added unit test

Author: aditi-khare-mongoDB

src/mongo_types.ts

@@ -283,8 +283,8 @@ export type PullAllOperator<TSchema> = ({
 export type UpdateFilter<TSchema> = {
   $currentDate?: OnlyFieldsOfType<
     TSchema,
-    Date | Timestamp,
-    true | { $type: 'date' | 'timestamp' }
+    Date | Timestamp | true,
+    { $type: 'date' | 'timestamp' }
   >;
   $inc?: OnlyFieldsOfType<TSchema, NumericType | undefined>;
   $min?: MatchKeysAndValues<TSchema>;

test/integration/crud/find_and_modify.test.ts

@@ -1,6 +1,6 @@
 import { expect } from 'chai';
 
-import { type CommandStartedEvent, MongoServerError, ObjectId } from '../../mongodb';
+import { type Collection, type CommandStartedEvent, type Db, MongoServerError, ObjectId } from '../../mongodb';
 import { setupDatabase } from '../shared';
 
 describe('Collection (#findOneAnd...)', function () {
@@ -324,6 +324,31 @@ describe('Collection (#findOneAnd...)', function () {
         });
       });
     });
+
+    describe('update filter', function () {
+      context('when $currentDate is provided', function () {
+        let client;
+        let db: Db;
+        let collection: Collection;
+
+        beforeEach(async function () {
+          client = this.configuration.newClient({ w: 1 });
+          await client.connect();
+          db = client.db(this.configuration.db);
+          collection = db.collection('test_coll');
+          await collection.insertOne({ a: 'c' });
+        });
+
+        afterEach(async function () {
+          await collection.drop();
+          await client.close();
+        });
+
+        it(`should support fields with value 'true'`, async function () {
+          await collection.findOneAndUpdate({}, { $set: { a: 1 }, $currentDate: { lastModified: true } }, { writeConcern: { w: 1 } });
+        });
+      });
+    });
   });
 
   describe('#findOneAndReplace', function () {