I have an analog to Arrow's `Either` type, and I'd really like to do something like ```val actual: ...

# kotest

[Jim]

I have an analog to Arrow's Either type, and I'd really like to do something like

val actual: <Unit, Errorish> = doThing()

withClue(lazy { "doThing error: ${actual.errorOrNull()?.message}" }) { 
  actual.isOk shouldBe true
}

Is this possible and I'm just not seeing a way in the current matchers? Basically I don't want to try to get the error message unless there's an error in my value

[Jim]

for context I can't use v0.x.x and therefore the kotest arrow integration until v1.0.0 which hopefully is coming soon per: https://www.47deg.com/blog/arrow-0-11-0-release/

[sam]

A clue that takes a lazy might be very nice

[Jim]

another thing for 4.4? 😈

[sam]

You're keeping me busy

[Jim]

😂 😅

[Jim]

Thought was brought to you by inspiration from kotlin's require and assert

[Jim]

Although it looks like asClue will pop every clue instead of only doing it when it fails, so it might need to be something similar to a clue, but not exactly

[Jim]

🤔

[sam]

asClue on lazy will work

[Jim]

(lazy { computeErrorMessage() }).asClue { 
  thing shouldBe true
}

like that?

[sam]

I mean that will work once we add it

[Jim]

ah 👍

[sam]

https://github.com/kotest/kotest/issues/1766

[Jim]

Is ErrorCollector part of the public facing api? I feel like changing pushClue to accept a Lazy<T> instead of a T is a breaking change

[sam]

It's not public, or shouldn't be

[sam]

its used internally

[Jim]

gotcha 👍

[Jim]

🤞 https://github.com/kotest/kotest/pull/1772