V8 Microtask Queue & API

test/mjsunit/harmony/microtask-delivery.js

+// Copyright 2012 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --harmony-observation --harmony-promises --allow-natives-syntax
+
+var ordering = [];
+function reset() {
+  ordering = [];
+}
+
+function assertArrayValues(expected, actual) {
+  assertEquals(expected.length, actual.length);
+  for (var i = 0; i < expected.length; i++) {
+    assertEquals(expected[i], actual[i]);
+  }
+}
+
+function assertOrdering(expected) {
+  %RunMicrotasks();
+  assertArrayValues(expected, ordering);
+}
+
+function newPromise(id, fn) {
+  var r;
+  var t = 1;
+  var promise = new Promise(function(resolve) {
+    r = resolve;
+    if (fn) fn();
+  });
+
+  var next = promise.then(function(value) {
+    ordering.push('p' + id);
+    return value;
+  });
+
+  return {
+    resolve: r,
+    then: function(fn) {
+      next = next.then(function(value) {
+        ordering.push('p' + id + ':' + t++);
+        return fn ? fn(value) : value;
+      });
+
+      return this;
+    }
+  };
+}
+
+function newObserver(id, fn, obj) {
+  var observer = {
+    value: 1,
+    recordCounts: []
+  };
+
+  Object.observe(observer, function(records) {
+    ordering.push('o' + id);
+    observer.recordCounts.push(records.length);
+    if (fn) fn();
+  });
+
+  return observer;
+}
+
+
+(function PromiseThens() {
+  reset();
+
+  var p1 = newPromise(1).then();
+  var p2 = newPromise(2).then();
+
+  p1.resolve();
+  p2.resolve();
+
+  assertOrdering(['p1', 'p2', 'p1:1', 'p2:1']);
+})();
+
+
+(function ObserversBatch() {
+  reset();
+
+  var p1 = newPromise(1);
+  var p2 = newPromise(2);
+  var p3 = newPromise(3);
+
+  var ob1 = newObserver(1);
+  var ob2 = newObserver(2, function() {
+    ob3.value++;
+    p3.resolve();
+    ob1.value++;
+  });
+  var ob3 = newObserver(3);
+
+  p1.resolve();
+  ob1.value++;
+  p2.resolve();
+  ob2.value++;
+
+  assertOrdering(['p1', 'o1', 'o2', 'p2', 'o1', 'o3', 'p3']);
+  assertArrayValues([1, 1], ob1.recordCounts);
+  assertArrayValues([1], ob2.recordCounts);
+  assertArrayValues([1], ob3.recordCounts);
+})();
+
+
+(function ObserversGetAllRecords() {
+  reset();
+
+  var p1 = newPromise(1);
+  var p2 = newPromise(2);
+  var ob1 = newObserver(1, function() {
+    ob2.value++;
+  });
+  var ob2 = newObserver(2);
+
+  p1.resolve();
+  ob1.value++;
+  p2.resolve();
+  ob2.value++;
+
+  assertOrdering(['p1', 'o1', 'o2', 'p2']);
+  assertArrayValues([1], ob1.recordCounts);
+  assertArrayValues([2], ob2.recordCounts);
+})();
+
+
+(function NewObserverDeliveryGetsNewMicrotask() {
+  reset();
+
+  var p1 = newPromise(1);
+  var p2 = newPromise(2);
+  var ob1 = newObserver(1);
+  var ob2 = newObserver(2, function() {
+    ob1.value++;
+  });
+
+  p1.resolve();
+  ob1.value++;
+  p2.resolve();
+  ob2.value++;
+
+  assertOrdering(['p1', 'o1', 'o2', 'p2', 'o1']);
+  assertArrayValues([1, 1], ob1.recordCounts);
+  assertArrayValues([1], ob2.recordCounts);
+})();