Implement onunhandledrejection / onrejectionhandled events

LayoutTests/fast/dom/resources/promise-rejection-events.js

Index: LayoutTests/fast/dom/resources/promise-rejection-events.js
diff --git a/LayoutTests/fast/dom/resources/promise-rejection-events.js b/LayoutTests/fast/dom/resources/promise-rejection-events.js
new file mode 100644
index 0000000000000000000000000000000000000000..d5e1f8f0b653af7c7b1d5b15b190dccb465c3f11
--- /dev/null
+++ b/LayoutTests/fast/dom/resources/promise-rejection-events.js
@@ -0,0 +1,439 @@
+'use strict';
+if (self.importScripts) {
+  self.importScripts('../../../resources/testharness.js');
+}
+//

[domenic, 2015/06/16 15:42:36]

You killed all my nice separating newlines :(

[jochen (gone - plz use gerrit), 2015/06/16 18:08:18]

I blame this on paste... I'll put them back in

+// Straightforward unhandledrejection tests
+//
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.reject(e);
+}, 'unhandledrejection: from Promise.reject');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = new Promise(function(_, reject) {
+    reject(e);
+  });
+}, 'unhandledrejection: from a synchronous rejection in new Promise');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = new Promise(function(_, reject) {
+    postMessageTask(function() {
+      reject(e);
+    });
+  });
+}, 'unhandledrejection: from a task-delayed rejection');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = new Promise(function(_, reject) {
+    setTimeout(function() {
+      reject(e);
+    }, 1);
+  });
+}, 'unhandledrejection: from a setTimeout-delayed rejection');
+async_test(function(t) {
+  var e = new Error();
+  var e2 = new Error();
+  var promise2;
+  onUnhandledSucceed(t, e2, function() { return promise2; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  promise2 = Promise.reject(e).then(unreached, function(reason) {
+    t.step(function() {
+      assert_equals(reason, e);
+    });
+    throw e2;
+  });
+}, 'unhandledrejection: from a throw in a rejection handler chained off of Promise.reject');
+async_test(function(t) {
+  var e = new Error();
+  var e2 = new Error();
+  var promise2;
+  onUnhandledSucceed(t, e2, function() { return promise2; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  promise2 = new Promise(function(_, reject) {
+    setTimeout(function() {
+      reject(e);
+    }, 1);
+  }).then(unreached, function(reason) {
+    t.step(function() {
+      assert_equals(reason, e);
+    });
+    throw e2;
+  });
+}, 'unhandledrejection: from a throw in a rejection handler chained off of a setTimeout-delayed rejection');
+async_test(function(t) {
+  var e = new Error();
+  var e2 = new Error();
+  var promise2;
+  onUnhandledSucceed(t, e2, function() { return promise2; });
+  var promise = new Promise(function(_, reject) {
+    setTimeout(function() {
+      reject(e);
+      postMicroTask(function() {
+        var unreached = t.unreached_func('promise should not be fulfilled');
+        promise2 = promise.then(unreached, function(reason) {
+          t.step(function() {
+            assert_equals(reason, e);
+          });
+          throw e2;
+        });
+      });
+    }, 1);
+  });
+}, 'unhandledrejection: from a throw in a rejection handler attached one microtask after a setTimeout-delayed rejection');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.resolve().then(function() {
+    return Promise.reject(e);
+  });
+}, 'unhandledrejection: from returning a Promise.reject-created rejection in a fulfillment handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.resolve().then(function() {
+    throw e;
+  });
+}, 'unhandledrejection: from a throw in a fulfillment handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.resolve().then(function() {
+    return new Promise(function(_, reject) {
+      setTimeout(function() {
+        reject(e);
+      }, 1);
+    });
+  });
+}, 'unhandledrejection: from returning a setTimeout-delayed rejection in a fulfillment handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.all([Promise.reject(e)]);
+}, 'unhandledrejection: from Promise.reject, indirected through Promise.all');
+//
+// Negative unhandledrejection/rejectionhandled tests with immediate attachment
+//
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  p = Promise.reject(e).then(unreached, function() {});
+}, 'no unhandledrejection/rejectionhandled: rejection handler attached synchronously to a promise from Promise.reject');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  p = Promise.all([Promise.reject(e)]).then(unreached, function() {});
+}, 'no unhandledrejection/rejectionhandled: rejection handler attached synchronously to a promise from ' +
+   'Promise.reject, indirecting through Promise.all');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  p = new Promise(function(_, reject) {
+    reject(e);
+  }).then(unreached, function() {});
+}, 'no unhandledrejection/rejectionhandled: rejection handler attached synchronously to a synchronously-rejected ' +
+   'promise created with new Promise');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  p = Promise.resolve().then(function() {
+    throw e;
+  }).then(unreached, function(reason) {
+    t.step(function() {
+      assert_equals(reason, e);
+    });
+  });
+}, 'no unhandledrejection/rejectionhandled: rejection handler attached synchronously to a promise created from ' +
+   'throwing in a fulfillment handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  p = Promise.resolve().then(function() {
+    return Promise.reject(e);
+  }).then(unreached, function(reason) {
+    t.step(function() {
+      assert_equals(reason, e);
+    });
+  });
+}, 'no unhandledrejection/rejectionhandled: rejection handler attached synchronously to a promise created from ' +
+   'returning a Promise.reject-created promise in a fulfillment handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  var unreached = t.unreached_func('promise should not be fulfilled');
+  p = Promise.resolve().then(function() {
+    return new Promise(function(_, reject) {
+      setTimeout(function() {
+        reject(e);
+      }, 1);
+    });
+  }).then(unreached, function(reason) {
+    t.step(function() {
