SpyExample.kt

@Test
fun `Track analytics event when creating new note`() {
    val analyticsWrapperSpy = //Spy
    val noteAnalytics = NoteAnalytics(analyticsWrapperSpy) //System under test

    //AnalyticsWrapperSpy records the interaction with NoteAnalytics under the hoods
    noteAnalytics.trackCreateNewNoteEvent(NoteType.Supermarket)

    //Based on the its internal implementation, the spy returns the state of the dependency
    val numberOfEvents = analyticsWrapperSpy.getNewNoteEventsRegistered()
    assertEquals(expected = 1, actual = numberOfEvents)
}