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kotlinlang

Hi! Wouldn't it be nice to have the Clock interface declared as a `fun interface`? That would allow very simple overriding of `now()` in unit tests... unless there are plans to add other functions to it?

Being a functional interface, `Clock` would allow passing lambdas where `Clock` is expected. This is certainly not how we would like the API with clocks to look like.
A helper constructor-like method could be introduced, though, e.g. `Clock(() -&gt; Instant)`

Yeah, I guess that's a good point! It's a bit easy to be trigger-happy with `fun interface`s :blush:! But the helper method would certainly be a nice addition... I find myself making it on every project's test utils...

What do you usually pass as a Clock in tests?

Usually an `Instant` `var`... since I need to modify it for certain tests in the same class. I use a base `Instant` and either subtract from it or add to it to modify the `now` `var` I passed in to clock.

It just exposes the instant in the constructor as a var and has functions like advanceBy(Duration)