Pass proto in constructor

Makes the relation between the protobuf class and the wrapper more
direct. Conversion only happens at creates or on getters.

examples/cli-chat/src/chat.spec.ts

@@ -6,7 +6,11 @@ import { formatMessage } from './chat';
 describe('CLI Chat app', () => {
   it('Format message', () => {
     const date = new Date(234325324);
-    const chatMessage = new ChatMessage(date, 'alice', 'Hello world!');
+    const chatMessage = ChatMessage.fromUtf8String(
+      date,
+      'alice',
+      'Hello world!'
+    );
 
     expect(formatMessage(chatMessage)).to.match(/^<.*> alice: Hello world!$/);
   });

examples/cli-chat/src/chat.ts

@@ -84,7 +84,7 @@ export default async function startChat(): Promise<void> {
   rl.prompt();
   for await (const line of rl) {
     rl.prompt();
-    const chatMessage = new ChatMessage(new Date(), nick, line);
+    const chatMessage = ChatMessage.fromUtf8String(new Date(), nick, line);
 
     const msg = WakuMessage.fromBytes(chatMessage.encode(), ChatContentTopic);
     await waku.relay.send(msg);
@@ -129,5 +129,5 @@ export function formatMessage(chatMsg: ChatMessage): string {
     minute: '2-digit',
     hour12: false,
   });
-  return `<${timestamp}> ${chatMsg.nick}: ${chatMsg.message}`;
+  return `<${timestamp}> ${chatMsg.nick}: ${chatMsg.payloadAsUtf8}`;
 }

src/lib/chat_message/index.spec.ts

@@ -11,14 +11,14 @@ describe('Chat Message', function () {
         fc.string(),
         fc.string(),
         (timestamp, nick, message) => {
-          const msg = new ChatMessage(timestamp, nick, message);
+          const msg = ChatMessage.fromUtf8String(timestamp, nick, message);
           const buf = msg.encode();
           const actual = ChatMessage.decode(buf);
 
           // Date.toString does not include ms, as we loose this precision by design
           expect(actual.timestamp.toString()).to.eq(timestamp.toString());
           expect(actual.nick).to.eq(nick);
-          expect(actual.message).to.eq(message);
+          expect(actual.payloadAsUtf8).to.eq(message);
         }
       )
     );

src/lib/chat_message/index.ts

@@ -4,33 +4,52 @@ import * as proto from '../../proto/chat/v2/chat_message';
 
 // TODO: Move to waku library?
 export class ChatMessage {
-  public constructor(
-    public timestamp: Date,
-    public nick: string,
-    public message: string
-  ) {}
+  public constructor(public proto: proto.ChatMessage) {}
+
+  /**
+   * Create Chat Message with a utf-8 string as payload.
+   */
+  static fromUtf8String(
+    timestamp: Date,
+    nick: string,
+    text: string
+  ): ChatMessage {
+    const timestampNumber = Math.floor(timestamp.valueOf() / 1000);
+    const payload = Buffer.from(text, 'utf-8');
+
+    return new ChatMessage({
+      timestamp: timestampNumber,
+      nick,
+      payload,
+    });
+  }
 
   static decode(bytes: Uint8Array): ChatMessage {
     const protoMsg = proto.ChatMessage.decode(Reader.create(bytes));
-    const timestamp = new Date(protoMsg.timestamp * 1000);
-    const message = protoMsg.payload
-      ? Array.from(protoMsg.payload)
-          .map((char) => {
-            return String.fromCharCode(char);
-          })
-          .join('')
-      : '';
-    return new ChatMessage(timestamp, protoMsg.nick, message);
+    return new ChatMessage(protoMsg);
   }
 
   encode(): Uint8Array {
-    const timestamp = Math.floor(this.timestamp.valueOf() / 1000);
-    const payload = Buffer.from(this.message, 'utf-8');
+    return proto.ChatMessage.encode(this.proto).finish();
+  }
 
-    return proto.ChatMessage.encode({
-      timestamp,
-      nick: this.nick,
-      payload,
-    }).finish();
+  get timestamp(): Date {
+    return new Date(this.proto.timestamp * 1000);
+  }
+
+  get nick(): string {
+    return this.proto.nick;
+  }
+
+  get payloadAsUtf8(): string {
+    if (!this.proto.payload) {
+      return '';
+    }
+
+    return Array.from(this.proto.payload)
+      .map((char) => {
+        return String.fromCharCode(char);
+      })
+      .join('');
   }
 }