1 files changed, 18 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/support/query-testcommon.js b/testing/web-platform/tests/css/support/query-testcommon.js
new file mode 100644
index 0000000000..73246e17e8
--- /dev/null
+++ b/testing/web-platform/tests/css/support/query-testcommon.js
@@ -0,0 +1,18 @@
+'use strict';
+
+function test_query_selector(parentNode, selector, expected) {
+  if (!Array.isArray(expected))
+    expected = [ expected ];
+
+  test(function(){
+    const elementList = parentNode.querySelectorAll(selector);
+    assert_equals(elementList.length, expected.length);
+
+    for (let i = 0; i < elementList.length; ++i) {
+      if (typeof expected[i] === 'string')
+        assert_equals(elementList[i].id, expected[i]);
+      else
+        assert_equals(elementList[i], expected[i]);
+    }
+  }, "Selector '" + selector + '" should find the expected elements');
+}