+      assert_equals(reason, e);
+    });
+  });
+}, 'no unhandledrejection/rejectionhandled: rejection handler attached synchronously to a promise created from ' +
+   'returning a setTimeout-delayed rejection in a fulfillment handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  postMessageTask(function() {
+    p = Promise.resolve().then(function() {
+      return Promise.reject(e);
+    })
+    .catch(function() {});
+  });
+}, 'no unhandledrejection/rejectionhandled: all inside a queued task, a rejection handler attached synchronously to ' +
+   'a promise created from returning a Promise.reject-created promise in a fulfillment handler');
+//
+// Negative unhandledrejection/rejectionhandled tests with delayed attachment
+//
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  p = Promise.reject(e);
+  postMicroTask(function() {
+    var unreached = t.unreached_func('promise should not be fulfilled');
+    p.then(unreached, function() {});
+  });
+}, 'delayed handling: a microtask delay before attaching a handler prevents both events (Promise.reject-created ' +
+   'promise)');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledFail(t, function() { return p; });
+  p = new Promise(function(_, reject) {
+    reject(e);
+  });
+  postMicroTask(function() {
+    var unreached = t.unreached_func('promise should not be fulfilled');
+    p.then(unreached, function() {});
+  });
+}, 'delayed handling: a microtask delay before attaching a handler prevents both events (immediately-rejected new ' +
+   'Promise-created promise)');
+async_test(function(t) {
+  var e = new Error();
+  var p1;
+  var p2;
+  onUnhandledFail(t, function() { return p1; });
+  onUnhandledFail(t, function() { return p2; });
+  p1 = new Promise(function(_, reject) {
+    postMicroTask(function() {
+      reject(e);
+    });
+  });
+  p2 = Promise.all([p1]);
+  postMicroTask(function() {
+    var unreached = t.unreached_func('promise should not be fulfilled');
+    p2.then(unreached, function() {});
+  });
+}, 'delayed handling: a microtask delay before attaching the handler, and before rejecting the promise, indirected ' +
+   'through Promise.all');
+//
+// Positive unhandledrejection/rejectionhandled tests with delayed attachment
+//
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  var _reject;
+  p = new Promise(function(_, reject) {
+    _reject = reject;
+  });
+  _reject(e);
+  postMessageTask(function() {
+    var unreached = t.unreached_func('promise should not be fulfilled');
+    p.then(unreached, function() {});
+  });
+}, 'delayed handling: a task delay before attaching a handler does not prevent unhandledrejection');
+async_test(function(t) {
+  var unhandledPromises = [];
+  var unhandledReasons = [];
+  var e = new Error();
+  var p;
+  var unhandled = function(ev) {
+    if (ev.promise === p) {
+      t.step(function() {
+        unhandledPromises.push(ev.promise);
+        unhandledReasons.push(ev.reason);
+      });
+    }
+  };
+  var handled = function(ev) {
+    if (ev.promise === p) {
+      t.step(function() {
+        assert_array_equals(unhandledPromises, [p]);
+        assert_array_equals(unhandledReasons, [e]);
+        assert_equals(ev.promise, p);
+        assert_equals(ev.reason, e);
+      });
+    }
+  };
+  addEventListener('unhandledrejection', unhandled);
+  addEventListener('rejectionhandled', handled);
+  ensureCleanup(t, unhandled, handled);
+  p = new Promise(function() {
+    throw e;
+  });
+  setTimeout(function() {
+    var unreached = t.unreached_func('promise should not be fulfilled');
+    p.then(unreached, function(reason) {
+      assert_equals(reason, e);
+      setTimeout(function() { t.done(); }, 10);
+    });
+  }, 10);
+}, 'delayed handling: delaying handling by setTimeout(,10) will cause both events to fire');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.reject(e);
+  postMessageTask(function() {
+    Promise.resolve().then(function() {
+      p.catch(function() {});
+    });
+  });
+}, 'delayed handling: postMessageTask after promise creation/rejection, plus promise microtasks, is too late to ' +
+   'attach a rejection handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  postMessageTask(function() {
+    Promise.resolve().then(function() {
+      Promise.resolve().then(function() {
+        Promise.resolve().then(function() {
+          Promise.resolve().then(function() {
+            p.catch(function() {});
+          });
+        });
+      });
+    });
+  });
+  p = Promise.reject(e);
+}, 'delayed handling: postMessageTask before promise creation/rejection, plus many promise microtasks, is too late ' +
+   'to attach a rejection handler');
+async_test(function(t) {
+  var e = new Error();
+  var p;
+  onUnhandledSucceed(t, e, function() { return p; });
+  p = Promise.reject(e);
+  postMessageTask(function() {
+    Promise.resolve().then(function() {
+      Promise.resolve().then(function() {
+        Promise.resolve().then(function() {
+          Promise.resolve().then(function() {
+            p.catch(function() {});
+          });
+        });
+      });
+    });
+  });
+}, 'delayed handling: postMessageTask after promise creation/rejection, plus many promise microtasks, is too late ' +
+   'to attach a rejection handler');
+//
+// Miscellaneous tests about integration with the rest of the platform
+//
+async_test(function(t) {
+  var e = new Error();
+  var l = function(ev) {
+    var order = [];
+    postMicroTask(function() {
+      order.push(1);
+    });
+    setTimeout(function() {
+      order.push(2);
+      t.step(function() {
+        assert_array_equals(order, [1, 2]);
+      });
+      t.done();
+    }, 1);
+  };
+  addEventListener('unhandledrejection', l);
+  ensureCleanup(t, l);
+  Promise.reject(e);
+}, 'postMicroTask vs. postMessageTask ordering is not disturbed inside unhandledrejection events');
+//
+// HELPERS
+//
+function postMessageTask(f) {
+  if ('document' in self) {
+    var l = function() {
+      removeEventListener('message', l);
+      f();
+    };
+    addEventListener('message', l);
+    postMessage('abusingpostmessageforfunandprofit', '*');
+  } else {
+    setTimeout(function() { f(); }, 0);

