CSS Motion Path: Web Platform tests for longhand parsing

third_party/WebKit/LayoutTests/external/wpt/css/motion-1/parsing/resources/parsing-testcommon.js

+'use strict';
+
+function assert_valid_value(property, value, serializedValue) {
+    if (arguments.length < 3)
+        serializedValue = value;
+
+    var stringifiedValue = JSON.stringify(value);
+
+    test(function(){
+        var div = document.createElement('div');
+        div.style[property] = value;
+        assert_not_equals(div.style[property], "");
+    }, "e.style['" + property + "'] = " + stringifiedValue + " should set the value");

[suzyh_UTC10 (ex-contributor), 2017/05/25 01:55:38]

I believe you modified this description in the version in
https://codereview.chromium.org/2882153004 to say "set the property value".
Likewise under assert_invalid_value below. I recommend diffing against that
submitted version in case there are any other discrepancies we've missed, just
for consistency.

[Eric Willigers, 2017/05/25 11:43:12]

Done.

+
+    test(function(){
+        var div = document.createElement('div');
+        div.style[property] = value;
+        var readValue = div.style[property];
+        assert_equals(readValue, serializedValue);
+        div.style[property] = readValue;
+        assert_equals(div.style[property], readValue);
+    }, "Serialization should round-trip after setting e.style['" + property + "'] = " + stringifiedValue);
+}
+
+function assert_invalid_value(property, value) {
+    var stringifiedValue = JSON.stringify(value);
+
+    test(function(){
+        var div = document.createElement('div');
+        div.style[property] = value;
+        assert_equals(div.style[property], "");
+    }, "e.style['" + property + "'] = " + stringifiedValue + " should not set the value");
+}