fix(webtorrent): ensure magnet webseeds are used in stream

Extracts `ws` (web seed) parameters from the magnet link and merges them with the explicit `urlList` (e.g., from direct URL) when initializing the WebTorrent stream. This fixes a regression where magnet-embedded web seeds were ignored if a direct URL was provided.

- Updates `js/magnets.js` to parse `ws` parameters and export `webSeedsFromMagnet`.
- Updates `js/webtorrent.js` to merge magnet web seeds with `opts.urlList`.
- Adds regression test `tests/webtorrent-webseeds.test.mjs`.

Co-authored-by: PR0M3TH3AN <[email protected]>

js/magnets.js

@@ -49,14 +49,36 @@ export function trackersFromMagnet(magnet) {
   return Array.from(deduped);
 }
 
+export function webSeedsFromMagnet(magnet) {
+  if (typeof magnet !== "string") {
+    return [];
+  }
+  const parsed = parseMagnetLite(magnet);
+  if (!parsed || !Array.isArray(parsed.ws)) {
+    return [];
+  }
+  const deduped = new Set();
+  parsed.ws.forEach((url) => {
+    if (typeof url !== "string") {
+      return;
+    }
+    const trimmed = url.trim();
+    if (!trimmed) {
+      return;
+    }
+    deduped.add(trimmed);
+  });
+  return Array.from(deduped);
+}
+
 function parseMagnetLite(magnet) {
   if (typeof magnet !== "string") {
-    return { infoHash: "", announce: [] };
+    return { infoHash: "", announce: [], ws: [] };
   }
 
   const trimmed = magnet.trim();
   if (!trimmed) {
-    return { infoHash: "", announce: [] };
+    return { infoHash: "", announce: [], ws: [] };
   }
 
   const lower = trimmed.toLowerCase();
@@ -64,6 +86,7 @@ function parseMagnetLite(magnet) {
   const paramsPart = queryIndex >= 0 ? trimmed.slice(queryIndex + 1) : "";
   const params = paramsPart.split("&");
   const announce = [];
+  const ws = [];
   let infoHash = "";
 
   for (const param of params) {
@@ -89,8 +112,12 @@ function parseMagnetLite(magnet) {
       if (value) {
         announce.push(value);
       }
+    } else if (key === "ws" || key === "webseed") {
+      if (value) {
+        ws.push(value);
+      }
     }
   }
 
-  return { infoHash, announce };
+  return { infoHash, announce, ws };
 }

js/webtorrent.js

@@ -23,7 +23,7 @@ import { WSS_TRACKERS } from "./constants.js";
 import { safeDecodeURIComponent } from "./utils/safeDecode.js";
 import { devLogger, userLogger } from "./utils/logger.js";
 import { emit } from "./embedDiagnostics.js";
-import { infoHashFromMagnet } from "./magnets.js";
+import { infoHashFromMagnet, webSeedsFromMagnet } from "./magnets.js";
 
 const DEFAULT_PROBE_TRACKERS = Object.freeze([...WSS_TRACKERS]);
 
@@ -960,15 +960,18 @@ export class TorrentClient {
       }
 
       const isFirefoxBrowser = this.isFirefox();
-      const candidateUrls = Array.isArray(opts?.urlList)
+      const explicitUrls = Array.isArray(opts?.urlList)
         ? opts.urlList
             .map((entry) => (typeof entry === "string" ? entry.trim() : ""))
             .filter((entry) => /^https?:\/\//i.test(entry))
         : [];
 
+      const magnetUrls = webSeedsFromMagnet(effectiveMagnetURI);
+      const combinedUrls = [...new Set([...explicitUrls, ...magnetUrls])];
+
       const chromeOptions = { strategy: "sequential" };
-      if (candidateUrls.length) {
-        chromeOptions.urlList = candidateUrls;
+      if (combinedUrls.length) {
+        chromeOptions.urlList = combinedUrls;
       }
 
       return new Promise((resolve, reject) => {