I am currently having some problems with types, and serializing, specifically when sending file with

fetch('something/api/route',{body: formData});

formData being formData where values are either string or File.
once i send it to /api/route I take the request object and iterate over it populating fields to formData object which is an object with keys and values

  (await request.formData()).forEach((value, key) => {
    formData[key] = value;
    console.log(key, value);
  });

once I populate formData i pass it into main() function that takes form_data argument whose type is "typeof formData"
the main function just creates a new row in a sqlite database:

async function main(form_data: typeof formData) {
  const form = await prisma.form.create({
    data: formData,
  });
  console.log(form);
}

This approach currently works perfectly for primitive types, but I have no idea how to do this for files