CODEWITHSUNDEEP
angulartypescriptgoogle-chromepromise
Samuel Thompson
Samuel Thompson

Reputation: 2576

Uncaught (in promise) undefined

I am getting the following error in chrome, and have no idea where it is coming from: Error

The only thing that is really telling about anything is that I recently refactored about 10,000 lines of code and this error appeared some time in the middle of that. This is angular. I know how to catch promises, in angular. I am using an error handler to try and catch it but that did not work I also tried:

window.addEventListener('unhandledrejection', function (promiseRejectionEvent) {
  console.log(promiseRejectionEvent);
  console.log('here!!!!!')
});
window.onerror = function (promiseRejectionEvent) {
  console.log(promiseRejectionEvent);
  console.log('AHHHH')
};

Neither one of those caught the error. I have no idea where this error is coming from. It will appear every time I reload the page.

For the truly curious I have tried going to the link in chrome and it points to ... so not really helpful.

This error does not happen in firefox.

Upvotes: 6

Views: 15513

Answers (4)

Blockost
Blockost

Reputation: 563

As other responses suggest, try adding a breakpoint to where the stacktrace from the console points to. Then go up the call stack, and you probably find where a Promise is rejected in your code.

On my side, it was because we used Promise.reject() in a function without wrapping the call within a try/catch block. It worked fine until we added await to the function call, which triggered the unhandled promise exception and bubbled up to zone.js.

Upvotes: 0

Samuel Thompson
Samuel Thompson

Reputation: 2576

Try running your code in Incognito.

I found the answer and it was less than satisfactory. It was a Microsoft Office extension that was somehow injecting something that was getting half caught by zone.js, but kinda not. I have NO idea how that happened.

Finding the bug:

If you make chrome pause on exceptions then it WILL stop on this error. The error was in a content.js file which is not in my project so I said "hmm...". I then went to the location of the file by right clicking in the sources tab, and found that the error was in the Office extension. So if you get this Uncaught (in promise) undefined it is because somehow zone.js error handling is catching it. I have NO idea how, but try running your code in Incognito.

Upvotes: 1

Ling Vu
Ling Vu

Reputation: 5181

The error tells you that there is an error but you don´t catch it. Most probably you can check the responsible router for the route /app/outbound/cell-dial or any route guard function that relates to that.

For more information routing, but especially about router guards: https://angular.io/guide/router

Other options would be:

  • Reinstall your dependencies with
// Delete
rm -rf node_modules/
npm install

  • Check your repo diff from your last commit/merge/pull step by step

  • Check your versions, because there is a possibility that you have different dependency versions than before that wasn't setup properly.

In general this is how you can catch it (that you probably already know, but I still mention it just in case):

getAllPosts().then(response => {
    console.log(response);
}).catch(e => {
    console.log(e);
});

More information: https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Promise/catch

Or with async/await:

//some async function
try {
    let response = await getAllPosts();
} catch(e) {
    console.log(e);
}

Upvotes: 0

corolla
corolla

Reputation: 5656

The message Uncaught (in promise) is part of zone.js:

https://github.com/angular/zone.js/blob/master/lib/common/promise.ts#L194

Using chrome dev tools, either search all files (cmd/ctrl+shift+f) for this text or jump (cmd/ctrl + p) to zone.js and find 'Uncaught'. Put a breakpoint, reload page and inspect callstack once your breakpoint is hit.

Hope that'll point you in the right direction.

Upvotes: 7

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