Add an in-memory implementation of the MessageRepository.

app/src/main/java/chat/rocket/android/server/domain/MessagesRepository.kt

+package chat.rocket.android.server.domain
+
+import chat.rocket.core.model.Message
+
+interface MessagesRepository {
+
+    /**
+     * Get message by its message id.
+     *
+     * @param id The id of the message to get.
+     * @return The Message object given by the id or null if message wasn't found.
+     */
+    fun getById(id: String): Message?
+
+    /**
+     * Get all messages from the current room id.
+     *
+     * @param rid The room id.
+     * @return A list of Message objects for the room with given room id or an empty list.
+     */
+    fun getByRoomId(rid: String): List<Message>
+
+    /**
+     * Get all messages. Use carefully!
+     * @return All messages or an empty list.
+     */
+    fun getAll(): List<Message>
+
+    /**
+     * Save a single message object.
+     *
+     * @param The message object to saveAll.
+     */
+    fun save(message: Message)
+
+    /**
+     * Save a list of messages.
+     */
+    fun saveAll(newMessages: List<Message>)
+
+    /**
+     * Removes all messages.
+     */
+    fun clear()
+
+    /**
+     * Remove message by id.
+     *
+     * @param id The id of the message to remove.
+     */
+    fun removeById(id: String)
+
+    /**
+     * Remove all messages from a given room.
+     *
+     * @param rid The room id where messages are to be removed.
+     */
+    fun removeByRoomId(rid: String)
+}
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app/src/main/java/chat/rocket/android/server/infraestructure/MemoryMessagesRepository.kt

+package chat.rocket.android.server.infraestructure
+
+import chat.rocket.android.server.domain.MessagesRepository
+import chat.rocket.core.model.Message
+
+class MemoryMessagesRepository : MessagesRepository {
+
+    private val messages: HashMap<String, Message> = HashMap()
+
+    override fun getById(id: String): Message? {
+        return messages[id]
+    }
+
+    override fun getByRoomId(rid: String): List<Message> {
+        return messages.filter { it.value.roomId == rid }.values.toList()
+    }
+
+    override fun getAll(): List<Message> = messages.values.toList()
+
+    override fun save(message: Message) {
+        messages[message.id] = message
+    }
+
+    override fun saveAll(newMessages: List<Message>) {
+        for (msg in newMessages) {
+            messages[msg.id] = msg
+        }
+    }
+
+    override fun clear() {
+        messages.clear()
+    }
+
+    override fun removeById(id: String) {
+        messages.remove(id)
+    }
+
+    override fun removeByRoomId(rid: String) {
+        val roomMessages = messages.filter { it.value.roomId == rid }.values
+        roomMessages.forEach {
+            messages.remove(it.roomId)
+        }
+    }
+}
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app/src/test/java/chat/rocket/android/MemoryMessagesRepositoryTest.kt

+package chat.rocket.android
+
+import chat.rocket.android.server.infraestructure.MemoryMessagesRepository
+import chat.rocket.core.model.Message
+import chat.rocket.core.model.MessageType
+import org.hamcrest.CoreMatchers.notNullValue
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.hamcrest.CoreMatchers.`is` as isEqualTo
+
+class MemoryMessagesRepositoryTest {
+
+    val repository = MemoryMessagesRepository()
+
+    val msg = Message(
+            id = "messageId",
+            roomId = "GENERAL",
+            message = "Beam me up, Scotty.",
+            timestamp = 1511443964815,
+            attachments = null,
+            sender = null,
+            avatar = null,
+            channels = null,
+            editedAt = null,
+            editedBy = null,
+            groupable = true,
+            mentions = null,
+            parseUrls = false,
+            senderAlias = null,
+            type = MessageType.MessageRemoved(),
+            updatedAt = 1511443964815,
+            urls = null
+    )
+
+    val msg2 = Message(
+            id = "messageId2",
+            roomId = "sandbox",
+            message = "Highly Illogical",
+            timestamp = 1511443964818,
+            attachments = null,
+            sender = null,
+            avatar = null,
+            channels = null,
+            editedAt = null,
+            editedBy = null,
+            groupable = true,
+            mentions = null,
+            parseUrls = false,
+            senderAlias = null,
+            type = MessageType.MessageRemoved(),
+            updatedAt = 1511443964818,
+            urls = null
+    )
+
+    @Before
+    fun setup() {
+        repository.clear()
+    }
+
+    @Test
+    fun `save() should save a single message`() {
+        assertThat(repository.getAll().size, isEqualTo(0))
+        repository.save(msg)
+        val allMessages = repository.getAll()
+        assertThat(allMessages.size, isEqualTo(1))
+        allMessages[0].apply {
+            assertThat(id, isEqualTo("messageId"))
+            assertThat(message, isEqualTo("Beam me up, Scotty."))
+            assertThat(roomId, isEqualTo("GENERAL"))
+        }
+    }
+
+    @Test
+    fun `saveAll() should all saved messages`() {
+        assertThat(repository.getAll().size, isEqualTo(0))
+        repository.saveAll(listOf(msg, msg2))
+        val allMessages = repository.getAll()
+        assertThat(allMessages.size, isEqualTo(2))
+        allMessages[0].apply {
+            assertThat(id, isEqualTo("messageId"))
+            assertThat(message, isEqualTo("Beam me up, Scotty."))
+            assertThat(roomId, isEqualTo("GENERAL"))
+        }
+
+        allMessages[1].apply {
+            assertThat(id, isEqualTo("messageId2"))
+            assertThat(message, isEqualTo("Highly Illogical"))
+            assertThat(roomId, isEqualTo("sandbox"))
+        }
+    }
+
+    @Test
+    fun `getById() should return a single message`() {
+        repository.saveAll(listOf(msg, msg2))
+        var singleMsg = repository.getById("messageId")
+        assertThat(singleMsg, notNullValue())
+        singleMsg!!.apply {
+            assertThat(id, isEqualTo("messageId"))
+            assertThat(message, isEqualTo("Beam me up, Scotty."))
+            assertThat(roomId, isEqualTo("GENERAL"))
+        }
+
+        singleMsg = repository.getById("messageId2")
+        assertThat(singleMsg, notNullValue())
+        singleMsg!!.apply {
+            assertThat(id, isEqualTo("messageId2"))
+            assertThat(message, isEqualTo("Highly Illogical"))
+            assertThat(roomId, isEqualTo("sandbox"))
+        }
+    }
+
+    @Test
+    fun `getByRoomId() should return all messages for room id or an empty list`() {
+        repository.saveAll(listOf(msg, msg2))
+        var roomMessages = repository.getByRoomId("faAad32fkasods2")
+        assertThat(roomMessages.isEmpty(), isEqualTo(true))
+
+        roomMessages = repository.getByRoomId("sandbox")
+        assertThat(roomMessages.size, isEqualTo(1))
+        roomMessages[0].apply {
+            assertThat(id, isEqualTo("messageId2"))
+            assertThat(message, isEqualTo("Highly Illogical"))
+            assertThat(roomId, isEqualTo("sandbox"))
+        }
+
+        roomMessages = repository.getByRoomId("GENERAL")
+        assertThat(roomMessages.size, isEqualTo(1))
+        roomMessages[0].apply {
+            assertThat(id, isEqualTo("messageId"))
+            assertThat(message, isEqualTo("Beam me up, Scotty."))
+            assertThat(roomId, isEqualTo("GENERAL"))
+        }
+    }
+}
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