ViewModelTest.kt

class ViewModelTest {
    @get:Rule
    val mainCoroutineRule = MainCoroutineRule()

    private val viewModel by lazy {
        CalculatorViewModel(SavedStateHandle(mutableMapOf()))
    }

    @Test
    fun `sets the result when an input changes`() {
        viewModel.v1 = "10"
        viewModel.v2 = "20"
        assertThat(viewModel.result).isEqualTo("30")
    }
}