From bb494666b8bf8c81d3fcf83a24ac847f956fd209 Mon Sep 17 00:00:00 2001
From: Dima Voytenko <dvoytenko@google.com>
Date: Wed, 3 Mar 2021 17:44:19 -0800
Subject: [PATCH] Explicitly specify the version of automatic legacy extensions
 (#33048)

* Explicitly specify the version of automatic legacy extensions

* fix tests
---
 src/custom-element.js                     |  6 ++--
 test/unit/test-custom-element-registry.js |  2 +-
 test/unit/test-custom-element.js          | 37 +++++++++++++++++++++++
 3 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/src/custom-element.js b/src/custom-element.js
index ba300c719ac6..a8f075a3f10a 100644
--- a/src/custom-element.js
+++ b/src/custom-element.js
@@ -964,11 +964,13 @@ function createBaseCustomElementClass(win) {
         const ampdoc = ampdocService.getAmpDoc(this);
         this.ampdoc_ = ampdoc;
         // Load the pre-stubbed extension if needed.
-        const extensionId = this.tagName.toLowerCase();
+        const extensionId = this.localName;
         if (!this.implClass_ && !ampdoc.declaresExtension(extensionId)) {
           Services.extensionsFor(win).installExtensionForDoc(
             ampdoc,
-            extensionId
+            extensionId,
+            // The legacy auto-extensions are always 0.1.
+            '0.1'
           );
         }
       }
diff --git a/test/unit/test-custom-element-registry.js b/test/unit/test-custom-element-registry.js
index 7d1856c211ca..c27495c3de67 100644
--- a/test/unit/test-custom-element-registry.js
+++ b/test/unit/test-custom-element-registry.js
@@ -153,7 +153,7 @@ describes.realWin('CustomElement register', {amp: true}, (env) => {
     const element = doc.createElement('amp-element2');
     doc.body.appendChild(element);
     expect(stub).to.be.calledOnce;
-    expect(stub).to.be.calledWithExactly(ampdoc, 'amp-element2');
+    expect(stub).to.be.calledWithExactly(ampdoc, 'amp-element2', '0.1');
   });
 
   it('should not install declared pre-stubbed element extension', () => {
diff --git a/test/unit/test-custom-element.js b/test/unit/test-custom-element.js
index 1d784a8df2d5..6d48b94c4e97 100644
--- a/test/unit/test-custom-element.js
+++ b/test/unit/test-custom-element.js
@@ -243,6 +243,43 @@ describes.realWin('CustomElement', {amp: true}, (env) => {
         // expect(build.calledOnce).to.equal(true);
       });
 
+      it('StubElement - should try to install an unregistered legacy extensions', () => {
+        const LegacyElementClass = createAmpElementForTesting(win, ElementStub);
+        win.customElements.define('amp-legacy', LegacyElementClass);
+        win.__AMP_EXTENDED_ELEMENTS['amp-legacy'] = ElementStub;
+
+        const extensions = Services.extensionsFor(win);
+        env.sandbox.stub(extensions, 'installExtensionForDoc');
+
+        const element = new LegacyElementClass();
+        env.sandbox.stub(element, 'buildInternal');
+
+        container.appendChild(element);
+        expect(element.readyState).to.equal('upgrading');
+        expect(extensions.installExtensionForDoc).to.be.calledOnce.calledWith(
+          ampdoc,
+          'amp-legacy',
+          '0.1'
+        );
+      });
+
+      it('StubElement - should not try to install a pre-registered legacy extensions', () => {
+        const LegacyElementClass = createAmpElementForTesting(win, ElementStub);
+        win.customElements.define('amp-legacy', LegacyElementClass);
+        win.__AMP_EXTENDED_ELEMENTS['amp-legacy'] = ElementStub;
+        ampdoc.declareExtension('amp-legacy');
+
+        const extensions = Services.extensionsFor(win);
+        env.sandbox.stub(extensions, 'installExtensionForDoc');
+
+        const element = new LegacyElementClass();
+        env.sandbox.stub(element, 'buildInternal');
+
+        container.appendChild(element);
+        expect(element.readyState).to.equal('upgrading');
+        expect(extensions.installExtensionForDoc).to.not.be.called;
+      });
+
       it('Element - should only add classes on first attachedCallback', () => {
         const element = new ElementClass();
         const buildPromise = Promise.resolve();