feat: make message hash compatible with decoded message

packages/message-hash/src/index.spec.ts

@@ -1,4 +1,4 @@
-import type { IProtoMessage } from "@waku/interfaces";
+import type { IDecodedMessage, IProtoMessage } from "@waku/interfaces";
 import { bytesToHex, hexToBytes } from "@waku/utils/bytes";
 import { expect } from "chai";
 
@@ -75,4 +75,38 @@ describe("RFC Test Vectors", () => {
     const hash = messageHash(pubsubTopic, message);
     expect(bytesToHex(hash)).to.equal(expectedHash);
   });
+
+  it("Waku message hash computation (no timestamp)", () => {
+    const expectedHash =
+      "e1a9596237dbe2cc8aaf4b838c46a7052df6bc0d42ba214b998a8bfdbe8487d6";
+    const pubsubTopic = "/waku/2/default-waku/proto";
+    const message: IProtoMessage = {
+      payload: new Uint8Array(),
+      contentTopic: "/waku/2/default-content/proto",
+      meta: hexToBytes("0x73757065722d736563726574"),
+      timestamp: undefined,
+      ephemeral: undefined,
+      rateLimitProof: undefined,
+      version: undefined
+    };
+    const hash = messageHash(pubsubTopic, message);
+    expect(bytesToHex(hash)).to.equal(expectedHash);
+  });
+
+  it("Waku message hash computation (message is IDecodedMessage)", () => {
+    const expectedHash =
+      "bd81b27902ad51f49e8f73ff8db4a96994040c9421da88b7ee8ba07bd39070b2";
+    const pubsubTopic = "/waku/2/default-waku/proto";
+    const message: IDecodedMessage = {
+      payload: new Uint8Array(),
+      pubsubTopic,
+      contentTopic: "/waku/2/default-content/proto",
+      meta: hexToBytes("0x73757065722d736563726574"),
+      timestamp: new Date("2024-04-30T10:54:14.978Z"),
+      ephemeral: undefined,
+      rateLimitProof: undefined
+    };
+    const hash = messageHash(pubsubTopic, message);
+    expect(bytesToHex(hash)).to.equal(expectedHash);
+  });
 });

packages/message-hash/src/index.ts

@@ -1,5 +1,5 @@
 import { sha256 } from "@noble/hashes/sha256";
-import type { IProtoMessage } from "@waku/interfaces";
+import type { IDecodedMessage, IProtoMessage } from "@waku/interfaces";
 import { isDefined } from "@waku/utils";
 import {
   bytesToUtf8,
@@ -14,13 +14,11 @@ import {
  */
 export function messageHash(
   pubsubTopic: string,
-  message: IProtoMessage
+  message: IProtoMessage | IDecodedMessage
 ): Uint8Array {
   const pubsubTopicBytes = utf8ToBytes(pubsubTopic);
   const contentTopicBytes = utf8ToBytes(message.contentTopic);
-  const timestampBytes = message.timestamp
-    ? numberToBytes(message.timestamp)
-    : undefined;
+  const timestampBytes = tryConvertTimestampToBytes(message.timestamp);
 
   const bytes = concat(
     [
@@ -35,9 +33,19 @@ export function messageHash(
   return sha256(bytes);
 }
 
+function tryConvertTimestampToBytes(
+  timestamp: Date | number | bigint | undefined
+): undefined | Uint8Array {
+  if (!timestamp) {
+    return;
+  }
+
+  return numberToBytes(timestamp.valueOf());
+}
+
 export function messageHashStr(
   pubsubTopic: string,
-  message: IProtoMessage
+  message: IProtoMessage | IDecodedMessage
 ): string {
   const hash = messageHash(pubsubTopic, message);
   const hashStr = bytesToUtf8(hash);