The test has been through a major refactor, lifting out common parts, improving
comments, and naming.
Signed-off-by: Gergely Nagy <algernon@keyboard.io>
The new test case exercises a few corners of the system: we test that without
any layer changes, we start out on the right one. We also test that shifting to
another layer preserves the current caching behaviour. We test that the layers
are indeed looped through in activation order, rather than index order. And
finally, we test that explicitly turning off the single active layer will have
us fall back to layer 0.
We only test layer shifts, not locks and moves, because we only changed the
ordering, not how those behave otherwise.
Signed-off-by: Gergely Nagy <algernon@keyboard.io>