '<html><head>' . TestMarkup::META_CHARSET
+                . '<script async src="https://cdn.ampproject.org/v0/amp-carousel-0.1.js" custom-element="amp-carousel"></script>'
+                . '<script async custom-element="amp-anim" src="https://cdn.ampproject.org/v0/amp-anim-0.1.js"></script>'
+                . '</head><body><amp-anim></amp-anim></body></html>',
+                [],
+                [
+                    AutoExtensionsConfiguration::REMOVE_UNNEEDED_EXTENSIONS => true,
+                ]
+            ],
         ];
     }