Pipeline modifying asset before type generation

[muatide]

I am using a custom transformer to modify an asset (.ts file) - it removes certain parts of that file. I have added that transfomer as the first in the pipeline. This works fine for bundling. Now, I would also like to generate type definitions. So, I have added the same transformer in the 'types' pipeline:

{
  "extends": "@parcel/config-default",
  "transformers": {
    "*.{js,ts,jsx,tsx}": ["./parcel-transformer/preprocessor", "..."],
    "types:*.{ts,tsx}": ["./parcel-transformer/preprocessor", "..."]
  }
}

Now, the default transformer for type generation is "@parcel/transformer-typescript-types". It seems to me that this transformer does not use the asset.code property for further processing but only asset.filePath to access the file directly from filesystem. Therefore, changes of the preprocessor are ignored in generated types.

What would be a good way to handle this situation?