DO NOT MERGE: First draft of potential API adjustments

[tonyandrewmeyer]

A discussion starting point.

[benhoyt]

I've gone through this for our discussion this afternoon. Some of my comments are terse -- that's not me being short with you, just got sick of typing so much! :-)

[benhoyt]

Again, not related to this change, but IMO this would be clearer without introducing parametrized tests here, just as two dumb, hard-coded tests:

def test_status_leader():
    ctx = scenario.Context(MyCharm, meta={"name": "foo"})
    out = ctx.run(MyCharm.on.start, scenario.State(leader=True))
    assert out.unit_status == ops.ActiveStatus('I rule')

def test_status_non_leader():
    ctx = scenario.Context(MyCharm, meta={"name": "foo"})
    out = ctx.run(MyCharm.on.start, scenario.State(leader=False))
    assert out.unit_status == ops.ActiveStatus('I am ruled')

[benhoyt]

Normally Scenario users won't need this meta={...} param, as it'll be picked up automatically. Can we remove it in the examples? Longer-term, we should probably use doctests or something so these examples are runnable.

[benhoyt]

Agreed!

[tonyandrewmeyer]

Can we make either of these possible?

assert isinstance(state.out.deferred[0], ops.StartEvent)
assert isinstance(state.out.deferred[0].event, ops.StartEvent)     # state.out.deferred[0]: DeferredEvent