JUnit tests always pass when executing in device

Issue

This simple test

@RunWith(JUnit4::class)
class Test {

    @Test
    fun test() {
        assert(false)
    }

}

Unexpectedly, this passes when put in androidTest (both through Android Studio and in the terminal), but obviously fails as expected when put in test.

Solution

You need to use JUnit assertions for running tests. The base assert() functionality is normally disabled when running "production" code, so you cannot depend that a plain assert statement will throw an assertion exception.

Use:

org.junit.Asserts.assertTrue( false )

to make the test fail properly.

Answered By - Bob Dalgleish