How to get the status code of a CORS http failed preflight requets

user_985454 0
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Is it possible to get the error code of a failed preflight request so that I can print a meaningful error message? (Or is there a habit of printing a static error for all failed preflight requests no matter the code?)

Clearly, the status code 401 is printed to the console, but the error handler or a .catch() statement only receive the error object thrown. with preflight

If I remove the header that triggers the preflight, I get to handle the response myself and I can extract the status code. without preflight

// also note that the returned code 401 in first screenshot is wrong. But that's another question..

preflight http-status-codes cors javascript
2 Answers

No, it isn't.

If the status code of the preflight response is not 200, then the Same Origin Policy will prevent any information about the response from being extracted from it.

I've just finished setting up a web API to always return 200 OK status for OPTIONS requests for this reason.

Dorward_190680

Unfortunately not. All fetch returns is a TypeError with message "Failed to fetch".

> fetch('https://stackexchange.com/404').then(x => console.info(x), error => console.error(error))
× TypeError: Failed to fetch

I tried to manually send another preflight-request and grab the response code of that.

> fetch('https://stackexchange.com/404', { method: 'OPTIONS' }).then(x => console.info(x), error => console.error(error))
× TypeError: Failed to fetch

But that just triggers another preflight and still doesn't let me at the actual failed request.

user_11712270
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