InferRawDocType behaves differently in v8.19 (bug?)

[Systerr]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.19

Node.js version

24

MongoDB server version

8

Typescript version (if applicable)

5

Description

In version 8.19 behavior for untyped arrays in InferRawDocType was changed.

const schema = { unTypedArray: [] };

type TSchema = InferRawDocType<typeof schema>;

It now generates the following type:

type TSchema = {
    unTypedArray: never;
}

According to the documentation:
| Note: specifying an empty array is equivalent to Mixed
https://github.com/Automattic/mongoose/blob/master/docs/schematypes.md?plain=1#L502

For the Mixed type, everything works as expected:

const schema = { mixedArray: [Schema.Types.Mixed] };

type TSchema = InferRawDocType<typeof schema>;

This generates:

type TSchema = {
   mixedArray: any[];
}

In version 8.18, both an empty array and Schema.Types.Mixed correctly generated the type any[].

Steps to Reproduce

see above

Expected Behavior

All possible schema types ([], [Mixed]) should produce correct types