1 files changed, 117 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/test-async.js b/deps/v8/test/mjsunit/test-async.js
new file mode 100644
index 0000000000..f8a11c5238
--- /dev/null
+++ b/deps/v8/test/mjsunit/test-async.js
@@ -0,0 +1,117 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+// Used for async tests. See definition below for more documentation.
+var testAsync;
+
+(function () {  // Scope for utility functions.
+  /**
+   * This is to be used through the testAsync helper function defined
+   * below.
+   *
+   * This requires the --allow-natives-syntax flag to allow calling
+   * runtime functions.
+   *
+   * There must be at least one assertion in an async test. A test
+   * with no assertions will fail.
+   *
+   * @example
+   * testAsync(assert => {
+   *   assert.plan(1) // There should be one assertion in this test.
+   *   Promise.resolve(1)
+   *    .then(val => assert.equals(1, val),
+   *          assert.unreachable);
+   * })
+   */
+  class AsyncAssertion {
+    constructor(test, name) {
+      this.expectedAsserts_ = -1;
+      this.actualAsserts_ = 0;
+      this.test_ = test;
+      this.name_ = name || '';
+    }
+
+    /**
+     * Sets the number of expected asserts in the test. The test fails
+     * if the number of asserts computed after running the test is not
+     * equal to this specified value.
+     * @param {number} expectedAsserts
+     */
+    plan(expectedAsserts) {
+      this.expectedAsserts_ = expectedAsserts;
+    }
+
+    fail(expectedText, found) {
+      let message = formatFailureText(expectedText, found);
+      message += "\nin test:" + this.name_
+      message += "\n" + Function.prototype.toString.apply(this.test_);
+      %AbortJS(message);
+    }
+
+    equals(expected, found, name_opt) {
+      this.actualAsserts_++;
+      if (expected !== found) {
+        this.fail(prettyPrinted(expected), found, name_opt);
+      }
+    }
+
+    unreachable() {
+      let message = "Failure: unreachable in test: " + this.name_;
+      message += "\n" + Function.prototype.toString.apply(this.test_);
+      %AbortJS(message);
+    }
+
+    unexpectedRejection(details) {
+      return (error) => {
+        let message =
+            "Failure: unexpected Promise rejection in test: " + this.name_;
+        if (details) message += "\n    @" + details;
+        if (error instanceof Error) {
+          message += "\n" + String(error.stack);
+        } else {
+          message += "\n" + String(error);
+        }
+        message += "\n\n" + Function.prototype.toString.apply(this.test_);
+        %AbortJS(message);
+      };
+    }
+
+    drainMicrotasks() {
+      %RunMicrotasks();
+    }
+
+    done_() {
+      if (this.expectedAsserts_ === -1) {
+        let message = "Please call t.plan(count) to initialize test harness " +
+            "with correct assert count (Note: count > 0)";
+        %AbortJS(message);
+      }
+
+      if (this.expectedAsserts_ !== this.actualAsserts_) {
+        let message = "Expected asserts: " + this.expectedAsserts_;
+        message += ", Actual asserts: " + this.actualAsserts_;
+        message += "\nin test: " + this.name_;
+        message += "\n" + Function.prototype.toString.apply(this.test_);
+        %AbortJS(message);
+      }
+    }
+  }
+
+  /** This is used to test async functions and promises.
+   * @param {testCallback} test - test function
+   * @param {string} [name] - optional name of the test
+   *
+   *
+   * @callback testCallback
+   * @param {AsyncAssertion} assert
+   */
+  testAsync = function(test, name) {
+    let assert = new AsyncAssertion(test, name);
+    test(assert);
+    %RunMicrotasks();
+    assert.done_();
+  }
+})();