In Junit based testing framework there are few possible test outcomes: passed, failed and crashed. In this short note we will dive into that mechanisms.

Test will pass, if no exception is thrown. Empty test should always pass:

class TestFlowShowcase : StringSpec({
    "it should pass"{
        // nothing here
    }
})

Or test with assertion that passes:

class TestFlowShowcase : StringSpec({
    "1 == 1"{
        (1 == 1) shouldBe true
    }
})

Test will fail, if AssertionException (or descendant) would be thrown:

class TestFlowShowcase : StringSpec({
   "it should fail"{
        throw AssertionError("fail")
    }
})

Test will crash, if other exception would be thrown:

class TestFlowShowcase : StringSpec({
    "it should crash"{
        throw Exception("it crashed")
    }
})

How to treat different test outcomes?

Passed	No error was thrown
Failed	AssertionError was thrown in test
Crashed	Other exception was thrown

“Green” test means only that no error was thrown during test execution – it may also mean that no assertion was performed.

Usually test failed means that something is wrong with system under test – it doesn’t meet expectations defined in assertions.

Test crash indicate that something is wrong with test itself – it does not handle exception thrown in system under test, or its mocks are misconfigured.

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