[amp-mathml] add unit tests (#32842)

extensions/amp-mathml/0.1/test/test-amp-mathml.js

@@ -0,0 +1,65 @@
+/**
+ * Copyright 2021 The AMP HTML Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import '../amp-mathml';
+
+describes.realWin(
+  'amp-mathml',
+  {
+    amp: {
+      extensions: ['amp-mathml'],
+      canonicalUrl: 'https://foo.bar/baz',
+    },
+  },
+  (env) => {
+    let win, doc;
+    const title = 'My MathML formula';
+
+    beforeEach(() => {
+      win = env.win;
+      doc = win.document;
+    });
+
+    async function getAmpMathml() {
+      const ampMathml = doc.createElement('amp-mathml');
+      ampMathml.setAttribute('layout', 'container');
+      ampMathml.setAttribute(
+        'data-formula',
+        '[x = {-b pm sqrt{b^2-4ac} over 2a}.]'
+      );
+      ampMathml.setAttribute('title', title);
+      doc.body.appendChild(ampMathml);
+      await ampMathml.buildInternal();
+      await ampMathml.layoutCallback();
+      return ampMathml;
+    }
+
+    it('renders iframe with title', async () => {
+      const ampMathml = await getAmpMathml();
+      const iframe = ampMathml.firstChild;
+      expect(iframe).to.not.be.null;
+      expect(iframe.title).to.equal(title);
+    });
+
+    it('removes iframe on unlayout', async () => {
+      const ampMathml = await getAmpMathml();
+      const iframe = ampMathml.firstChild;
+      expect(iframe).to.not.be.null;
+      ampMathml.unlayoutCallback();
+      expect(ampMathml.querySelector('iframe')).to.be.null;
+    });
+  }
+);