Expose event for when Cypress is about to exit

[stahloss]

We have a process that starts up when Cypress does, which we start from the Cypress plugins index.js, using NodeJS's child_process. The process is Wiremock, to be exact. We know we can use Cypress' fixtures, but for now this is not an option.

We would like an event to be implemented that we can bind to so we can kill the child_process when Cypress is about to exit.

On Windows the child_process is killed automatically, but on Linux it needs to be manually stopped, because it keeps running even after the parent process is killed.

[jennifer-shehane]

You can have more debug logs log, by running DEBUG=cypress:server:cypress cypress run. This will issue a debug log when it's about to exit, but...I don't think you could actually prevent the exit code in this case.

Have you looked at our Module API? It may be a medium where you can craft something you want.

[stahloss]

Thanks I will have a look at the module API.

But lifecycle events are always useful and it seems easy to fire an event when it's about to exit (maybe where it's logged)?
Then if listeners are registered, wait for their promises to resolve, else just exit?

[jennifer-shehane]

Even if easy to implement, there are many considerations when deciding what to put into the product beside its ease of implementation. We'll leave this issue as a proposal and see if this issue gains more 👍 or comments in support from other users.

This would likely fall under the work slated for #2840

[rsudarson]

+1. This is a useful feature.

[chrisbreiding]

This is now supported by using the after:run event. You currently need to enable it with the experimentalRunEvents option, but that will no longer be necessary when Cypress 6.7.0 is released in the near future.

[jennifer-shehane]

This issue will be closed to further comment as the exact issue here was resolved and tested.

If you're experiencing a bug similar to this in Cypress, please open a new issue with a fully reproducible example that we can run. There may be a specific edge case with the issue that we need more detail to fix.