Import wpt@9fcccf38b6be00f71ffa6bd6e29c5aa1ef25ee8c

third_party/WebKit/LayoutTests/imported/wpt/resources/testharness.js

 /*global self*/
 /*jshint latedef: nofunc*/
 /*
 Distributed under both the W3C Test Suite License [1] and the W3C
 3-clause BSD License [2]. To contribute to a W3C Test Suite, see the
 policies and contribution forms [3].
 
 [1] http://www.w3.org/Consortium/Legal/2008/04-testsuite-license
 [2] http://www.w3.org/Consortium/Legal/2008/03-bsd-license
 [3] http://www.w3.org/2004/10/27-testcases
@@ skipping 509 matching lines @@
         return test_obj;
     }
 
     function promise_test(func, name, properties) {
         var test = async_test(name, properties);
         // If there is no promise tests queue make one.
         if (!tests.promise_tests) {
             tests.promise_tests = Promise.resolve();
         }
         tests.promise_tests = tests.promise_tests.then(function() {
-            return Promise.resolve(test.step(func, test, test))
+            var promise = test.step(func, test, test);
+            test.step(function() {
+                assert_not_equals(promise, undefined);
+            });
+            return Promise.resolve(promise)
                 .then(
                     function() {
                         test.done();
                     })
                 .catch(test.step_func(
                     function(value) {
                         if (value instanceof AssertionError) {
                             throw value;
                         }
                         assert(false, "promise_test", null,
@@ skipping 2138 matching lines @@
             tests.status.status = tests.status.ERROR;
             tests.status.message = e.message;
             tests.status.stack = e.stack;
         }
     });
 
     test_environment.on_tests_ready();
 
 })();
 // vim: set expandtab shiftwidth=4 tabstop=4: