Adoption and DocumentFragment

Tests for whatwg/dom#744.

The assumption here is an early return for DocumentFragment that has a host by adoptNode() and that adoption generally doesn't affect DocumentFragment otherwise (only its children).

custom-elements/adopted-callback.html

@@ -117,6 +117,38 @@
         });
     }, 'Moving the shadow host of a custom element from the owner document into ' + documentName + ' must enqueue and invoke adoptedCallback');
 
+    promise_test(function () {
+        return getDocument().then(function (doc) {
+            var instance = document.createElement('my-custom-element');
+            var host = document.createElement('div');
+            var shadowRoot = host.attachShadow({mode: 'closed'});
+            shadowRoot.appendChild(instance);
+            document.body.appendChild(host);
+
+            calls = [];
+            doc.documentElement.appendChild(shadowRoot);
+            assert_array_equals(calls, ['disconnected', 'adopted', document, doc, 'connected']);
+        });
+    }, 'Moving the shadow host\'s shadow of a custom element from the owner document into ' + documentName + ' must enqueue and invoke adoptedCallback');
+
+    promise_test(function () {
+        return getDocument().then(function (doc) {
+            var instance = document.createElement('my-custom-element');
+            var host = document.createElement('template');
+            var shadowRoot = host.content;
+            shadowRoot.appendChild(instance);
+            document.body.appendChild(host);
+
+            calls = [];
+            doc.documentElement.appendChild(shadowRoot);
+            if (documentName === "the document of the template elements") {
+                assert_array_equals(calls, ['connected']);
+            } else {
+                assert_array_equals(calls, ['adopted', shadowRoot.ownerDocument, doc, 'connected']);
+            }
+        });
+    }, 'Moving the <template>\'s content of a custom element from the owner document into ' + documentName + ' must enqueue and invoke adoptedCallback');
+
     promise_test(function () {
         return getDocument().then(function (doc) {
             var instance = document.createElement('my-custom-element');

dom/nodes/adoption.window.js

@@ -0,0 +1,58 @@
+// Testing DocumentFragment with host separately as it has a different node document by design
+test(() => {
+  const df = document.createElement("template").content;
+  const child = df.appendChild(new Text('hi'));
+  assert_not_equals(df.ownerDocument, document);
+  const nodeDocument = df.ownerDocument;
+  document.body.appendChild(df);
+  assert_equals(df.childNodes.length, 0);
+  assert_equals(child.ownerDocument, document);
+  assert_equals(df.ownerDocument, nodeDocument);
+}, `appendChild() and DocumentFragment with host`);
+
+test(() => {
+  const df = document.createElement("template").content;
+  const child = df.appendChild(new Text('hi'));
+  const nodeDocument = df.ownerDocument;
+  document.adoptNode(df);
+  assert_equals(df.childNodes.length, 1);
+  assert_equals(child.ownerDocument, nodeDocument);
+  assert_equals(df.ownerDocument, nodeDocument);
+}, `adoptNode() and DocumentFragment with host`);
+
+[
+  {
+    "name": "DocumentFragment",
+    "creator": doc => doc.createDocumentFragment()
+  },
+  {
+    "name": "ShadowRoot",
+    "creator": doc => doc.createElementNS("http://www.w3.org/1999/xhtml", "div").attachShadow({mode: "closed"})
+  }
+].forEach(dfTest => {
+  test(() => {
+    const doc = new Document();
+    const df = dfTest.creator(doc);
+    const child = df.appendChild(new Text('hi'));
+    assert_equals(df.ownerDocument, doc);
+
+    document.body.appendChild(df);
+    assert_equals(df.childNodes.length, 0);
+    assert_equals(child.ownerDocument, document);
+    assert_equals(df.ownerDocument, doc);
+  }, `appendChild() and ${dfTest.name}`);
+
+  test(() => {
+    const doc = new Document();
+    const df = dfTest.creator(doc);
+    const child = df.appendChild(new Text('hi'));
+    if (dfTest.name === "ShadowRoot") {
+      assert_throws("HierarchyRequestError", () => document.adoptNode(df));
+    } else {
+      document.adoptNode(df);
+      assert_equals(df.childNodes.length, 1);
+      assert_equals(child.ownerDocument, document);
+      assert_equals(df.ownerDocument, document);
+    }
+  }, `adoptNode() and ${dfTest.name}`);
+});