[domenic, 2015/06/16 15:42:36]

Should use MessageChannel in workers.
https://github.com/YuzuJS/setImmediate/blob/master/setImmediate.js#L107-L119

[jochen (gone - plz use gerrit), 2015/06/17 07:57:53]

done

+  }
+}
+function postMicroTask(f) {
+  Promise.resolve().then(function() { f(); });

[domenic, 2015/06/16 15:42:36]

Kind of the point of the microtask tests is to test interaction of other
microtasks with promise microtasks. So this should stick with mutation observers
where possible. I guess in workers there are no other microtask sources so
Promise.resolve is fine.

[jochen (gone - plz use gerrit), 2015/06/16 18:08:18]

i'll put them back.

from an implementation point of view, that's a boring distinction, it's the same
microtask queue :)

+}
+function onUnhandledSucceed(t, expectedReason, expectedPromiseGetter) {
+  var l = function(ev) {
+    if (ev.promise === expectedPromiseGetter()) {

[domenic, 2015/06/16 15:42:36]

This if seems bad. If they mismatch, then the test should fail. Same here and
below.

[jochen (gone - plz use gerrit), 2015/06/16 18:08:18]

without this, none of the tests will work, as they all run in a single microtask
run.

if there's a promise that doesn't match any of the listeners, the resp. test
will just timeout.

+      t.step(function() {
+        assert_equals(ev.reason, expectedReason);
+        assert_equals(ev.promise, expectedPromiseGetter());
+      });
+      t.done();
+    }
+  };
+  addEventListener('unhandledrejection', l);
+  ensureCleanup(t, l);
+}
+function onUnhandledFail(t, expectedPromiseGetter) {
+  var unhandled = function(evt) {
+    if (evt.promise === expectedPromiseGetter()) {
+      t.unreached_func('unhandledrejection event is not supposed to be triggered');
+    }
+  };
+  var handled = function(evt) {
+    if (evt.promise === expectedPromiseGetter()) {
+      t.unreached_func('rejectionhandled event is not supposed to be triggered');
+    }
+  };
+  addEventListener('unhandledrejection', unhandled);
+  addEventListener('rejectionhandled', handled);
+  ensureCleanup(t, unhandled, handled);
+  setTimeout(function() {
+    t.done();
+  }, 10);
+}
+function ensureCleanup(t, unhandled, handled) {
+  t.add_cleanup(function() {
+    if (unhandled)
+      removeEventListener('unhandledrejection', unhandled);
+    if (handled)
+      removeEventListener('rejectionhandled', handled);
+  });
+}
+
+done();