v8/test/mjsunit/es6/debug-promises/reject-uncaught-uncaught.js
littledan 013e49f73c Change which ExceptionEvents are triggered by Promises
To make async/await catch prediction work well, this patch regularizes
the exception events sent to DevTools from various places in the Promise
lifecycle. The core is that there should be an exception event when the
rejection first starts, rather than when it is propagated.

- Several cases within Promise code which propagate errors are
  modified to not trigger a new ExceptionEvent in that case, such
  as .then on a rejected Promise and returning a rejected Promise
  from .then, as well as Promise.race and Promise.all.
- Make Promise.reject() create an ExceptionEvent, subject to catch
  prediction based on the Promise stack. This is important
  so that, e.g., if "await Promise.reject()" will trigger a new
  throw (rather than a silent rethrow of something that never
  triggered an event in the first place).

BUG=v8:5167

Review-Url: https://codereview.chromium.org/2244003003
Cr-Commit-Position: refs/heads/master@{#38847}
2016-08-24 00:20:50 +00:00

67 lines
1.7 KiB
JavaScript

// Copyright 2014 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: --expose-debug-as debug --allow-natives-syntax
// Test debug events when we only listen to uncaught exceptions and
// there is no catch handler for the to-be-rejected Promise.
// We expect an Exception debug event with a promise to be triggered.
Debug = debug.Debug;
var expected_events = 1;
var log = [];
var p = new Promise(function(resolve, reject) {
log.push("resolve");
resolve();
});
var q = p.then(
function() {
log.push("reject");
return Promise.reject(Error("uncaught reject")); // event
});
function listener(event, exec_state, event_data, data) {
try {
if (event == Debug.DebugEvent.Exception) {
expected_events--;
assertTrue(expected_events >= 0);
assertEquals("uncaught reject", event_data.exception().message);
assertTrue(event_data.promise() instanceof Promise);
assertSame(q, event_data.promise());
assertTrue(event_data.uncaught());
// The JavaScript frame is from the Promise rejection
assertTrue(/Promise\.reject/.test(event_data.sourceLineText()));
}
} catch (e) {
%AbortJS(e + "\n" + e.stack);
}
}
Debug.setBreakOnUncaughtException();
Debug.setListener(listener);
log.push("end main");
function testDone(iteration) {
function checkResult() {
try {
assertTrue(iteration < 10);
if (expected_events === 0) {
assertEquals(["resolve", "end main", "reject"], log);
} else {
testDone(iteration + 1);
}
} catch (e) {
%AbortJS(e + "\n" + e.stack);
}
}
%EnqueueMicrotask(checkResult);
}
testDone(0);