From ec212309f666fc04276d40c921090bea5b5d0e37 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 4 Apr 2024 14:39:24 -0400
Subject: [PATCH] types(validation): support function for validator `message`
 property, and add support for accessing validator `reason`

Fix #14496
---
 test/types/schema.test.ts | 17 +++++++++++++++++
 types/schematypes.d.ts    |  3 ++-
 types/validation.d.ts     |  1 +
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/test/types/schema.test.ts b/test/types/schema.test.ts
index e7631229036..de80dc0de73 100644
--- a/test/types/schema.test.ts
+++ b/test/types/schema.test.ts
@@ -1407,3 +1407,20 @@ function gh14235() {
   userSchema.omit<Omit<IUser, 'age'>>(['age']);
 }
 
+function gh14496() {
+  const schema = new Schema({
+    name: {
+      type: String
+    }
+  });
+  schema.path('name').validate({
+    validator: () => {
+      throw new Error('Oops!');
+    },
+    // `errors['name']` will be "Oops!"
+    message: (props) => {
+      expectType<Error | undefined>(props.reason);
+      return 'test';
+    }
+  });
+}
diff --git a/types/schematypes.d.ts b/types/schematypes.d.ts
index 9cb48343009..778b83c7ad5 100644
--- a/types/schematypes.d.ts
+++ b/types/schematypes.d.ts
@@ -193,9 +193,10 @@ declare module 'mongoose' {
   }
 
   interface Validator<DocType = any> {
-    message?: string;
+    message?: string | ((props: ValidatorProps) => string);
     type?: string;
     validator?: ValidatorFunction<DocType>;
+    reason?: Error;
   }
 
   type ValidatorFunction<DocType = any> = (this: DocType, value: any, validatorProperties?: Validator) => any;
diff --git a/types/validation.d.ts b/types/validation.d.ts
index 693261250e7..488ead7e588 100644
--- a/types/validation.d.ts
+++ b/types/validation.d.ts
@@ -6,6 +6,7 @@ declare module 'mongoose' {
     path: string;
     fullPath: string;
     value: any;
+    reason?: Error;
   }
 
   interface ValidatorMessageFn {