From d8fd0fb5cefa211aaf99d4d257515737bdb60ede Mon Sep 17 00:00:00 2001
From: Renan Castro <renanccastro@gmail.com>
Date: Thu, 6 Jan 2022 20:55:35 -0300
Subject: [PATCH] Fix oplog converter case in which the value is an array but
 shouldnt be flattened

---
 packages/mongo/oplog_v2_converter.js       | 2 +-
 packages/mongo/oplog_v2_converter_tests.js | 8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/packages/mongo/oplog_v2_converter.js b/packages/mongo/oplog_v2_converter.js
index d53ad1ff61..c0420b8bc1 100644
--- a/packages/mongo/oplog_v2_converter.js
+++ b/packages/mongo/oplog_v2_converter.js
@@ -63,7 +63,7 @@ const nestedOplogEntryParsers = (
 
     return {
       ...acc,
-      ...(typeof setObjectSource[key] === 'object'
+      ...(!Array.isArray(setObjectSource[key]) && typeof setObjectSource[key] === 'object'
         ? flattenObject({ [prefixedKey]: setObjectSource[key] })
         : {
             [prefixedKey]: setObjectSource[key],
diff --git a/packages/mongo/oplog_v2_converter_tests.js b/packages/mongo/oplog_v2_converter_tests.js
index 5620c786fb..51194d0298 100644
--- a/packages/mongo/oplog_v2_converter_tests.js
+++ b/packages/mongo/oplog_v2_converter_tests.js
@@ -1,6 +1,6 @@
 import { oplogV2V1Converter } from './oplog_v2_converter';
 
-Tinytest.add('oplog - v2/v1 conversion', function(test) {
+Tinytest.only('oplog - v2/v1 conversion', function(test) {
   const entry1 = {
     $v: 2,
     diff: { scustom: { sEJSON$value: { u: { EJSONtail: 'd' } } } },
@@ -33,6 +33,8 @@ Tinytest.add('oplog - v2/v1 conversion', function(test) {
   };
   const entry8 = { $v: 2, diff: { u: { c: 'bar' }, sb: { a: true, u0: 2 } } };
 
+  const entry9 = {"$v":2,"diff":{"sservices":{"sresume":{"u":{"loginTokens":[]}}}}};
+
   test.equal(
     JSON.stringify(oplogV2V1Converter(entry1)),
     JSON.stringify({
@@ -74,4 +76,8 @@ Tinytest.add('oplog - v2/v1 conversion', function(test) {
     JSON.stringify(oplogV2V1Converter(entry8)),
     JSON.stringify({ $v: 2, $set: { 'b.0': 2, c: 'bar' } })
   );
+  test.equal(
+    JSON.stringify(oplogV2V1Converter(entry9)),
+    JSON.stringify({ '$v': 2, '$set': { 'services.resume.loginTokens': [] } })
+  );
 });