mirokolodii

Class Test(val someInt: Int)
val test1: Test           // warning: no default value, should be initialized 
                          // with non-null value before first use
val test2: Test = null    // error: non-nullable type can't hold null value
val test3: Test? = null   // valid

mirokolodii

val someStr1: String? = null // valid statement, notice a question mark after 'String'
val someStr2: String? // warning: no default value assigned. Should be initialized 
                      // with some (nullable or non-nullable) value before its first use

mirokolodii

val someStr1: String = ""     // same as in Java, i.e initialized with empty string
val someStr2: String          // warning: no default value assigned. Should be initialized 
                              // with a non-null value before its first use
val someStr3: String = null   // error: can't be null

mirokolodii

String someStr1 = "";   // initialized with empty string
String someStr2;        // by default value of someStr2 is null

mirokolodii

@Test
    public void FilterClickShouldChangeRecyclerViewCount() {
        // Get items count before action
        RecyclerView recyclerView = mActivityTestRule.getActivity().findViewById(R.id.recycler_view);
        int countBefore = Objects.requireNonNull(recyclerView.getAdapter()).getItemCount();
        Log.e("count", "Items count before: " + countBefore);

        // Perform action
        ViewInteraction actionMenuItemView = onView(
                allOf(