Just checking out Strikt. My previous preferred li...

# strikt

[rocketraman]

Just checking out Strikt. My previous preferred library was hamkrest. My first assertion is to validate the count of elements in a list. I see exactly, atMost, and atLeast , but all of these take an additional predicate. Is the preferred approach to do this?

expectThat(it).get { count() }.isEqualTo(3)

Is there any particular reason that there isn't a count matcher directly on list?

[robfletcher]

expectThat(it).hasSize(3) should work for you

[rocketraman]

Its actually an Iterable, not a List. No hasSize matcher seems to be available.

[robfletcher]

Okay, that’s because Iterable doesn’t define a size property. That’s added on Collection. It wouldn’t make sense for all iterables (they can be unbounded, for example). For your case expectThat(it.toList()).hasSize(3) is probably the way to go.

[robfletcher]

I mean, Strikt could add a hasSize for Assertion.Builder<Iterable<*>> but like I say it would not necessarily even make sense for every iterable

[rocketraman]

The Kotlin stdlib does have a count function on Iterable. Normally unbounded iterables are represented as a Sequence.

[robfletcher]

hmm, I could easily move hasSize up to work on Iterable I guess

[rocketraman]

I think that makes sense, based on the extensions available in stdlib. Want me to create a GH issue?

[robfletcher]

but it might make more sense to add a count() function so you could do expectThat(it).count().isEqualTo(3)

[robfletcher]

to make it clear what the underlying API mapping is

[rocketraman]

Makes sense to me

[rocketraman]

Out of curiosity, why does hasSize exist? Couldn't it work the same way?

[rocketraman]

Oh because List has a `size`property

[robfletcher]

yeah, well… Collection does

[robfletcher]

which is what count() delegates to if called on a Collection

[robfletcher]

otherwise it iterates over all the elements

[rocketraman]

Yup

[robfletcher]

I think the Strikt function would just be

fun Builder<out Iterable<*>>.count(): Builder<Int> =
  get(Iterable<*>::count)

[rocketraman]

I can confirm that worked. I was going to submit a PR but I see you beat me to it with a release of 0.28.1. 🙌