fix(index.d.ts): allow using Types.ObjectId() without new in Type…

…Script

Fix #9608

index.d.ts

@@ -1302,10 +1302,21 @@ declare module "mongoose" {
       toObject(options: ToObjectOptions & { flattenMaps?: boolean }): any;
     }
 
-    class ObjectId extends mongodb.ObjectID {
+    var ObjectId: ObjectIdConstructor;
+
+    class _ObjectId extends mongodb.ObjectID {
       _id?: ObjectId;
     }
 
+    // Expose static methods of `mongodb.ObjectID` and allow calling without `new`
+    type ObjectIdConstructor = typeof _ObjectId & {
+      (val?: string | number): ObjectId;
+    };
+
+    // var objectId: mongoose.Types.ObjectId should reference mongodb.ObjectID not
+    //   the ObjectIdConstructor, so we add the interface below
+    interface ObjectId extends mongodb.ObjectID {}
+
     class Subdocument extends Document {
       $isSingleNested: true;
 

test/typescript/main.test.js

@@ -140,6 +140,14 @@ describe('typescript syntax', function() {
     assert.equal(errors.length, 1);
     assert.ok(errors[0].messageText.includes('Property \'create\' does not exist'), errors[0].messageText);
   });
+
+  it('objectid', function() {
+    const errors = runTest('objectid.ts');
+    if (process.env.D && errors.length) {
+      console.log(errors);
+    }
+    assert.equal(errors.length, 0);
+  });
 });
 
 function runTest(file) {

test/typescript/objectid.ts

@@ -0,0 +1,7 @@
+import { Types } from 'mongoose';
+
+const oid = new Types.ObjectId();
+oid.toHexString();
+oid._id;
+
+Types.ObjectId().toHexString();