chore(webkit): working around WebKit bug by patching Error #23588
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Thanks for taking the time to open a PR!
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| let originalError = autWindow.Error | ||
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| autWindow.Error = function (...args) { | ||
| autWindow.queueMicrotask(() => {}) |
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Looking at this now, I wondered if this could backfire and cause an infinitely expanding queue, but I can't think of a scenario where that would happen where the user wouldn't already be doing infinite recursion anyways. So this seems safe enough...
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Ah, I thought of one - if window.queueMicrotask is monkey-patched to throw an Error itself, this would infinitely recurse. But that seems unlikely to happen in the wild. Maybe we could name this function something like __CyWebKitError so that it's at least identifiable in a stack trace in case someone does run in to this?
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That does seem unlikely, but naming the function is a good idea.
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Could even try...catch the queueMicrotask call... but... then that could also lead to really hard-to-debug issues ("why does my queueMicrotask monkey-patch make unhandled rejections not get caught by Cypress???"), so I think the way you have it is good for now. Let's see if any bug reports roll in.
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Test summary
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User facing changelog
N/A
Additional details
There were a few test cases within
uncaught_errors.cy.jsthat were failing for the WebKit browser. The errors that were being thrown and uncaught within a Promise chain were not being received by Cypress. The root cause can be found documented within a WebKit bug report here; it shows a minimal reproduction, which I can confirm with my own findings.A good bit of debugging and trial and error resulted in the work-around in this PR. It was found that any sort of operation executed after the Error was thrown would ensure that the proper error handlers would fire. A no-op microtask was chosen for this purpose, as it seems to have the smallest chance of impacting other functionality.
Steps to test
With this PR, all uncaught_errors specs will pass without any modification across our supported browsers.
How has the user experience changed?
PR Tasks
cypress-documentation?type definitions?