types: improve function parameter types for ToObjectOptions transform option

types/index.d.ts

@@ -161,7 +161,7 @@ declare module 'mongoose' {
     [k: string]: string;
   }
 
-  export interface ToObjectOptions {
+  export interface ToObjectOptions<THydratedDocumentType = HydratedDocument<unknown>> {
     /** apply all getters (path and virtual getters) */
     getters?: boolean;
     /** apply virtual getters (can override getters option) */
@@ -171,7 +171,11 @@ declare module 'mongoose' {
     /** remove empty objects (defaults to true) */
     minimize?: boolean;
     /** if set, mongoose will call this function to allow you to transform the returned object */
-    transform?: boolean | ((doc: any, ret: any, options: any) => any);
+    transform?: boolean | ((
+      doc: THydratedDocumentType,
+      ret: Record<string, any>,
+      options: ToObjectOptions<THydratedDocumentType>
+    ) => any);
     /** if true, replace any conventionally populated paths with the original id in the output. Has no affect on virtual populated paths. */
     depopulate?: boolean;
     /** if false, exclude the version key (`__v` by default) from the output */

types/schemaoptions.d.ts

@@ -133,14 +133,14 @@ declare module 'mongoose' {
      */
     strictQuery?: boolean | 'throw';
     /** Exactly the same as the toObject option but only applies when the document's toJSON method is called. */
-    toJSON?: ToObjectOptions;
+    toJSON?: ToObjectOptions<THydratedDocumentType>;
     /**
      * Documents have a toObject method which converts the mongoose document into a plain JavaScript object.
      * This method accepts a few options. Instead of applying these options on a per-document basis, we may
      * declare the options at the schema level and have them applied to all of the schema's documents by
      * default.
      */
-    toObject?: ToObjectOptions;
+    toObject?: ToObjectOptions<THydratedDocumentType>;
     /**
      * By default, if you have an object with key 'type' in your schema, mongoose will interpret it as a
      * type declaration. However, for applications like geoJSON, the 'type' property is important. If you want to

types/types.d.ts

@@ -42,8 +42,8 @@ declare module 'mongoose' {
       shift(): T;
 
       /** Returns a native js Array. */
-      toObject(options?: ToObjectOptions): any;
-      toObject<T>(options?: ToObjectOptions): T;
+      toObject(options?: ToObjectOptions<T>): any;
+      toObject<T>(options?: ToObjectOptions<T>): T;
 
       /** Wraps [`Array#unshift`](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/unshift) with proper change tracking. */
       unshift(...args: any[]): number;