1 files changed, 18 insertions, 0 deletions
diff --git a/src/mongo/db/commands/plan_cache_commands_test.cpp b/src/mongo/db/commands/plan_cache_commands_test.cpp
index 43d0f7d3830..fb0ed6c3e03 100644
--- a/src/mongo/db/commands/plan_cache_commands_test.cpp
+++ b/src/mongo/db/commands/plan_cache_commands_test.cpp
@@ -273,6 +273,24 @@ TEST(PlanCacheCommandsTest, Canonicalize) {
     ASSERT_NOT_EQUALS(planCache.computeKey(*query), planCache.computeKey(*projectionQuery));
 }
 
+TEST(PlanCacheCommandsTest, PlanCacheIgnoresIsolated) {
+    PlanCache planCache;
+    QueryTestServiceContext serviceContext;
+    auto opCtx = serviceContext.makeOperationContext();
+
+    // Query with $isolated should generate the same key as a query without $siolated.
+    auto statusWithCQ =
+        PlanCacheCommand::canonicalize(opCtx.get(), nss.ns(), fromjson("{query: {a: 1, b: 1}}"));
+    ASSERT_OK(statusWithCQ.getStatus());
+    unique_ptr<CanonicalQuery> query = std::move(statusWithCQ.getValue());
+
+    statusWithCQ = PlanCacheCommand::canonicalize(
+        opCtx.get(), nss.ns(), fromjson("{query: {a: 1, b: 1}, $isolated: 1}"));
+    ASSERT_OK(statusWithCQ.getStatus());
+    unique_ptr<CanonicalQuery> queryWithIsolated = std::move(statusWithCQ.getValue());
+    ASSERT_EQUALS(planCache.computeKey(*query), planCache.computeKey(*queryWithIsolated));
+}
+
 /**
  * Tests for planCacheClear (single query shape)
  */