gecko/dom/promise/tests/test_thenable_vs_promise_ordering.html

28 lines
1.1 KiB
HTML

<!DOCTYPE html>
<meta charset=utf-8>
<title>Test for promise resolution ordering with thenables and promises</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
var t = async_test("A promise resolved first (with a thenable) should trigger its callbacks before a promise resolved second (with a promise).");
t.step(function() {
var customThenCalled = false;
var p0 = Promise.resolve();
p0.then = function(resolved, rejected) {
customThenCalled = true;
Promise.prototype.then.call(this, resolved, rejected);
}
var p1 = new Promise(function(r) { r(p0); });
delete p0.then;
var p2 = new Promise(function(r) { r(p0); });
var resolutionOrder = "";
Promise.all([ p1.then(function() { resolutionOrder += "1"; }),
p2.then(function() { resolutionOrder += "2"; }) ])
.then(t.step_func_done(function() {
assert_true(customThenCalled, "Should have called custom then");
assert_equals(resolutionOrder, "12");
}));
});
</script>