i want to create a usually/sometimes statement for...

# getting-started

[tipsy]

i want to create a usually/sometimes statement for use with mock data. currently i have:

usually({

}, sometimes {

})

is it possible to get rid of the parens for usually somehow, so i just get:

usually {

} sometimes {

}

?

[Adam Powell]

make usually return something and sometimes an infix function with the UsuallyResult on the left hand side

[tipsy]

infix! thanks, will check that out

[wbertan]

fun usually(block: () -> Unit) = block()
    infix fun Unit.sometimes(block: () -> Unit) = block()
    
    @Test
    fun asas() {
        usually {
            
        } sometimes {
            
        }
    }

[tipsy]

well, that was fast

[tipsy]

thanks @wbertan!

[tipsy]

data class UsuallyResult(val usually: () -> Unit) {
    infix fun sometimes(sometimes: () -> Unit) {
        if (Math.random() < 0.8) {
            this.usually();
        } else {
            sometimes();
        }
    }
}

fun usually(usually: () -> Unit) = UsuallyResult(usually)

fun main() {
    usually {
        println("This should usually happen")
    } sometimes {
        println("But, sometimes this happens!")
    }
}

[tipsy]

any improvement suggestions, or is this okay?

[karelpeeters]

Looks good.

[karelpeeters]

I'm very curious, what is your use case for this? Usually (heh) unit tests are as deterministic as possible, right?

[tipsy]

usually when i write frontends, i tend to not prioritize error handling highly enough

[tipsy]

so i'm going to start writing mocked apis that sometimes fail

[tipsy]

to clarify, "having an error page" vs "making it feel okay to get an error" is not the same

[tipsy]

i want my mocked APIs to randomly fail so i can get a good understanding for how unexpected errors feel for a user

[karelpeeters]

I see.

[tipsy]

and i'm tired of writing Math.random everywhere, so i wanted to wrap it in a neat function