Bug 124066 – Uncaught exceptions raised in promise completion functions are not printed to console

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: Web Inspector

[Alexey Proskuryakov]

Created attachment 216429 [details]
test case

E.g.

crypto.subtle.generateKey({name: "hmac", hash: "sha-1"}, true, ["sign", "verify"]).then(function(result) {
    throw("See me?");
});

Marking this as blocking WebCrypto, because it's super difficult to use WebCrypto form JS when uncaught exceptions are not visible in Inspector. In fact, this is even slowing down writing tests for me, even though I'm only targeting WebKit, and know what and when raises exceptions.

[Alexey Proskuryakov]

Created attachment 218241 [details]
another test case

A test case that doesn't use WebCrypto.

What happens here is when JSPromiseWrapperCallback::callPromiseWrapperCallback() sees an exception, it immediately clears it, and invokes resolver's reject callback with the exception as argument. But when there are no reject callbacks registered, it's just dropped on the floor.

Perhaps the exception shouldn't be cleared when there are no reject callbacks to handle it, and then JSGlobalObjectCallback could report it in the same way as other code that executes JS does. ScriptController::evaluateInWorld() and JSEventListener::handleEvent() seem like they could serve as models.

[Joseph Pecoraro]

This sounds bad! The Web Inspector should know about all exceptions.

[Radar WebKit Bug Importer]

<rdar://problem/17920074>

[Joseph Pecoraro]

There is already some work in this area on bug 150358.

With the HTML Spec's unhandledpromiserejection / rejectionhandled events.

[Joseph Pecoraro]

This was addressed by: bug 150358

• The first test case is outdated (there is no Promise.fulfill anymore)
• The second test case produces:
[Error] Unhandled Promise Rejection: See me?

*** This bug has been marked as a duplicate of bug 150358 ***