Component Testing - How to trap event emit by component

[mariocardinal]

I'm submitting a request for a script example

I need to understand how I can trap the event emitted by a component. For example, let say I have a component with a button and when button is clicked it emit an event. I know how to automate click using cy.click() but how do I verify that the event was emit by the button.

[ ] Bug report
[ x] Content update
[ ] Process update (build, deployment, ... )

## Type of bug / changes

Add a section in Component Testing documentation about trapping component's event