fix: fixed spr metadata being used as a file while it's a field

src/middleware/multipart.ts

@@ -0,0 +1,43 @@
+import { unlink } from 'fs/promises';
+import formidable from 'formidable';
+import RequestException from '@/request-exception';
+import type { File } from 'formidable';
+import type { Request, Response } from 'express';
+
+export type MultipartOutput = {
+	fields: Record<string, string>;
+	files: Record<string, File>;
+};
+
+export async function parseMultipart(request: Request, response: Response): Promise<MultipartOutput> {
+	const form = formidable({
+		multiples: false
+	});
+	const [fields, files] = await form.parse(request).catch((err: Error) => {
+		throw new RequestException(err.message, 400);
+	});
+
+	const fileEntries = Object.entries(files);
+	const fileEntriesUnified = fileEntries.map(v => [v[0], (v[1] ?? [])[0]] as const);
+	const fileOutput = Object.fromEntries(fileEntriesUnified);
+
+	const fieldEntries = Object.entries(fields);
+	const fieldEntriesUnified = fieldEntries.map(v => [v[0], (v[1] ?? [])[0]] as const);
+	const fieldOutput = Object.fromEntries(fieldEntriesUnified);
+
+	const cleanup = async (): Promise<void> => {
+		await Promise.allSettled(
+			Object.values(fileOutput).map(file =>
+				unlink(file.filepath).catch(() => { /* Ignore cleanup errors */ })
+			)
+		);
+	};
+
+	response.once('finish', cleanup);
+	response.once('close', cleanup);
+
+	return {
+		fields: fieldOutput,
+		files: fileOutput
+	};
+}