Part3: extensions

Author: antonarhipov

build.gradle.kts

@@ -34,6 +34,8 @@ dependencies {
 
 	implementation("org.springframework.boot:spring-boot-starter-data-jdbc")
 	runtimeOnly("com.h2database:h2")
+
+	implementation("org.jetbrains:markdown:0.1.45")
 }
 
 tasks.withType<Test> {

src/main/kotlin/com/example/kotlin/chat/Extensions.kt

@@ -0,0 +1,36 @@
+package com.example.kotlin.chat
+
+import com.example.kotlin.chat.repository.ContentType
+import com.example.kotlin.chat.repository.Message
+import com.example.kotlin.chat.service.MessageVM
+import com.example.kotlin.chat.service.UserVM
+import org.intellij.markdown.flavours.commonmark.CommonMarkFlavourDescriptor
+import org.intellij.markdown.html.HtmlGenerator
+import org.intellij.markdown.parser.MarkdownParser
+import java.net.URL
+
+fun MessageVM.asDomainObject(contentType: ContentType = ContentType.MARKDOWN): Message = Message(
+    content,
+    contentType,
+    sent,
+    user.name,
+    user.avatarImageLink.toString(),
+    id
+)
+
+fun Message.asViewModel(): MessageVM = MessageVM(
+    contentType.render(content),
+    UserVM(username, URL(userAvatarImageLink)),
+    sent,
+    id
+)
+
+fun List<Message>.mapToViewModel(): List<MessageVM> = map { it.asViewModel() }
+
+fun ContentType.render(content: String): String = when (this) {
+    ContentType.PLAIN -> content
+    ContentType.MARKDOWN -> {
+        val flavour = CommonMarkFlavourDescriptor()
+        HtmlGenerator(content, MarkdownParser(flavour).buildMarkdownTreeFromString(content), flavour).generateHtml()
+    }
+}

src/main/kotlin/com/example/kotlin/chat/repository/DomainModel.kt

@@ -14,5 +14,5 @@ data class Message(
     @Id var id: String? = null)
 
 enum class ContentType {
-    PLAIN
+    PLAIN, MARKDOWN
 }

src/main/kotlin/com/example/kotlin/chat/service/PersistentMessageService.kt

@@ -1,27 +1,24 @@
 package com.example.kotlin.chat.service
 
-import com.example.kotlin.chat.repository.ContentType
-import com.example.kotlin.chat.repository.Message
+import com.example.kotlin.chat.asDomainObject
+import com.example.kotlin.chat.mapToViewModel
 import com.example.kotlin.chat.repository.MessageRepository
 import org.springframework.context.annotation.Primary
 import org.springframework.stereotype.Service
-import java.net.URL
 
 @Service
 @Primary
 class PersistentMessageService(val messageRepository: MessageRepository) : MessageService {
 
     override fun latest(): List<MessageVM> =
-            messageRepository.findLatest()
-                    .map { with(it) { MessageVM(content, UserVM(username, URL(userAvatarImageLink)), sent, id) } }
+        messageRepository.findLatest()
+            .mapToViewModel()
 
     override fun after(messageId: String): List<MessageVM> =
-            messageRepository.findLatest(messageId)
-                    .map { with(it) { MessageVM(content, UserVM(username, URL(userAvatarImageLink)), sent, id) } }
+        messageRepository.findLatest(messageId)
+            .mapToViewModel()
 
     override fun post(message: MessageVM) {
-        messageRepository.save(
-                with(message) { Message(content, ContentType.PLAIN, sent, user.name, user.avatarImageLink.toString()) }
-        )
+        messageRepository.save(message.asDomainObject())
     }
 }

src/test/kotlin/com/example/kotlin/chat/ChatKotlinApplicationTests.kt

@@ -56,14 +56,14 @@ class ChatKotlinApplicationTests {
                 ),
                 Message(
                     "**testMessage2**",
-                    ContentType.PLAIN,
+                    ContentType.MARKDOWN,
                     secondBeforeNow,
                     "test1",
                     "http://test.com"
                 ),
                 Message(
                     "`testMessage3`",
-                    ContentType.PLAIN,
+                    ContentType.MARKDOWN,
                     now,
                     "test2",
                     "http://test.com"
@@ -100,15 +100,15 @@ class ChatKotlinApplicationTests {
                 )
         }
 
-        assertThat(messages?.map { with(it) { copy(id = null, sent = sent.truncatedTo(MILLIS)) } })
+        assertThat(messages?.map { it.prepareForTesting() })
             .containsSubsequence(
                 MessageVM(
-                    "**testMessage2**",
+                    "<body><p><strong>testMessage2</strong></p></body>",
                     UserVM("test1", URL("http://test.com")),
                     now.minusSeconds(1).truncatedTo(MILLIS)
                 ),
                 MessageVM(
-                    "`testMessage3`",
+                    "<body><p><code>testMessage3</code></p></body>",
                     UserVM("test2", URL("http://test.com")),
                     now.truncatedTo(MILLIS)
                 )
@@ -127,17 +127,17 @@ class ChatKotlinApplicationTests {
 			)
 		)
 
-		messageRepository.findAll()
-			.first { it.content.contains("HelloWorld") }
-			.apply {
-				assertThat(this.copy(id = null, sent = sent.truncatedTo(MILLIS)))
-					.isEqualTo(Message(
-						"`HelloWorld`",
-						ContentType.PLAIN,
-						now.plusSeconds(1).truncatedTo(MILLIS),
-						"test",
-						"http://test.com"
-					))
-			}
+        messageRepository.findAll()
+            .first { it.content.contains("HelloWorld") }
+            .apply {
+                assertThat(this.prepareForTesting())
+                    .isEqualTo(Message(
+                        "`HelloWorld`",
+                        ContentType.MARKDOWN,
+                        now.plusSeconds(1).truncatedTo(MILLIS),
+                        "test",
+                        "http://test.com"
+                    ))
+            }
 	}
 }

src/test/kotlin/com/example/kotlin/chat/TestExtensions.kt

@@ -0,0 +1,9 @@
+package com.example.kotlin.chat
+
+import com.example.kotlin.chat.repository.Message
+import com.example.kotlin.chat.service.MessageVM
+import java.time.temporal.ChronoUnit.MILLIS
+
+fun MessageVM.prepareForTesting() = copy(id = null, sent = sent.truncatedTo(MILLIS))
+
+fun Message.prepareForTesting() = copy(id = null, sent = sent.truncatedTo(MILLIS))