DRY

tests/discovery/mdns.js

@@ -22,28 +22,12 @@ test('mdns - discovery and sharing of data', (t) => {
   const str = 'hi'
 
   mdnsDiscovery1.on('connection', (stream) => {
-    stream.on('error', (e) => {
-      // We expected connections to be closed when duplicates happen. On the
-      // closing side the error will be ERR_DUPLICATE, but on the other side
-      // the error will be an ECONNRESET - the error is not sent over the
-      // connection
-      const expectedError =
-        e.message === ERR_DUPLICATE || e.code === 'ECONNRESET'
-      t.ok(expectedError, 'connection closed with expected error')
-    })
+    stream.on('error', handleConnectionError.bind(null, t))
     stream.write(str)
   })
 
   mdnsDiscovery2.on('connection', (stream) => {
-    stream.on('error', (e) => {
-      // We expected connections to be closed when duplicates happen. On the
-      // closing side the error will be ERR_DUPLICATE, but on the other side
-      // the error will be an ECONNRESET - the error is not sent over the
-      // connection
-      const expectedError =
-        e.message === ERR_DUPLICATE || e.code === 'ECONNRESET'
-      t.ok(expectedError, 'connection closed with expected error')
-    })
+    stream.on('error', handleConnectionError.bind(null, t))
     stream.on('data', (d) => {
       t.is(d.toString(), str, 'expected data written')
       Promise.all([
@@ -72,31 +56,15 @@ test('deduplicate incoming connections', async (t) => {
   await discovery.start()
 
   discovery.on('connection', (conn) => {
-    conn.on('error', (e) => {
-      // We expected connections to be closed when duplicates happen. On the
-      // closing side the error will be ERR_DUPLICATE, but on the other side
-      // the error will be an ECONNRESET - the error is not sent over the
-      // connection
-      const expectedError =
-        e.message === ERR_DUPLICATE || e.code === 'ECONNRESET'
-      t.ok(expectedError, 'connection closed with expected error')
-    })
+    conn.on('error', handleConnectionError.bind(null, t))
     localConnections.add(conn)
     conn.on('close', () => localConnections.delete(conn))
   })
 
   const addrInfo = discovery.address()
   for (let i = 0; i < 20; i++) {
     noiseConnect(addrInfo, remoteKp).then((conn) => {
-      conn.on('error', (e) => {
-        // We expected connections to be closed when duplicates happen. On the
-        // closing side the error will be ERR_DUPLICATE, but on the other side
-        // the error will be an ECONNRESET - the error is not sent over the
-        // connection
-        const expectedError =
-          e.message === ERR_DUPLICATE || e.code === 'ECONNRESET'
-        t.ok(expectedError, 'connection closed with expected error')
-      })
+      conn.on('error', handleConnectionError.bind(null, t))
       conn.on('connect', () => remoteConnections.add(conn))
       conn.on('close', () => remoteConnections.delete(conn))
     })
@@ -151,15 +119,7 @@ async function testMultiple(t, { period, nPeers = 20 }) {
     const conns = []
     connsById.set(peerId, conns)
     discovery.on('connection', (conn) => {
-      conn.on('error', (e) => {
-        // We expected connections to be closed when duplicates happen. On the
-        // closing side the error will be ERR_DUPLICATE, but on the other side
-        // the error will be an ECONNRESET - the error is not sent over the
-        // connection
-        const expectedError =
-          e.message === ERR_DUPLICATE || e.code === 'ECONNRESET'
-        t.ok(expectedError, 'connection closed with expected error')
-      })
+      conn.on('error', handleConnectionError.bind(null, t))
       conns.push(conn)
       if (conns.length >= nPeers - 1) onConnected()
     })
@@ -203,3 +163,12 @@ async function testMultiple(t, { period, nPeers = 20 }) {
   await Promise.all(stopPromises)
   t.pass('teardown complete')
 }
+
+function handleConnectionError(t, e) {
+  // We expected connections to be closed when duplicates happen. On the
+  // closing side the error will be ERR_DUPLICATE, but on the other side
+  // the error will be an ECONNRESET - the error is not sent over the
+  // connection
+  const expectedError = e.message === ERR_DUPLICATE || e.code === 'ECONNRESET'
+  t.ok(expectedError, 'connection closed with expected error')
+}