1 files changed, 128 insertions, 0 deletions
diff --git a/dom/tests/mochitest/webcomponents/upgrade_tests.js b/dom/tests/mochitest/webcomponents/upgrade_tests.js
new file mode 100644
index 0000000000..85cff984f0
--- /dev/null
+++ b/dom/tests/mochitest/webcomponents/upgrade_tests.js
@@ -0,0 +1,128 @@
+function test_upgrade(f, msg) {
+  // Run upgrading test on an element created by HTML parser.
+  test_with_new_window(function (testWindow, testMsg) {
+    let elementParser = testWindow.document.querySelector("unresolved-element");
+    f(testWindow, elementParser, testMsg);
+  }, msg + " (HTML parser)");
+
+  // Run upgrading test on an element created by document.createElement.
+  test_with_new_window(function (testWindow, testMsg) {
+    let element = testWindow.document.createElement("unresolved-element");
+    testWindow.document.documentElement.appendChild(element);
+    f(testWindow, element, testMsg);
+  }, msg + " (document.createElement)");
+}
+
+// Test cases
+
+test_upgrade(function (testWindow, testElement, msg) {
+  class MyCustomElement extends testWindow.HTMLElement {}
+  testWindow.customElements.define("unresolved-element", MyCustomElement);
+  SimpleTest.is(
+    Object.getPrototypeOf(Cu.waiveXrays(testElement)),
+    MyCustomElement.prototype,
+    msg
+  );
+}, "Custom element must be upgraded if there is a matching definition");
+
+test_upgrade(function (testWindow, testElement, msg) {
+  testElement.remove();
+  class MyCustomElement extends testWindow.HTMLElement {}
+  testWindow.customElements.define("unresolved-element", MyCustomElement);
+  SimpleTest.is(
+    Object.getPrototypeOf(testElement),
+    testWindow.HTMLElement.prototype,
+    msg
+  );
+}, "Custom element must not be upgraded if it has been removed from tree");
+
+test_upgrade(function (testWindow, testElement, msg) {
+  let exceptionToThrow = { name: "exception thrown by a custom constructor" };
+  class ThrowCustomElement extends testWindow.HTMLElement {
+    constructor() {
+      super();
+      if (exceptionToThrow) {
+        throw exceptionToThrow;
+      }
+    }
+  }
+
+  let uncaughtError;
+  window.onerror = function (message, url, lineNumber, columnNumber, error) {
+    uncaughtError = error;
+    return true;
+  };
+  testWindow.customElements.define("unresolved-element", ThrowCustomElement);
+
+  SimpleTest.is(uncaughtError.name, exceptionToThrow.name, msg);
+}, "Upgrading must report an exception thrown by a custom element constructor");
+
+test_upgrade(function (testWindow, testElement, msg) {
+  class InstantiatesItselfAfterSuper extends testWindow.HTMLElement {
+    constructor(doNotCreateItself) {
+      super();
+      if (!doNotCreateItself) {
+        new InstantiatesItselfAfterSuper(true);
+      }
+    }
+  }
+
+  let uncaughtError;
+  window.onerror = function (message, url, lineNumber, columnNumber, error) {
+    uncaughtError = error;
+    return true;
+  };
+  testWindow.customElements.define(
+    "unresolved-element",
+    InstantiatesItselfAfterSuper
+  );
+
+  SimpleTest.is(uncaughtError.name, "TypeError", msg);
+}, "Upgrading must report an TypeError when the top of the " +
+  "construction stack is marked AlreadyConstructed");
+
+test_upgrade(function (testWindow, testElement, msg) {
+  class InstantiatesItselfBeforeSuper extends testWindow.HTMLElement {
+    constructor(doNotCreateItself) {
+      if (!doNotCreateItself) {
+        new InstantiatesItselfBeforeSuper(true);
+      }
+      super();
+    }
+  }
+
+  let uncaughtError;
+  window.onerror = function (message, url, lineNumber, columnNumber, error) {
+    uncaughtError = error;
+    return true;
+  };
+  testWindow.customElements.define(
+    "unresolved-element",
+    InstantiatesItselfBeforeSuper
+  );
+
+  SimpleTest.is(uncaughtError.name, "TypeError", msg);
+}, "Upgrading must report an TypeError when the top of the " +
+  "construction stack is marked AlreadyConstructed due to a custom element " +
+  "constructor constructing itself before super() call");
+
+test_upgrade(function (testWindow, testElement, msg) {
+  class MyOtherElement extends testWindow.HTMLElement {
+    constructor() {
+      super();
+      if (this == testElement) {
+        return testWindow.document.createElement("other-element");
+      }
+    }
+  }
+
+  let uncaughtError;
+  window.onerror = function (message, url, lineNumber, columnNumber, error) {
+    uncaughtError = error;
+    return true;
+  };
+  testWindow.customElements.define("unresolved-element", MyOtherElement);
+
+  SimpleTest.is(uncaughtError.name, "TypeError", msg);
+}, "Upgrading must report an TypeError when the returned element is " +
+  "not SameValue as the upgraded element");