tests passing

Author: aditi-khare-mongoDB

Diff for: src/bulk/common.ts

@@ -616,8 +616,8 @@ function handleMongoWriteConcernError(
   callback(
     new MongoBulkWriteError(
       {
-        message: err.result?.writeConcernError.errmsg,
-        code: err.result?.writeConcernError.result
+        message: err.result.writeConcernError.errmsg,
+        code: err.result.writeConcernError.code
       },
       new BulkWriteResult(bulkResult, isOrdered)
     )

Diff for: src/error.ts

@@ -1158,6 +1158,23 @@ export class MongoServerSelectionError extends MongoSystemError {
   }
 }
 
+/**
+ * The type of the result property of MongoWriteConcernError
+ * @public
+ */
+export interface WriteConcernErrorResult {
+  writeConcernError: {
+    code: number;
+    errmsg: string;
+    codeName?: string;
+    errInfo?: Document;
+  };
+  ok: number;
+  code?: number;
+  errorLabels?: string[];
+  [x: string | number]: unknown;
+}
+
 /**
  * An error thrown when the server reports a writeConcernError
  * @public
@@ -1178,16 +1195,7 @@ export class MongoWriteConcernError extends MongoServerError {
    *
    * @public
    **/
-  constructor(result: {
-    writeConcernError: {
-      code: number;
-      errmsg: string;
-      codeName?: string;
-      errInfo?: Document;
-    };
-    errorLabels?: string[];
-    code?: number;
-  }) {
+  constructor(result: WriteConcernErrorResult) {
     super({ ...result, ...result.writeConcernError });
     this.errInfo = result.writeConcernError.errInfo;
     this.result = result;

Diff for: src/index.ts

@@ -73,7 +73,8 @@ export {
   MongoTopologyClosedError,
   MongoTransactionError,
   MongoUnexpectedServerResponseError,
-  MongoWriteConcernError
+  MongoWriteConcernError,
+  WriteConcernErrorResult
 } from './error';
 export {
   AbstractCursor,

Diff for: test/unit/error.test.ts

@@ -742,16 +742,16 @@ describe('MongoErrors', () => {
   });
 
   describe('MongoWriteConcernError constructor', function () {
-    context('when no top-level code is provided and writeConcernError.code exists', function () {
-      it('error.code remains undefined', function () {
+    context('when no top-level code is provided', function () {
+      it('error.code is set to writeConcernError.code', function () {
         const res = {
           writeConcernError: {
             code: 81, // nested code
             errmsg: 'fake msg'
           },
           ok: 1
         };
-        expect(new MongoWriteConcernError(res).code).to.equal(undefined);
+        expect(new MongoWriteConcernError(res).code).to.equal(81);
       });
     });
     context('when top-level code is provided and  writeConcernError.code exists', function () {