add unit test for Storage

app/core/src/test/java/com/fsck/k9/preferences/StorageTest.kt

@@ -0,0 +1,79 @@
+package com.fsck.k9.preferences
+
+
+import org.junit.Assert.*
+import org.junit.Test
+
+
+private const val TEST_STRING_KEY = "s"
+private const val TEST_STRING_VALUE = "y"
+private const val TEST_INT_KEY = "i"
+private const val TEST_INT_VALUE = "4"
+private const val TEST_STRING_DEFAULT = "z"
+private const val TEST_INT_DEFAULT = 2
+private val TEST_MAP = mapOf(
+        TEST_STRING_KEY to TEST_STRING_VALUE,
+        TEST_INT_KEY to TEST_INT_VALUE
+)
+
+class StorageTest {
+    internal var storage = Storage()
+
+    @Test
+    fun isEmpty() {
+        assertTrue(storage.isEmpty)
+    }
+
+    @Test
+    fun isNotEmpty() {
+        storage.replaceAll(TEST_MAP)
+        assertFalse(storage.isEmpty)
+    }
+
+    @Test
+    fun contains() {
+        storage.replaceAll(TEST_MAP)
+        assertTrue(storage.contains(TEST_STRING_KEY))
+    }
+
+    @Test
+    fun getString() {
+        storage.replaceAll(TEST_MAP)
+        assertEquals(TEST_STRING_VALUE, storage.getString(TEST_STRING_KEY, TEST_STRING_DEFAULT))
+    }
+
+    @Test
+    fun getString_default() {
+        assertTrue(storage.isEmpty)
+        assertEquals(TEST_STRING_DEFAULT, storage.getString(TEST_STRING_KEY, TEST_STRING_DEFAULT))
+    }
+
+    @Test
+    fun getAll() {
+        storage.replaceAll(TEST_MAP)
+        assertFalse(storage.isEmpty)
+        assertEquals(TEST_MAP, storage.all)
+    }
+
+    @Test
+    fun replaceAll() {
+        storage.replaceAll(TEST_MAP)
+        storage.replaceAll(emptyMap())
+        assertTrue(storage.isEmpty)
+    }
+
+    @Test
+    fun getInteger() {
+        storage.replaceAll(TEST_MAP)
+
+        assertEquals(Integer.parseInt(TEST_INT_VALUE), storage.getInt(TEST_INT_KEY, TEST_INT_DEFAULT))
+    }
+
+    @Test
+    fun getInteger_stringValue() {
+        storage.replaceAll(TEST_MAP)
+
+        // TODO is this good behavior?
+        assertEquals(TEST_INT_DEFAULT, storage.getInt(TEST_STRING_KEY, TEST_INT_DEFAULT))
+    }
+}