Allow listening for remote automation events

[Andarist]

User facing changelog

Cypress.automation accepts a new remote:debugger:event' command. This allows you to listen for remote automation events like Page.javascriptDialogOpening.

Additional details

I'd like to test stuff like native browser dialogs. It's impossible without being able to hook into an event like Page.javascriptDialogOpening

How has the user experience changed?

This introduces a new capability for advanced users.

PR Tasks

If this PR gets green light from your team then I could work on the remaining tasks.

• Have tests been added/updated?
• Has a PR for user-facing changes been opened in cypress-documentation?
• Have API changes been updated in the type definitions?

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[Andarist]

@jennifer-shehane I see that you have assigned me to this PR - does this mean that I should work on the remaining items from the list?

[flotwig]

remote:debugger:protocol was added for internal testing, but since we actually have consumers of these APIs, can you add some tests for remote:debugger:event and remote:debugger:protocol please? You could add them as server unit tests in packages/server/test/unit/browsers/cdp_automation_spec.ts.

[flotwig]

I understand why you want to add this. For additional context, we are planning to add official CDP support through a nicer API in the future, see this comment for some ideas.

One part that is TBD is how the planned API will handle selecting CDP Targets. To make your change forward-compatible with the future feature, can you add a targetId to the callback to indicate that this event is originating from Cypress's main CDP Target? Like, instead of calling data.callback with the raw eventData, call it with { targetId: 'main', eventData }, or something like that.

That way we can add CDP Target selection in a future PR that is forward-compatible with this change (for #7942). For the Cypress-owned Target, targetId could be main, for all others it could be the targetId returned by Target.createTarget.

[jennifer-shehane]

Unfortunately we have to close this PR due to inactivity. Please open a new PR addressing the original issue and any requested changes.