Hi everyone, I have a really weird bug and I have ...

# mockk

[Gil Goldzweig]

Hi everyone, I have a really weird bug and I have no idea why.
I'm trying to unit test changing android night theme so I'm using
mockkStatic to mock AppCompatDelegate and it works well.

I use the same function to test all 3 themes

private fun testTheme(themeMode: Int, radioButtonId: Int) {
    System.out.println("Testing theme: $themeMode")
    selectedTheme = slot()
    every {
        setDefaultNightMode(capture(selectedTheme))
    } answers {
        System.out.println("Setting theme: ${selectedTheme.captured}")
    }

    onView(withId(radioButtonId)).perform(ViewActions.click())

    assertEquals(themeMode, selectedTheme.captured, "Selected theme")
    assertEquals(themeMode, selectedMode, "SharedPreferences")
}

public static final int MODE_NIGHT_FOLLOW_SYSTEM = -1;

public static final int MODE_NIGHT_NO = 1;

public static final int MODE_NIGHT_YES = 2;

The RadioButton is just to select the right theme and call the check.

These are the test cases

@Test
fun `test clicking on light radio button applies light theme`() {
    initialize {
        testTheme(MODE_NIGHT_NO, R.id.fragment_theme_selection_radio_button_light)
    }
}

@Test
fun `test clicking on dark radio button applies dark theme`() {
    initialize {
        testTheme(MODE_NIGHT_YES, R.id.fragment_theme_selection_radio_button_dark)
    }
}

@Test
fun `test clicking on follow system radio button applies system theme`() {
    initialize {
        testTheme(MODE_NIGHT_FOLLOW_SYSTEM, R.id.fragment_theme_selection_radio_button_system)
    }
}

The function works for NIGHT_NO and NIGHT_YES but not in FOLLOW_SYSTEM
It's not that I'm getting wrong values is that I received an exception

lateinit property captured has not been initialized
kotlin.UninitializedPropertyAccessException: lateinit property captured has not been initialized
	at io.mockk.CapturingSlot.getCaptured(API.kt:2503)

But if I'll add any of the other tests first, it works

@Test
fun `test clicking on follow system radio button applies system theme`() {
    initialize {
        testTheme(MODE_NIGHT_YES, R.id.fragment_theme_selection_radio_button_dark)
        testTheme(MODE_NIGHT_FOLLOW_SYSTEM, R.id.fragment_theme_selection_radio_button_system)
    }
}

Now, I tried to debug it, I'm unable to even capture it

[Mattia Tommasone]

what if you call testTheme outside of initialize blocks?

[Gil Goldzweig]

I can't I need it to setup the fragment code