From 7bc60e9faad760d031aef2a91d63de4d937905db Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Mon, 19 Aug 2024 10:51:43 -0400
Subject: [PATCH] types: make toObject() and toJSON() not generic by default to
 avoid type widening

Fix #12883
---
 test/types/schema.test.ts  | 9 ++++++---
 types/document.d.ts        | 5 ++++-
 types/inferrawdoctype.d.ts | 5 ++++-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/test/types/schema.test.ts b/test/types/schema.test.ts
index 2d946adc93..448858750c 100644
--- a/test/types/schema.test.ts
+++ b/test/types/schema.test.ts
@@ -22,6 +22,7 @@ import {
   model,
   ValidateOpts
 } from 'mongoose';
+import { IsPathRequired } from '../../types/inferschematype';
 import { expectType, expectError, expectAssignable } from 'tsd';
 import { ObtainDocumentPathType, ResolvePathType } from '../../types/inferschematype';
 
@@ -1502,16 +1503,18 @@ function gh13772() {
   const schemaDefinition = {
     name: String,
     docArr: [{ name: String }]
-  };
+  } as const;
   const schema = new Schema(schemaDefinition);
+
+  const TestModel = model('User', schema);
   type RawDocType = InferRawDocType<typeof schemaDefinition>;
   expectAssignable<
-    { name?: string | null, docArr?: Array<{ name?: string | null }> }
+    { name?: string | null, docArr?: Array<{ name?: string | null }> | null }
   >({} as RawDocType);
 
-  const TestModel = model('User', schema);
   const doc = new TestModel();
   expectAssignable<RawDocType>(doc.toObject());
+  expectAssignable<RawDocType>(doc.toJSON());
 }
 
 function gh14696() {
diff --git a/types/document.d.ts b/types/document.d.ts
index c0fb558924..6fb01c910c 100644
--- a/types/document.d.ts
+++ b/types/document.d.ts
@@ -259,11 +259,14 @@ declare module 'mongoose' {
     set(value: string | Record<string, any>): this;
 
     /** The return value of this method is used in calls to JSON.stringify(doc). */
+    toJSON(options?: ToObjectOptions & { flattenMaps?: true }): FlattenMaps<Require_id<DocType>>;
+    toJSON(options: ToObjectOptions & { flattenMaps: false }): Require_id<DocType>;
     toJSON<T = Require_id<DocType>>(options?: ToObjectOptions & { flattenMaps?: true }): FlattenMaps<T>;
     toJSON<T = Require_id<DocType>>(options: ToObjectOptions & { flattenMaps: false }): T;
 
     /** Converts this document into a plain-old JavaScript object ([POJO](https://masteringjs.io/tutorials/fundamentals/pojo)). */
-    toObject<T = Require_id<DocType>>(options?: ToObjectOptions): Require_id<T>;
+    toObject(options?: ToObjectOptions): Require_id<DocType>;
+    toObject<T>(options?: ToObjectOptions): Require_id<T>;
 
     /** Clears the modified state on the specified path. */
     unmarkModified<T extends keyof DocType>(path: T): void;
diff --git a/types/inferrawdoctype.d.ts b/types/inferrawdoctype.d.ts
index e2b1d52b6b..5ef52e1325 100644
--- a/types/inferrawdoctype.d.ts
+++ b/types/inferrawdoctype.d.ts
@@ -1,4 +1,5 @@
 import {
+  IsPathRequired,
   IsSchemaTypeFromBuiltinClass,
   RequiredPaths,
   OptionalPaths,
@@ -14,7 +15,9 @@ declare module 'mongoose' {
     [
     K in keyof (RequiredPaths<DocDefinition, TSchemaOptions['typeKey']> &
     OptionalPaths<DocDefinition, TSchemaOptions['typeKey']>)
-    ]: ObtainRawDocumentPathType<DocDefinition[K], TSchemaOptions['typeKey']>;
+    ]: IsPathRequired<DocDefinition[K], TSchemaOptions['typeKey']> extends true
+      ? ObtainRawDocumentPathType<DocDefinition[K], TSchemaOptions['typeKey']>
+      : ObtainRawDocumentPathType<DocDefinition[K], TSchemaOptions['typeKey']> | null;
   }, TSchemaOptions>;
 
   /**