Few DTO classes inside one DTO file

My question is simple: is it a bad practice to keep few DTOs inside one file? For example, I have a project, where few similar DTOs are used for typing:

export class CreateGenreDto {
  readonly nameRu: string;
  readonly nameEn: string;
}

export class GenreByIdDto {
  genreId: number;
}

export class UpdateGenreMessageDto extends GenreByIdDto {
  updateGenreDto: CreateGenreDto;
}

export class CreateGenreMessageDto {
  createGenreDto: CreateGenreDto;
}

For me it seems kinda annoying for eyes to have four individual files for each of DTOs.

I didn't found any information about it, so is it OK, to instead of this project structure:

/app
-/src
-/dto
--create-genre.dto.ts
--genre-by-id.dto.ts
--update-genre-message.dto.ts
--create-genre-message.dto.ts

use something like this, storing all similar DTO's in one file?

/app
-/src
-/dto
--genres.dto.ts

Thanks for your replies!

Many experts in user interface / user experience are familiar with Jakob's Law, which states "Users spend most of their time on other sites."

Stealing from this, I would argue that it doesn't matter what you think, or what I think. What matters is what most developers are used to and will expect. The standard is to separate them into separate files. There are reasons for this, and some/all of these reasons might apply to your project, but ultimately whether it's collective wisdom or collective folly doesn't matter nearly as much as what we're used to... and what future-you will therefore learn to expect... when glancing through the code.

So maybe you should put them in a genres subfolder, but they "should" be separate files.

That said, working code beats unfinished code no matter how perfect it may be. Don't worry about it too much. It will run fine either way!

(Advice you didn't ask for... Consider defining types and interfaces instead of classes. Every time I use a class, I start wanting to add methods, and then I paint myself into corners. Types and interfaces help me avoid that, and are zero-overhead at runtime.)