1 files changed, 12 insertions, 6 deletions
diff --git a/tests/wpt/web-platform-tests/css/css-transforms/parsing/resources/parsing-testcommon.js b/tests/wpt/web-platform-tests/css/css-transforms/parsing/resources/parsing-testcommon.js
index 688356bd0f9..9427f53d81b 100644
--- a/tests/wpt/web-platform-tests/css/css-transforms/parsing/resources/parsing-testcommon.js
+++ b/tests/wpt/web-platform-tests/css/css-transforms/parsing/resources/parsing-testcommon.js
@@ -1,5 +1,8 @@
 'use strict';
 
+// serializedValue can be the expected serialization of value,
+// or an array of permitted serializations,
+// or omitted if value should serialize as value.
 function test_valid_value(property, value, serializedValue) {
     if (arguments.length < 3)
         serializedValue = value;
@@ -9,17 +12,20 @@ function test_valid_value(property, value, serializedValue) {
     test(function(){
         var div = document.createElement('div');
         div.style[property] = value;
-        assert_not_equals(div.style[property], "");
-    }, "e.style['" + property + "'] = " + stringifiedValue + " should set the property value");
+        assert_not_equals(div.style[property], "", "property should be set");
 
-    test(function(){
         var div = document.createElement('div');
         div.style[property] = value;
         var readValue = div.style[property];
-        assert_equals(readValue, serializedValue);
+        if (serializedValue instanceof Array)
+            assert_true(serializedValue.includes(readValue), "serialization should be sound");
+        else
+            assert_equals(readValue, serializedValue, "serialization should be canonical");
+
         div.style[property] = readValue;
-        assert_equals(div.style[property], readValue);
-    }, "Serialization should round-trip after setting e.style['" + property + "'] = " + stringifiedValue);
+        assert_equals(div.style[property], readValue, "serialization should round-trip");
+
+    }, "e.style['" + property + "'] = " + stringifiedValue + " should set the property value");
 }
 
 function test_invalid_value(property, value) {