types: support readonly array in query.select

Author: omer

test/types/queries.test.ts

@@ -13,6 +13,7 @@ import {
   UpdateQuery,
   UpdateQueryKnownOnly,
   QuerySelector,
+  InferRawDocType,
   InferSchemaType,
   ProjectionFields,
   QueryOptions,
@@ -710,3 +711,17 @@ function gh14841() {
     $expr: { $lt: [{ $size: '$owners' }, 10] }
   };
 }
+
+async function gh15526() {
+  const userSchemaDefinition = { name: String, age: Number } as const;
+  const UserModel = model('User', new Schema(userSchemaDefinition));
+  type UserType = InferRawDocType<typeof userSchemaDefinition>;
+
+  const selection = ['name'] as const satisfies readonly (keyof UserType)[];
+
+  const u1 = await UserModel.findOne()
+    .select<Pick<UserType, (typeof selection)[number]>>(selection)
+    .orFail();
+  expectType<string | undefined | null>(u1.name);
+  expectError(u1.age);
+}

types/query.d.ts

@@ -758,7 +758,7 @@ declare module 'mongoose' {
 
     /** Specifies which document fields to include or exclude (also known as the query "projection") */
     select<RawDocTypeOverride extends { [P in keyof RawDocType]?: any } = {}>(
-      arg: string | string[] | Record<string, number | boolean | string | object>
+      arg: string | readonly string[] | Record<string, number | boolean | string | object>
     ): QueryWithHelpers<
       IfEquals<
         RawDocTypeOverride,