tests passing for 4.2 locally

Author: aditi-khare-mongoDB

src/cmap/connect.ts

@@ -165,7 +165,7 @@ export async function performInitialHandshake(
     } catch (error) {
       if (error instanceof MongoError) {
         error.addErrorLabel(MongoErrorLabel.HandshakeError);
-        if (needsRetryableWriteLabel(error, response.maxWireVersion, isSharded(conn))) {
+        if (needsRetryableWriteLabel(error, response.maxWireVersion, conn.description.type)) {
           error.addErrorLabel(MongoErrorLabel.RetryableWriteError);
         }
       }

src/error.ts

@@ -1,4 +1,5 @@
 import type { Document } from './bson';
+import { ServerType } from './sdam/common';
 import type { TopologyVersion } from './sdam/server_description';
 import type { TopologyDescription } from './sdam/topology_description';
 
@@ -1217,10 +1218,18 @@ const RETRYABLE_READ_ERROR_CODES = new Set<number>([
 // see: https://github.com/mongodb/specifications/blob/master/source/retryable-writes/retryable-writes.rst#terms
 const RETRYABLE_WRITE_ERROR_CODES = RETRYABLE_READ_ERROR_CODES;
 
+const REPLICASET_SERVER_TYPES: ServerType[] = [
+  ServerType.RSPrimary,
+  ServerType.RSSecondary,
+  ServerType.RSArbiter,
+  ServerType.RSOther,
+  ServerType.RSGhost
+];
+
 export function needsRetryableWriteLabel(
   error: Error,
   maxWireVersion: number,
-  isSharded: boolean
+  serverType: ServerType
 ): boolean {
   // pre-4.4 server, then the driver adds an error label for every valid case
   // execute operation will only inspect the label, code/message logic is handled here
@@ -1240,14 +1249,25 @@ export function needsRetryableWriteLabel(
     }
   }
 
-  // For writeConcernErrors from a pre-4.4 mongos response, do not use the error code to determine retryability.
-  const isShardedAndPre4_4 = isSharded && maxWireVersion < 9;
-  if (error instanceof MongoWriteConcernError && !isShardedAndPre4_4) {
-    return RETRYABLE_WRITE_ERROR_CODES.has(error.result?.code ?? error.code ?? 0);
+  // Logic for pre-4.4 server responses from mongos and mongod servers
+  if (maxWireVersion < 9 && ['Mongos', ...REPLICASET_SERVER_TYPES].includes(serverType)) {
+    // In pre-4.4 servers, use error code to determine retryability for writeConcernErrors in only mongod responses.
+    if (REPLICASET_SERVER_TYPES.includes(serverType) && error instanceof MongoWriteConcernError) {
+      return RETRYABLE_WRITE_ERROR_CODES.has(error.result?.code ?? Number(error.code) ?? 0);
+    }
+    // In pre-4.4 servers, use error code to determine retryability for non-writeConcernErrors in mongod and mongos responses.
+    if (!(error instanceof MongoWriteConcernError) && error instanceof MongoError) {
+      return RETRYABLE_WRITE_ERROR_CODES.has(Number(error.code) ?? 0);
+    }
+    return false;
+  }
+
+  if (error instanceof MongoWriteConcernError) {
+    return RETRYABLE_WRITE_ERROR_CODES.has(error.result?.code ?? Number(error.code) ?? 0);
   }
 
   if (error instanceof MongoError && typeof error.code === 'number') {
-    return RETRYABLE_WRITE_ERROR_CODES.has(error.code);
+    return RETRYABLE_WRITE_ERROR_CODES.has(Number(error.code));
   }
 
   const isNotWritablePrimaryError = LEGACY_NOT_WRITABLE_PRIMARY_ERROR_MESSAGE.test(error.message);

src/sdam/server.ts

@@ -454,7 +454,7 @@ export class Server extends TypedEventEmitter<ServerEvents> {
     } else {
       if (
         (isRetryableWritesEnabled(this.topology) || isTransactionCommand(cmd)) &&
-        needsRetryableWriteLabel(error, maxWireVersion(this), isSharded(this)) &&
+        needsRetryableWriteLabel(error, maxWireVersion(this), this.s.description.type) &&
         !inActiveTransaction(session, cmd)
       ) {
         error.addErrorLabel(MongoErrorLabel.RetryableWriteError);

test/integration/retryable-writes/retryable_writes.spec.test.ts

@@ -203,6 +203,6 @@ async function turnOffFailPoint(client, name) {
   });
 }
 
-describe.only('Retryable Writes (unified)', function () {
+describe('Retryable Writes (unified)', function () {
   runUnifiedSuite(loadSpecTests(path.join('retryable-writes', 'unified')));
 });