Bugfix: remove initial error handler when a conn opens (#180)

* Bugfix: remove initial error handler when a conn opens

* rename to onerror

---------

Co-authored-by: Mathias Buus <[email protected]>

index.js

@@ -187,27 +187,31 @@ module.exports = class Hyperswarm extends EventEmitter {
     this._clientConnections++
     let opened = false
 
+    const onerror = (err) => {
+      if (this.relayThrough && shouldForceRelaying(err.code)) {
+        peerInfo.forceRelaying = true
+        // Reset the attempts in order to fast connect to relay
+        peerInfo.attempts = 0
+      }
+    }
+
+    // Removed once a connection is opened
+    conn.on('error', onerror)
+
     conn.on('open', () => {
       opened = true
       this.stats.connects.client.opened++
 
       this._connectDone()
       this.connections.add(conn)
-      conn.removeListener('error', noop)
+      conn.removeListener('error', onerror)
       peerInfo._connected()
       peerInfo.client = true
       this.emit('connection', conn, peerInfo)
       this._flushMaybe(peerInfo)
 
       this.emit('update')
     })
-    conn.on('error', err => {
-      if (this.relayThrough && shouldForceRelaying(err.code)) {
-        peerInfo.forceRelaying = true
-        // Reset the attempts in order to fast connect to relay
-        peerInfo.attempts = 0
-      }
-    })
     conn.on('close', () => {
       if (!opened) this._connectDone()
       this.stats.connects.client.closed++

test/swarm.js

@@ -681,6 +681,35 @@ test('peer-discovery object deleted when corresponding connection closes (client
   await swarm1.destroy()
 })
 
+test('no default error handler set when connection event is emitted', async (t) => {
+  t.plan(2)
+
+  const { bootstrap } = await createTestnet(3, t.teardown)
+
+  const swarm1 = new Hyperswarm({ bootstrap })
+  const swarm2 = new Hyperswarm({ bootstrap })
+
+  t.teardown(async () => {
+    await swarm1.destroy()
+    await swarm2.destroy()
+  })
+
+  swarm2.on('connection', (conn) => {
+    t.is(conn.listeners('error').length, 0, 'no error listeners')
+    conn.on('error', noop)
+    conn.end()
+  })
+  swarm1.on('connection', (conn) => {
+    t.is(conn.listeners('error').length, 0, 'no error listeners')
+    conn.on('error', noop)
+    conn.end()
+  })
+
+  const topic = Buffer.alloc(32).fill('hello world')
+  await swarm1.join(topic, { server: true, client: false }).flushed()
+  swarm2.join(topic, { client: true, server: false })
+})
+
 function noop () {}
 
 function eventFlush () {