chore(NODE-7418): skip csot change stream tests on sharded topology

test/integration/client-side-operations-timeout/client_side_operations_timeout.spec.test.ts

@@ -52,13 +52,54 @@ describe('CSOT spec tests', function () {
     ) {
       return '4.4 replicaset fail point does not blockConnection for requested time';
     }
+    // TODO(NODE-7418): on sharded clusters the initial $changeStream aggregate blocks server-side
+    // for the full maxTimeMS because mongos propagates maxTimeMS to each shard as maxAwaitTimeMS.
+    // The legacy-timeout retryability tests also fail because socketTimeoutMS=100 is too tight for
+    // SSL connection establishment on a sharded+SSL Evergreen host.
+    if (
+      configuration.topologyType === 'Sharded' &&
+      csotChangeStreamShardedSkips.has(test.description)
+    ) {
+      return 'TODO(NODE-7418): CSOT createChangeStream tests hang on sharded clusters, fixed by NODE-7418';
+    }
     return false;
   });
 });
 
+// Descriptions of CSOT change stream tests that fail specifically on sharded topologies.
+// On sharded clusters, mongos propagates maxTimeMS to each shard as maxAwaitTimeMS on the
+// initial $changeStream aggregate, causing the server to block for the full budget.
+// The legacy timeout tests additionally fail because socketTimeoutMS=100 is too tight
+// for SSL connection establishment overhead on sharded+SSL CI hosts.
+// Tracked in NODE-7418 / DRIVERS-3018.
+const csotChangeStreamShardedSkips = new Set([
+  'change stream can be iterated again if previous iteration times out',
+  'timeoutMS can be configured on a MongoCollection - createChangeStream on collection',
+  'timeoutMS can be configured on a MongoDatabase - createChangeStream on database',
+  'timeoutMS can be configured on a MongoDatabase - createChangeStream on collection',
+  'timeoutMS can be configured for an operation - createChangeStream on client',
+  'timeoutMS can be configured for an operation - createChangeStream on database',
+  'timeoutMS can be configured for an operation - createChangeStream on collection',
+  'operation succeeds after one socket timeout - createChangeStream on client',
+  'operation succeeds after one socket timeout - createChangeStream on database',
+  'operation succeeds after one socket timeout - createChangeStream on collection',
+  'operation is retried multiple times for non-zero timeoutMS - createChangeStream on client',
+  'operation is retried multiple times for non-zero timeoutMS - createChangeStream on database',
+  'operation is retried multiple times for non-zero timeoutMS - createChangeStream on collection'
+]);
+
 describe('CSOT modified spec tests', function () {
   const specs = loadSpecTests(
     join('..', 'integration', 'client-side-operations-timeout', 'unified-csot-node-specs')
   );
-  runUnifiedSuite(specs);
+  runUnifiedSuite(specs, (test, configuration) => {
+    // TODO(NODE-7418): same root cause as csotChangeStreamShardedSkips above.
+    if (
+      configuration.topologyType === 'Sharded' &&
+      test.description === 'timeoutMS is refreshed for getMore if maxAwaitTimeMS is set'
+    ) {
+      return 'TODO(NODE-7418): CSOT createChangeStream tests hang on sharded clusters, fixed by NODE-7418';
+    }
+    return false;
+  });
 });