1590301 - window.TouchEvent should be `undefined` when touch simulation is off in RDM

Status: NEW

(DevTools :: Responsive Design Mode, defect, P3)

Description

[Patrick Brosset <:pbro>]

STR:

1. Make sure devtools.responsive.touchSimulation.enabled is false
2. Open a site
3. Open RDM
4. Make sure the reload when touch simulation is toggled setting is off in RDM
5. Evaluate window.TouchEvent in the console ==> undefined
6. Click the touch simulation button
7. Evaluate window.TouchEvent in the console ==> function
8. Click the touch simulation button to uncheck it
9. Evaluate window.TouchEvent again ==> still function

Comment 1

[Brad Werth [:bradwerth]]

Seems like we should make a clear decision about desired behavior here. Should TouchEvent constructor always be available or only conditionally available? My vote is that the constructor should always be available. I don't see anything in the spec (https://www.w3.org/TR/touch-events) that indicates otherwise. I'll proceed with that intention.

Comment 2

[Brad Werth [:bradwerth]]

Code is changing in this space. This will need a re-test after Bug 1588438 lands.

Comment 3

[Dan Burzo]

I think the TouchEvent interface should be always available, as it would be much simpler to write e instanceof TouchEvent than check that its type matches. Should I open a separate issue for this discussion?