Add converter function for ChatMessage entity to domain entity.

Signed-off-by: Yahor Berdnikau <egorr.berd@gmail.com>

ultrasonic/src/main/kotlin/org/moire/ultrasonic/data/APIChatMessageConverter.kt

@@ -0,0 +1,15 @@
+// Contains helper functions to convert from api ChatMessage entity to domain entity
+@file:JvmName("APIChatMessageConverter")
+package org.moire.ultrasonic.data
+
+import org.moire.ultrasonic.domain.ChatMessage
+import org.moire.ultrasonic.api.subsonic.models.ChatMessage as ApiChatMessage
+
+fun ApiChatMessage.toDomainEntity(): ChatMessage = ChatMessage().apply {
+    username = this@toDomainEntity.username
+    time = this@toDomainEntity.time
+    message = this@toDomainEntity.message
+}
+
+fun List<ApiChatMessage>.toDomainEntitiesList(): List<ChatMessage> = this
+        .map { it.toDomainEntity() }

ultrasonic/src/test/kotlin/org/moire/ultrasonic/data/APIChatMessageConverterTest.kt

@@ -0,0 +1,40 @@
+@file:Suppress("IllegalIdentifier")
+
+package org.moire.ultrasonic.data
+
+import org.amshove.kluent.`should equal to`
+import org.amshove.kluent.`should equal`
+import org.junit.Test
+import org.moire.ultrasonic.api.subsonic.models.ChatMessage
+
+/**
+ * Unit test for functions converting api [ChatMessage] to domain entity.
+ */
+class APIChatMessageConverterTest {
+    @Test
+    fun `Should convert entity`() {
+        val entity = ChatMessage("Woohoo", 553434L, "Wow")
+
+        val domainEntity = entity.toDomainEntity()
+
+        with(domainEntity) {
+            username `should equal to` entity.username
+            time `should equal to` entity.time
+            message `should equal to` entity.message
+        }
+    }
+
+    @Test
+    fun `Should convert list of entities`() {
+        val entitiesList = listOf(ChatMessage("AAA"), ChatMessage("BBB"))
+
+        val domainEntitiesList = entitiesList.toDomainEntitiesList()
+
+        with(domainEntitiesList) {
+            size `should equal to` entitiesList.size
+            forEachIndexed { index, chatMessage ->
+                chatMessage `should equal` entitiesList[index].toDomainEntity()
+            }
+        }
+    }
+}