Cypress.on('uncaught:exception') receives CypressError instead of thrown error

Current behavior:

This might be a regression with Cypress 5.0.

I have a global catch for ResizeObserver loop limit exceeded in my support/index.js file.

const resizeObserverLoopErrRe = /^ResizeObserver loop limit exceeded/

Cypress.on('uncaught:exception', err => {
  if (resizeObserverLoopErrRe.test(err.message)) {
    return false
  }
})

As of version 5, I started noticing that when this error occurs, the handler will receive a CypressError instance, instead of the original error containing the above message. This therefore makes the tests fail, and returns the usual info message about this error:

The following error originated from your application code, not from Cypress.

  > ResizeObserver loop limit exceeded

When Cypress detects uncaught errors originating from your application it will automatically fail the current test.

This behavior is configurable, and you can choose to turn this off by listening to the `uncaught:exception` event.

https://on.cypress.io/uncaught-exception-from-application

Desired behavior:

The handler should receive the actual globally thrown error, as it previously did.

Test code to reproduce

https://github.com/vicrep/cypress-test-tiny/pull/1/files

Versions

Cypress: 5.0.0 Browser: Both on Electron and Chrome (didn’t test others) OS: Reproed on macOS and Linux

[hon2a]

@jennifer-shehane Please note that the regular expression you posted actually matches “any text starting with a character that is not one of () ORcdeilmoprstvxz” (all characters present in (ResizeObserver loop limit exceeded)), which is patently wrong and causes a lot of other errors to be possibly swallowed.

A simple way to safely-enough ignore just this specific error is:

Cypress.on('uncaught:exception', err => !err.message.includes('ResizeObserver loop limit exceeded'))

[jennifer-shehane]

We changed how the errors are constructed in 4.6.0+, you’ll need to upgrade your Regex to match the newly constructed error:

const resizeObserverLoopErrRe = /^[^(ResizeObserver loop limit exceeded)]/
Cypress.on('uncaught:exception', (err) => {
    /* returning false here prevents Cypress from failing the test */
    if (resizeObserverLoopErrRe.test(err.message)) {
        return false
    }
})