Creating an API endpoint that processes multipart files and validates their size and MIME type is...

declare function makeFileInput(opts: { maxSize, allowedTypes }): (file: PersistedFile) => Effect.Effect<{
  name: string,
  path: string,
  size: bigint,
  mimeType: string,
},  FileInputError, FileSystem.FileSystem>

export const UploadSmallJPGFilesEndpoint = HttpApiEndpoint.put('uploadFiles', '/upload')
  .setPayload(
    HttpApiSchema.Multipart(
      Schema.Struct({
        files: FileInputSchema({
          maxSize: BigInt(1 * 1024 * 1024), // 1 MB
          allowedMimeTypes: ['image/jpeg'],
        }), 
      })
    )
  )
  .addError(HttpApiError.BadRequest)