better code

src/lib/server/helpers.ts

@@ -1,7 +1,15 @@
 import formats from '$lib/common/supportedFormats.json';
 
 const formatMime = new Map(Object.entries(formats))
+export const isURLValid = (url: string) => {
+    try {
+        new URL(url)
+    } catch {
+        return false
+    }
 
+    return true;
+}
 export const mimeTypeMap = formatMime;
 export const contentTypeFromFormat = (format: string): string => {
     const toReturn: string | undefined = formatMime.get(format)

src/routes/download/+server.ts

@@ -1,9 +1,9 @@
 import { error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types';
 import { getYouTubeMetadata, streamYouTube, ytdl } from '$lib/server/ytdlp';
-import { contentTypeFromFormat, mimeTypeMap } from '$lib/server/helpers';
+import { contentTypeFromFormat, isURLValid, mimeTypeMap } from '$lib/server/helpers';
 
-export const GET: RequestHandler = async ({ url }) => {
+const validateRequest = (url) => {
 	// Get query params
 	const link = url.searchParams.get('link');
 	const format = url.searchParams.get('format'); // mp3, mp4
@@ -19,16 +19,37 @@ export const GET: RequestHandler = async ({ url }) => {
 		throw error(400, 'Currently, only YouTube is supported');
 	}
 
-	try {
+	if (!isURLValid(link)) {
+		throw error(400, 'URL not valid');
+	}
+
+	if (!mimeTypeMap.get(format)) {
+		throw error(400, 'format not valid');
+	}
+
+	return {
+		link, format, source, metadata
+	}
+}
+export const GET: RequestHandler = async ({ url }) => {
+	const { format, source, metadata, link } = validateRequest(url)
 	let filename = `you-clicked-no-metadata-so-i-cant-put-a-correct-name.${format}`;
 
 	if (metadata) {
+		try {
 			// Fetch metadata for filename
 			const metadata = await getYouTubeMetadata(link);
 			const { title, uploader } = metadata;
 			const safeTitle = `${uploader} - ${title}`;
 			filename = `${safeTitle}.${format}`;
+		} catch (err) {
+			console.error(err)
+			console.error('Error fetching metadata:');
+			throw error(500, 'Failed to fetch video metadata');
 		}
+	}
+
+	try {
 
 		// Stream video/audio
 		return new Response(streamYouTube(link, format), {
@@ -38,9 +59,10 @@ export const GET: RequestHandler = async ({ url }) => {
 				'Set-Cookie': 'downloading=0'
 			}
 		});
+
 	} catch (err) {
 		console.error(err)
-		console.error('Error fetching metadata:');
-		throw error(500, 'Failed to fetch video metadata');
+		console.error('Filed to stream file');
+		throw error(500, 'Failed to stream file');
 	}
 };