feat(tests): unit test for cardinal detection

app/src/main/java/dev/synapsetech/compass/MainActivity.kt

@@ -29,8 +29,7 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.launch
 
-
-private enum class Cardinal(val letter: String, val degree: Int) {
+enum class Cardinal(val letter: String, val degree: Int) {
     NORTH("N", 0),
     EAST("E", 90),
     SOUTH("S", 180),

app/src/test/java/dev/synapsetech/compass/CardinalEnumTest.kt

@@ -0,0 +1,27 @@
+package dev.synapsetech.compass
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+class CardinalEnumTest {
+    @Test
+    fun detection_isCorrect() {
+        assertEquals(Cardinal.NORTH, Cardinal.fromDegree(0))
+        assertEquals(Cardinal.NORTH, Cardinal.fromDegree(360))
+        assertEquals(Cardinal.NORTH, Cardinal.fromDegree(10))
+        assertEquals(Cardinal.NORTH, Cardinal.fromDegree(350))
+
+        assertEquals(Cardinal.EAST, Cardinal.fromDegree(90))
+        assertEquals(Cardinal.EAST, Cardinal.fromDegree(83))
+        assertEquals(Cardinal.EAST, Cardinal.fromDegree(99))
+
+        assertEquals(Cardinal.SOUTH, Cardinal.fromDegree(180))
+        assertEquals(Cardinal.SOUTH, Cardinal.fromDegree(172))
+        assertEquals(Cardinal.SOUTH, Cardinal.fromDegree(194))
+
+        assertEquals(Cardinal.WEST, Cardinal.fromDegree(270))
+        assertEquals(Cardinal.WEST, Cardinal.fromDegree(267))
+        assertEquals(Cardinal.WEST, Cardinal.fromDegree(286))
+    }
+}