From 43ecd31e768753c2854b63a68ab7200ce9577ba5 Mon Sep 17 00:00:00 2001
From: Franck Royer <franck@royer.one>
Date: Wed, 6 Oct 2021 12:52:41 +1100
Subject: [PATCH] Generation of content topic is the same for chats and
 communities

---
 packages/status-communities/src/chat.ts         | 4 ++--
 packages/status-communities/src/contentTopic.ts | 9 +++++++--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/packages/status-communities/src/chat.ts b/packages/status-communities/src/chat.ts
index 184d50dd..95457c87 100644
--- a/packages/status-communities/src/chat.ts
+++ b/packages/status-communities/src/chat.ts
@@ -1,4 +1,4 @@
-import { chatIdToContentTopic } from "./contentTopic";
+import { idToContentTopic } from "./contentTopic";
 import { createSymKeyFromPassword } from "./encryption";
 import { ChatMessage, Content } from "./wire/chat_message";
 
@@ -21,7 +21,7 @@ export class Chat {
   }
 
   public get contentTopic(): string {
-    return chatIdToContentTopic(this.id);
+    return idToContentTopic(this.id);
   }
 
   public createMessage(content: Content): ChatMessage {
diff --git a/packages/status-communities/src/contentTopic.ts b/packages/status-communities/src/contentTopic.ts
index 07bba7b2..0c78777f 100644
--- a/packages/status-communities/src/contentTopic.ts
+++ b/packages/status-communities/src/contentTopic.ts
@@ -4,8 +4,13 @@ import { keccak256 } from "js-sha3";
 
 const TopicLength = 4;
 
-export function chatIdToContentTopic(chatId: string): string {
-  const hash = keccak256.arrayBuffer(chatId);
+/**
+ * Get the content topic of for a given Chat or Community
+ * @param id The Chat id or Community id (hex string prefixed with 0x).
+ * @returns string The Waku v2 Content Topic.
+ */
+export function idToContentTopic(id: string): string {
+  const hash = keccak256.arrayBuffer(id);
 
   const topic = Buffer.from(hash).slice(0, TopicLength);