A single parsed file from a multipart upload.
readonly
name: string
The form field name the file was uploaded under (Content-Disposition name="…").
readonly
filename: string
The client-provided original file name (Content-Disposition filename="…").
Always present: since M94b a part carrying NO filename under the field
name is a plain form value, not an upload (an empty filename="" — an
empty file input — still is one).
readonly
data: Uint8Array
File bytes.
readonly
mimeType: string
MIME type reported by the client.
readonly
size: number
File size in bytes.