fix: make utp-native optional (#1966)

* Add optional utp-native

* Add error log when uTP cannot be loaded

* Fix review suggestions

* Remove an additional require call

Co-authored-by: Alex <alxmorais8@msn.com>

3 files changed, 13 insertions, 3 deletions

diff --git a/lib/conn-pool.js b/lib/conn-pool.js
index 1ed49d9..004a4cd 100644
--- a/lib/conn-pool.js
+++ b/lib/conn-pool.js
@@ -1,9 +1,9 @@
 const debug = require('debug')('webtorrent:conn-pool')
 const net = require('net') // browser exclude
-const utp = require('utp-native') // browser exclude
 const queueMicrotask = require('queue-microtask')
 
 const Peer = require('./peer')
+const utp = require('./utp') // browser exclude
 
 /**
  * Connection Pool
@@ -162,6 +162,8 @@ class ConnPool {
   }
 }
 
+ConnPool.UTP_SUPPORT = Object.keys(utp).length > 0
+
 function noop () {}
 
 module.exports = ConnPool
diff --git a/lib/torrent.js b/lib/torrent.js
index 8ab87ff..24e7b44 100644
--- a/lib/torrent.js
+++ b/lib/torrent.js
@@ -26,13 +26,13 @@ const randomIterate = require('random-iterate')
 const sha1 = require('simple-sha1')
 const speedometer = require('speedometer')
 const utMetadata = require('ut_metadata')
-const utp = require('utp-native') // browser exclude
 const utPex = require('ut_pex') // browser exclude
 
 const File = require('./file')
 const Peer = require('./peer')
 const RarityMap = require('./rarity-map')
 const Server = require('./server') // browser exclude
+const utp = require('./utp') // browser exclude
 const WebConn = require('./webconn')
 
 const MAX_BLOCK_LENGTH = 128 * 1024
@@ -1752,7 +1752,7 @@ class Torrent extends EventEmitter {
       port: parts[1]
     }
 
-    if (peer.type === 'utpOutgoing') {
+    if (this.client.utp && peer.type === 'utpOutgoing') {
       peer.conn = utp.connect(opts.port, opts.host)
     } else {
       peer.conn = net.connect(opts)
diff --git a/lib/utp.js b/lib/utp.js
new file mode 100644
index 0000000..2cde3f4
--- /dev/null
+++ b/lib/utp.js
@@ -0,0 +1,8 @@
+module.exports = (() => {
+  try {
+    return require('utp-native')
+  } catch (err) {
+    console.warn('WebTorrent: uTP not supported')
+    return {}
+  }
+})()