Show app toasts on the projected car display

gearslip/src/test/java/app/seb3thehacker/gearslip/car/CarToastsTest.kt

@@ -0,0 +1,80 @@
+package app.seb3thehacker.gearslip.car
+
+import androidx.car.app.CarToast
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotSame
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertSame
+import org.junit.Before
+import org.junit.Test
+
+class CarToastsTest {
+    @Before
+    @After
+    fun clearToast() {
+        CarToasts.message.value?.let(CarToasts::dismiss)
+    }
+
+    @Test
+    fun expiredToastCannotDismissItsReplacement() {
+        val owner = Any()
+        CarToasts.show(owner, "First", CarToast.LENGTH_SHORT)
+        val first = requireNotNull(CarToasts.message.value)
+        CarToasts.show(owner, "Second", CarToast.LENGTH_LONG)
+        val second = requireNotNull(CarToasts.message.value)
+
+        CarToasts.dismiss(first)
+        assertSame(second, CarToasts.message.value)
+        CarToasts.dismiss(second)
+        assertNull(CarToasts.message.value)
+    }
+
+    @Test
+    fun identicalMessagesStillRestartTheDisplayTimer() {
+        val owner = Any()
+        CarToasts.show(owner, "Saved", CarToast.LENGTH_SHORT)
+        val first = requireNotNull(CarToasts.message.value)
+        CarToasts.show(owner, "Saved", CarToast.LENGTH_SHORT)
+        val repeated = requireNotNull(CarToasts.message.value)
+
+        assertNotSame(first, repeated)
+        CarToasts.dismiss(first)
+        assertSame(repeated, CarToasts.message.value)
+    }
+
+    @Test
+    fun disconnectOnlyClearsItsOwnToast() {
+        val nav = Any()
+        val browse = Any()
+        CarToasts.show(nav, "Route saved", CarToast.LENGTH_SHORT)
+        CarToasts.show(browse, "Added to playlist", CarToast.LENGTH_SHORT)
+        val latest = CarToasts.message.value
+
+        CarToasts.clear(nav)
+        assertSame(latest, CarToasts.message.value)
+        CarToasts.clear(browse)
+        assertNull(CarToasts.message.value)
+    }
+
+    @Test
+    fun blankRequestsDoNotReplaceAVisibleMessage() {
+        val owner = Any()
+        CarToasts.show(owner, "Saved", CarToast.LENGTH_SHORT)
+        val visible = CarToasts.message.value
+
+        CarToasts.show(owner, " \n\t", CarToast.LENGTH_LONG)
+        assertSame(visible, CarToasts.message.value)
+    }
+
+    @Test
+    fun unknownDurationsFallBackToShortRatherThanStayingVisible() {
+        val owner = Any()
+        CarToasts.show(owner, "Short", CarToast.LENGTH_SHORT)
+        assertEquals(2_000L, CarToasts.message.value?.durationMs)
+        CarToasts.show(owner, "Long", CarToast.LENGTH_LONG)
+        assertEquals(3_500L, CarToasts.message.value?.durationMs)
+        CarToasts.show(owner, "Unknown", Int.MAX_VALUE)
+        assertEquals(2_000L, CarToasts.message.value?.durationMs)
+    }
+}