Will Tebbutt

> Do we introduce a max-depth parameter? what does it default to? I wasn't imagining doing this -- usually if I want a structural tangent I just want everything to...

> Sometimes we test them if we want to be sure one is defined, or that it has the right sig. Agreed -- I think this + avoiding regressions is...

Could you provide a stack trace please? :)

Oh weird, yeah, that sounds like a bug.

I think you're correct, although for `frule_test` you would want to accept a tangent for the output.

> Testing generic code more deeply is a great idea, but I'd vote for a less adversarial phrasing phrasing here. We're not trying to keep hackers away from some automated...

I like this approach. One quick question though: how do you envision ensuring an author that a certain combination of things get tested? Manually call `rrule_test`?

> I'm not sure I follow, but I was not envisaging providing a way to specify an arbitrary list of types. You could still test any one particular weird thing...

Oh I see. Good question. With your gist as it currently is, I agree that it makes sense to have a few different modes. However, if you were to refactor...

Ohh I see. Maybe these tests need to be able to operate in either of two modes then: 1. limited scope: all types must return a rule, all rules must...