Bug 1503596 [wpt PR 13813] - Add assert_not_own_property, a=testonly

Automatic update from web-platform-testsAdd assert_not_own_property (#13813)

Fixed #13186
--

wpt-commits: 679a364421ce3704289df21e1ff985c14b360981
wpt-pr: 13813

testing/web-platform/tests/docs/_writing-tests/testharness-api.md

@@ -758,6 +758,9 @@ asserts that the class string of `object` as returned in
 ### `assert_own_property(object, property_name, description)`
 assert that object has own property `property_name`
 
+### `assert_not_own_property(object, property_name, description)`
+assert that object does not have an own property named `property_name`
+
 ### `assert_inherits(object, property_name, description)`
 assert that object does not have an own property named
 `property_name` but that `property_name` is present in the prototype

testing/web-platform/tests/resources/test/tests/functional/api-tests-1.html

@@ -148,10 +148,10 @@
         A.prototype = {b:"b"}
         var a = new A();
         assert_own_property(a, "a");
-        assert_false(a.hasOwnProperty("b"), "unexpected property found: \"b\"");
+        assert_not_own_property(a, "b", "unexpected property found: \"b\"");
         assert_inherits(a, "b");
     }
-    test(testAssertInherits, "test for assert[_not]_exists and insert_inherits")
+    test(testAssertInherits, "test for assert[_not]_own_property and insert_inherits")
 
     test(function()
     {
@@ -398,7 +398,7 @@
     },
     {
       "status_string": "PASS",
-      "name": "test for assert[_not]_exists and insert_inherits",
+      "name": "test for assert[_not]_own_property and insert_inherits",
       "message": null,
       "properties": {}
     },

testing/web-platform/tests/resources/testharness.js

@@ -1262,6 +1262,13 @@ policies and contribution forms [3].
     }
     expose(assert_own_property, "assert_own_property");
 
+    function assert_not_own_property(object, property_name, description) {
+        assert(!object.hasOwnProperty(property_name),
+               "assert_not_own_property", description,
+               "unexpected property ${p} is found on object", {p:property_name});
+    }
+    expose(assert_not_own_property, "assert_not_own_property");
+
     function _assert_inherits(name) {
         return function (object, property_name, description)
         {