[ DOCS ] Vue component testing/events (#4953)

Co-authored-by: Lachlan Miller <lachlan.miller.1990@outlook.com>
Co-authored-by: Emily Rohrbough <emilyrohrbough@users.noreply.github.com>

Author: 3 people

docs/guides/component-testing/vue/quickstart.mdx

@@ -376,8 +376,10 @@ it('clicking + fires a change event with the incremented value', () => {
 First, we create a new spy by calling the `cy.spy()` method. We pass in a string
 that gives the spy an [alias](/guides/core-concepts/variables-and-aliases),
 which assigns the spy a name by which we can reference it later. In
-`cy.mount()`, we initialize the component and pass the spy into it. After that,
-we click the increment button.
+`cy.mount()`, we initialize the component and pass the spy into it (note that
+while the event is defined as `change`, the spy is passed for the prop
+`onChange`; this is due to the fact that Vue compiles `emit('change')` to
+`props.onChange()`). After that, we click the increment button.
 
 The next line is a bit different. We've seen how we can use the `cy.get()`
 method to select elements, but we can also use it to grab any aliases we've set