Result4k Kotest Matchers

Hello there. I’ve recently decided to migrate one of my projects from Arrow to Result4k as all I really need is a Result type. The one thing I miss though are Kotest matchers like shouldBeInvalid, shouldBeValid, shouldBeLeft etc. and I couldn’t find anything out of the box for Result4k!

Would this project be interested in a Kotest module? I’ve made a draft one here under the Result4k folder which provides various shouldBeSuccess and shouldBeFailure functions, usage looks like:

fun exampleDivideByZero() {
    val result = divide(5, 0) //function that returns Failure upon divide by zero

    //all of these would pass
    result.shouldBeFailure()
    result shouldBeFailure DivideByZeroFailure
    result shouldBeFailure { reason ->
        reason shouldBe DivideByZeroFailure
    }

    //but this will fail with the appropriate message
    result shouldBeSuccess 5 //Throws AssertionError like: Failure(DivideByZero) should be Success(5)
}

If you’d rather keep stuff like this out of this repo I’d be happy to just maintain this in a separate repo as it’s pretty small in scope 😅

[MrBergin]

Ah I thought that might be the case! Will keep you posted.

[daviddenton]

Cool. We’ll put it into the readme. 😃