Test expected exceptions in Kotlin

Question

In Java, the programmer can specify expected exceptions for JUnit test cases like this:

@Test(expected = ArithmeticException.class)
public void omg()
{
    int bl         


        

Answer 1

Assert extension that verifies the exception class and also if the error message match.

inline fun  assertThrows(runnable: () -> Any?, message: String?) {
try {
    runnable.invoke()
} catch (e: Throwable) {
    if (e is T) {
        message?.let {
            Assert.assertEquals(it, "${e.message}")
        }
        return
    }
    Assert.fail("expected ${T::class.qualifiedName} but caught " +
            "${e::class.qualifiedName} instead")
}
Assert.fail("expected ${T::class.qualifiedName}")

}

for example:

assertThrows({
        throw IllegalStateException("fake error message")
    }, "fake error message")