Trying to come up with a test function to assert that every member of a list is of a specified type....

# getting-started

[Miguel Vargas]

Trying to come up with a test function to assert that every member of a list is of a specified type. This what I’ve tried

fun assertListTypes(list: List<ParentType>, types: List<KType>) {
    assertEquals(list.size, types.size)
    types.forEachIndexed { idx, type ->
        assert(list[idx] is type)
    }
}

assertListTypes(list, listOf(typeOf<Class1>(), typeOf<Class2>()))

But the compiler didn’t like the is check on the KType. Any ideas?

[mkrussel]

is checks can only be done with compile time constants on the right hand side.

Instead you have to use reflection functions to determine if it is that type.

[mkrussel]

KClass.isInstance could do that but I don't see anything on KType.

[Miguel Vargas]

thanks, let me try with KClass

[Miguel Vargas]

that worked!

[Miguel Vargas]

like this

fun assertListTypes(list: List<ParentType>, types: List<KClass<*>>) {
    assertEquals(list.size, types.size)
    types.forEachIndexed { idx, type ->
        assert(type.isInstance(list[idx]))
    }
}
    
assertListTypes(list, listOf(Class1::class, Class2::class))

[Miguel Vargas]

thanks for the help!

[Daniel]

The requirement seems fishy. What would speak against equals asserting against a expected list?