A question about test factories and variable initi...

# kotest

[Klitos Kyriacou]

A question about test factories and variable initializations (🧵)

[Klitos Kyriacou]

I have a test like this:

class MyTest : FreeSpec({
    val x = foo()
    val y = bar()
    val z = baz()

    "container a" - {
        "test1" {}
        "test2" {}
    }

    "container b" - {
        "test1" {}
        "test2" {}
    }
})

To eliminate code duplication, I used a test factory:

class MyTest : FreeSpec({
    include(factory("a"))
    include(factory("b"))
})

private fun factory(s: String) = freeSpec {
    val x = foo()
    val y = bar()
    val z = baz()

    "container $s" - {
        "test1" {}
        "test2" {}
    }
}

Unfortunately, the code using a test factory is not functionally equivalent, because foo(), bar() and baz() are called twice (once per factory inclusion).

I can change it so that x, y and z are initialized just once, in the FreeSpec constructor call, and passed as parameters to the factory. However, in the real application, there are too many such local variables and it would be unwieldy to pass so many parameters.

Is there a recommended best practice for such a situation?