Investigate automatically generating stubs

[nchevobbe]

copied from https://bugzilla.mozilla.org/show_bug.cgi?id=1312177

In the majority of the Reps tests, we directly pass a manually retrieved stub to the component. It is great because the tests are fasts. However, it means that if there are some changes on the backend, the stubs will be out of sync, which might lead to bugs that wouldn't be caught by the tests.
We should have a system to generate the stubs, like we do it in the new console, so there are always synced.
Maybe we could shared all or some of the logic of the console at some point.

[nchevobbe]

I wonder if we couldn't have a devtools-stubs (or devtools-fixture, or something else) package here in devtools core.
This would be hooked up with CircleCI and a cron task (a mochitest that would check if the stubs in the repo would change if we generate them again).
Then we would be able to require those stubs from anywhere (reps, devtools-component, debugger-html, …).
The idea isn't fully formed in my head, but I think we could have something nice and useful for all the devtools panels.

[nchevobbe]

This issue was moved to firefox-devtools/debugger#6149