Found this ticket but wonder if there’s any other ...

# announcements

[Kirill Zhukov]

Found this ticket but wonder if there’s any other way to achieve the same result? https://youtrack.jetbrains.com/issue/KT-28298

[Shawn]

is there a reason you can’t use a simple
if (obj is SomeType)?

[Shawn]

I’m not sure how this extension function would be used

[Kirill Zhukov]

This is to add smart cast support when doing assertions

[Kirill Zhukov]

If I have something like this:

interface Foo

object Bar : Foo {
  val name: String = "bar"
}

[Kirill Zhukov]

I want to be able to safely do assertion like this:

val foo: Foo = Bar
assertThat(foo).isInstanceOf<Bar>()
assertThat(foo.name).isEqualTo("bar")

[Kirill Zhukov]

similar to:

if (foo is Bar) {
  assertThat(foo.name).isEqualTo("bar")
}

[Kirill Zhukov]

but with instance assertion

[Kirill Zhukov]

while taking advantage of defined contract

[Shawn]

interesting… I can’t help but wonder if this is a problem with the test or method in question rather than the lack of a given assertion mechanism

[Shawn]

are you checking for a specific implementation of something?

[Shawn]

like the compiler should already verify a return type, unless, I guess, the return type of a given method is T or Any