From 00ef66bb95f298203b18990805a3206a8fe6f704 Mon Sep 17 00:00:00 2001
From: kptdobe <acapt@adobe.com>
Date: Thu, 30 Apr 2026 08:55:39 +0200
Subject: [PATCH] fix: treat putVersion 412 as version-already-exists, not
 failure
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When multiple concurrent POST /versionsource requests target the same
document (e.g. the localization pipeline processing many locales in
parallel), the second caller's R2 PUT for the version object gets a 412
PreconditionFailed because the first caller already wrote it with
If-None-Match:*. The version IS in R2 — returning 500 "Version was not
created" is incorrect.

Fixes ~860 spurious 500 errors per 24h on /versionsource/adobecom/da-cc.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/storage/version/put.js       |  4 +++-
 test/storage/version/put.test.js | 17 ++++++++---------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/storage/version/put.js b/src/storage/version/put.js
index 92fc291..aa1d5de 100644
--- a/src/storage/version/put.js
+++ b/src/storage/version/put.js
@@ -242,7 +242,9 @@ export async function putObjectWithVersion(
     if (versionResp.status !== 200 && versionResp.status !== 412) {
       return { status: versionResp.status, metadata: { id: ID } };
     }
-    versionCreated = versionResp.status === 200;
+    // 412 means the version key already exists — a concurrent request created it first.
+    // The version IS persisted in R2, so treat it as created.
+    versionCreated = versionResp.status === 200 || versionResp.status === 412;
   }
 
   // Audit: one entry per versionable PUT; versionLabel + versionId when labelled version created.
diff --git a/test/storage/version/put.test.js b/test/storage/version/put.test.js
index 8987843..7d16ef7 100644
--- a/test/storage/version/put.test.js
+++ b/test/storage/version/put.test.js
@@ -2228,7 +2228,7 @@ describe('Version Put', () => {
     assert.strictEqual(true, resp.versionCreated);
   });
 
-  it('putObjectWithVersion sets versionCreated false when version already existed (putVersion 412)', async () => {
+  it('putObjectWithVersion sets versionCreated true when version already existed (putVersion 412 = concurrent race)', async () => {
     const mockGetObject = async () => ({
       body: 'content',
       contentType: 'text/html',
@@ -2261,10 +2261,10 @@ describe('Version Put', () => {
       org: 'o', key: 'a.html', body: 'new', label: 'My version',
     }, true);
     assert.equal(200, resp.status);
-    assert.strictEqual(false, resp.versionCreated);
+    assert.strictEqual(true, resp.versionCreated);
   });
 
-  it('postObjectVersion returns 500 when version was not created (putVersion 412)', async () => {
+  it('postObjectVersion returns 201 when version already exists in R2 (putVersion 412 concurrent race)', async () => {
     const req = { json: async () => ({ label: 'my-label' }) };
     const env = {};
     const ctx = {
@@ -2299,8 +2299,7 @@ describe('Version Put', () => {
     });
 
     const resp = await postObjectVersion(req, env, ctx);
-    assert.equal(500, resp.status);
-    assert.strictEqual(resp.error, 'Version was not created');
+    assert.equal(201, resp.status);
   });
 
   it('postObjectVersion returns 201 when version is successfully created', async () => {
@@ -3029,7 +3028,7 @@ describe('Version Put', () => {
       assert.equal(201, resp.status);
     });
 
-    it('returns 500 when versionCreated is false (version already exists / 412)', async () => {
+    it('returns 201 when version PUT gets 412 (concurrent race — version already exists in R2)', async () => {
       const mockGetObject = async () => ({
         body: 'doc content',
         contentType: 'text/html',
@@ -3043,7 +3042,8 @@ describe('Version Put', () => {
           return { $metadata: { httpStatusCode: 200 } };
         },
       };
-      // version put throws 412 → putVersion returns { status: 412 } → versionCreated stays false
+      // Concurrent request already created the version object; R2 returns 412 on our PUT.
+      // The version IS persisted — this request should still return 201, not 500.
       const versionClient = {
         async send() {
           const err = new Error('precondition failed');
@@ -3069,8 +3069,7 @@ describe('Version Put', () => {
       };
       const resp = await postObjectVersionWithLabel('My Label', {}, daCtx);
 
-      assert.strictEqual(resp.status, 500, 'must return 500 when version was not created');
-      assert.strictEqual(resp.error, 'Version was not created');
+      assert.strictEqual(resp.status, 201, 'must return 201 when version already exists (concurrent 412)');
     });
 
     it('returns 201 when version client body is a ReadableStream that would be disturbed by SDK retry', async () => {