Custom Elements: layout tests for observedAttributes

third_party/WebKit/LayoutTests/custom-elements/spec/define-element.html

Index: third_party/WebKit/LayoutTests/custom-elements/spec/define-element.html
diff --git a/third_party/WebKit/LayoutTests/custom-elements/spec/define-element.html b/third_party/WebKit/LayoutTests/custom-elements/spec/define-element.html
index ca3c310d29f87fd57cb8ce96fa2cb44683df5cdc..68f7995b84c5c014434ed0b5dfcae14d0627f7f5 100644
--- a/third_party/WebKit/LayoutTests/custom-elements/spec/define-element.html
+++ b/third_party/WebKit/LayoutTests/custom-elements/spec/define-element.html
@@ -350,6 +350,32 @@ test_with_window((w) => {
 //        to the result of converting observedAttributesIterable to a sequence<DOMString>.
 //        Rethrow any exceptions.
 test_with_window((w) => {
+  let invocations = [];
+  let element = w.document.createElement('a-a');
+  element.setAttribute('a', '1');
+  element.setAttribute('b', '2');
+  let constructor = function () {};
+  constructor.prototype.attributeChangedCallback = function () { 
+    invocations.push(arguments[0]); 
+  };
+  constructor.observedAttributes = {[Symbol.iterator]:
+    function* () { yield 'a'; }
+  };
+  w.customElements.define('a-a', constructor);
+  w.document.body.appendChild(element);
+  assert_array_equals(invocations, ['a'], 'attributeChangedCllback should be invoked once for "a"'); 
+}, 'ObservedAttributes');

[dominicc (has gone to gerrit), 2016/09/12 05:31:44]

Could you write prose here? Like observed attributes are retrieved from
iterators or something like that?

It might be worth having two or three attributes, too, instead of just one.

+
+test_with_window((w) => {
+  let constructor = function () {};
+  constructor.prototype.attributeChangedCallback = function () { };
+  constructor.observedAttributes = {[Symbol.iterator]: 1};
+  assert_throws(TypeError.prototype, () => {
+    w.customElements.define('a-a', constructor);
+  }, 'converting value that is not an object should throw TypeError');
+}, 'Converting observedAttributes to sequence<DOMString>, not an object');

[dominicc (has gone to gerrit), 2016/09/12 05:31:44]

Maybe write

... non-object observedAttributes ...

and remove , not an object.

What you have is a tiny bit confusing, it sounds a bit like you're *not
converting observedAttributes to an object, but to a sequence<DOMString>.* That
is true, but not what's interesting about this test.

+
+test_with_window((w) => {
   class X extends w.HTMLElement{
     constructor() { super(); }
     attributeChangedCallback() {}
@@ -357,9 +383,17 @@ test_with_window((w) => {
   }
   assert_throws(TypeError.prototype, () => {
     w.customElements.define('a-a', X);
-  }, 'converting RegExp to sequence<DOMString> should throw TypeError');
-}, 'exception thrown while converting observedAttributes to ' +
-   'sequence<DOMString> should be rethrown');
+  }, 'converting RegExp should throw TypeError');
+}, 'Converting observedAttributes to sequence<DOMString>, regular expression');
+
+test_with_window((w) => {
+  let constructor = function () {};
+  constructor.prototype.attributeChangedCallback = function () { };
+  constructor.observedAttributes = {};
+  assert_throws(TypeError.prototype, () => {
+    w.customElements.define('a-a', constructor);
+  }, 'If iterator method is undefined, it should throw TypeError');
+}, 'Converting observedAttributes to sequence<DOMString>, iterator method not defined');
 
 // 14.9.2 test Get(constructor, observedAttributes) does not throw if
 // attributeChangedCallback is undefined.