From 3f7d29955901ef470f16b0a404e95f9b232ff9e6 Mon Sep 17 00:00:00 2001
From: Andre Staltz <andre@staltz.com>
Date: Mon, 17 Apr 2023 21:49:17 +0300
Subject: [PATCH] msg hash is only applied on msg.metadata

---
 lib/feed-v1/get-msg-id.js   |  6 ++----
 lib/feed-v1/index.js        | 22 +++++++++++++++++++++-
 test/erase.test.js          |  5 ++---
 test/feed-v1-create.test.js |  9 +++++----
 4 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/lib/feed-v1/get-msg-id.js b/lib/feed-v1/get-msg-id.js
index 773ab0c..5a05c74 100644
--- a/lib/feed-v1/get-msg-id.js
+++ b/lib/feed-v1/get-msg-id.js
@@ -11,10 +11,8 @@ const stringify = require('fast-json-stable-stringify')
  * @returns {Buffer}
  */
 function getMsgHashBuf(msg) {
-  const { metadata, sig } = msg
-  const metadataBuf = Buffer.from(stringify(metadata), 'utf8')
-  const sigBuf = base58.decode(sig)
-  return blake3.hash(Buffer.concat([metadataBuf, sigBuf])).subarray(0, 16)
+  const metadataBuf = Buffer.from(stringify(msg.metadata), 'utf8')
+  return blake3.hash(metadataBuf).subarray(0, 16)
 }
 
 /**
diff --git a/lib/feed-v1/index.js b/lib/feed-v1/index.js
index 46928ec..447f680 100644
--- a/lib/feed-v1/index.js
+++ b/lib/feed-v1/index.js
@@ -103,6 +103,25 @@ function isFeedRoot(msg, authorId, findType) {
   return who === findWho && type === findType && isEmptyObject(tangles)
 }
 
+function getFeedRootHash(authorId, type) {
+  const who = stripAuthor(authorId)
+
+  const msg = {
+    content: null,
+    metadata: {
+      hash: null,
+      size: 0,
+      tangles: {},
+      type,
+      v: 1,
+      who,
+    },
+    sig: '',
+  }
+
+  return getMsgHash(msg)
+}
+
 function toPlaintextBuffer(opts) {
   return Buffer.from(stringify(opts.content), 'utf8')
 }
@@ -195,7 +214,7 @@ function createRoot(keys, type) {
  * @returns {Msg}
  */
 function erase(msg) {
-  return {...msg, content: null}
+  return { ...msg, content: null }
 }
 
 /**
@@ -211,6 +230,7 @@ module.exports = {
   getMsgHash,
   getMsgId,
   isFeedRoot,
+  getFeedRootHash,
   // getFeedId,
   // isFeedId,
   // isMsg,
diff --git a/test/erase.test.js b/test/erase.test.js
index e721a7f..3a42a60 100644
--- a/test/erase.test.js
+++ b/test/erase.test.js
@@ -20,7 +20,6 @@ test('erase', async (t) => {
 
   await peer.db.loaded()
 
-  const rootHash = 'Nf2kuXAYsLBHEgU9eonYdn'
   const msgHashes = []
   for (let i = 0; i < 5; i++) {
     const rec = await p(peer.db.create)({
@@ -48,8 +47,8 @@ test('erase', async (t) => {
 
   const after2 = []
   for (const msg of peer.db.msgs()) {
-    if (msg.metadata.tangles[rootHash]) {
-      after2.push(msg.metadata.tangles[rootHash].depth)
+    for (const tangleId in msg.metadata.tangles) {
+      after2.push(msg.metadata.tangles[tangleId].depth)
     }
   }
 
diff --git a/test/feed-v1-create.test.js b/test/feed-v1-create.test.js
index 3b87768..1a74bce 100644
--- a/test/feed-v1-create.test.js
+++ b/test/feed-v1-create.test.js
@@ -14,8 +14,9 @@ tape('FeedV1.createRoot()', (t) => {
   t.equals(rootMsg.metadata.who, FeedV1.stripAuthor(keys.id), 'who')
   t.deepEquals(rootMsg.metadata.tangles, {}, 'tangles')
 
+  console.log(rootMsg);
   rootHash = FeedV1.getMsgHash(rootMsg)
-  t.equals(rootHash, 'Nf2kuXAYsLBHEgU9eonYdn', 'root hash')
+  t.equals(rootHash, '3F26EgnwbMHm1EEeeVM1Eb', 'root hash')
   t.end()
 })
 
@@ -54,7 +55,7 @@ tape('FeedV1.create()', (t) => {
 
   console.log(msg1)
 
-  const msgHash1 = 'SktCiaHrUxz2mXS1SRSDmj'
+  const msgHash1 = 'MTYQM89hvHuiVKaw8Ze7kc'
 
   t.equals(
     FeedV1.getMsgId(msg1),
@@ -99,7 +100,7 @@ tape('FeedV1.create()', (t) => {
 
   t.deepEqual(
     FeedV1.getMsgId(msg2),
-    'ppppp:message/v1/4mjQ5aJu378cEu6TksRG3uXAiKFiwGjYQtWAjfVjDAJW/post/Nej4ibHrxryTduWqDeCJE4',
+    'ppppp:message/v1/4mjQ5aJu378cEu6TksRG3uXAiKFiwGjYQtWAjfVjDAJW/post/T7juKvDH2bqEUhJB9Dxctr',
     'getMsgId'
   )
 
@@ -122,7 +123,7 @@ tape('create() handles DAG tips correctly', (t) => {
   const msgHash1 = FeedV1.getMsgHash(msg1)
   t.deepEquals(
     msg1.metadata.tangles[rootHash].prev,
-    ['Nf2kuXAYsLBHEgU9eonYdn'],
+    [FeedV1.getFeedRootHash(keys.id, 'post')],
     'msg1.prev is root'
   )