From 1833bd3d00c6c5f271d4f899dc76ed6315cc4a55 Mon Sep 17 00:00:00 2001
From: Eric Mc Sween <5454374+emcsween@users.noreply.github.com>
Date: Tue, 15 Jul 2025 10:15:02 -0400
Subject: [PATCH] Merge pull request #27126 from
 overleaf/em-fix-persist-changes

Fix chunk creation over a one change chunk

GitOrigin-RevId: aecae334849522975b83c77224ee27db64de4ed8
---
 .../storage/lib/chunk_store/index.js          |  2 +-
 .../acceptance/js/storage/chunk_store.test.js |  3 ++-
 .../js/storage/persist_changes.test.js        | 22 +++++++++++++------
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/services/history-v1/storage/lib/chunk_store/index.js b/services/history-v1/storage/lib/chunk_store/index.js
index 286a8d8764..f387b68d90 100644
--- a/services/history-v1/storage/lib/chunk_store/index.js
+++ b/services/history-v1/storage/lib/chunk_store/index.js
@@ -246,7 +246,7 @@ async function create(projectId, chunk, earliestChangeTimestamp) {
 
   const opts = {}
   if (chunkStart > 0) {
-    const oldChunk = await backend.getChunkForVersion(projectId, chunkStart - 1)
+    const oldChunk = await backend.getChunkForVersion(projectId, chunkStart)
 
     if (oldChunk.endVersion !== chunkStart) {
       throw new ChunkVersionConflictError(
diff --git a/services/history-v1/test/acceptance/js/storage/chunk_store.test.js b/services/history-v1/test/acceptance/js/storage/chunk_store.test.js
index 8b06b8e412..df1e36e9cd 100644
--- a/services/history-v1/test/acceptance/js/storage/chunk_store.test.js
+++ b/services/history-v1/test/acceptance/js/storage/chunk_store.test.js
@@ -8,6 +8,7 @@ const { ObjectId } = require('mongodb')
 const { projects } = require('../../../../storage/lib/mongodb')
 const {
   ChunkVersionConflictError,
+  VersionNotFoundError,
 } = require('../../../../storage/lib/chunk_store/errors')
 
 const {
@@ -396,7 +397,7 @@ describe('chunkStore', function () {
             const newChunk = makeChunk([change], 7)
             await expect(
               chunkStore.create(projectId, newChunk)
-            ).to.be.rejectedWith(ChunkVersionConflictError)
+            ).to.be.rejectedWith(VersionNotFoundError)
             const latestChunk = await chunkStore.loadLatest(projectId)
             expect(latestChunk.toRaw()).to.deep.equal(thirdChunk.toRaw())
           })
diff --git a/services/history-v1/test/acceptance/js/storage/persist_changes.test.js b/services/history-v1/test/acceptance/js/storage/persist_changes.test.js
index 0bb8836cc1..4c491db4a3 100644
--- a/services/history-v1/test/acceptance/js/storage/persist_changes.test.js
+++ b/services/history-v1/test/acceptance/js/storage/persist_changes.test.js
@@ -67,7 +67,7 @@ describe('persistChanges', function () {
     expect(chunk.getChanges().length).to.equal(1)
   })
 
-  it('persists changes in two chunks', async function () {
+  it('persists changes in three chunks', async function () {
     const limitsToPersistImmediately = {
       maxChunkChanges: 1,
       minChangeTimestamp: farFuture,
@@ -84,7 +84,12 @@ describe('persistChanges', function () {
       new Date(),
       []
     )
-    const changes = [firstChange, secondChange]
+    const thirdChange = new Change(
+      [new AddFileOperation('c.tex', File.fromString(''))],
+      new Date(),
+      []
+    )
+    const changes = [firstChange, secondChange, thirdChange]
 
     await chunkStore.initializeProject(projectId)
     const result = await persistChanges(
@@ -99,20 +104,23 @@ describe('persistChanges', function () {
         'a.tex': {
           content: '',
         },
+        'b.tex': {
+          content: '',
+        },
       },
     })
-    const history = new History(snapshot, [secondChange])
-    const currentChunk = new Chunk(history, 1)
+    const history = new History(snapshot, [thirdChange])
+    const currentChunk = new Chunk(history, 2)
     expect(result).to.deep.equal({
-      numberOfChangesPersisted: 2,
+      numberOfChangesPersisted: 3,
       originalEndVersion: 0,
       currentChunk,
       resyncNeeded: false,
     })
 
     const chunk = await chunkStore.loadLatest(projectId)
-    expect(chunk.getStartVersion()).to.equal(1)
-    expect(chunk.getEndVersion()).to.equal(2)
+    expect(chunk.getStartVersion()).to.equal(2)
+    expect(chunk.getEndVersion()).to.equal(3)
     expect(chunk.getChanges().length).to.equal(1)
   })