Add connections to stats (opened, closed, attempted)

index.js

@@ -56,7 +56,14 @@ module.exports = class Hyperswarm extends EventEmitter {
     this.peers = new Map()
     this.explicitPeers = new Set()
     this.listening = null
-    this.stats = { updates: 0 }
+    this.stats = {
+      updates: 0,
+      connections: {
+        opened: 0,
+        closed: 0,
+        attempted: 0
+      }
+    }
 
     this._discovery = new Map()
     this._timer = new RetryTimer(this._requeue.bind(this), {
@@ -169,12 +176,16 @@ module.exports = class Hyperswarm extends EventEmitter {
     })
     this._allConnections.add(conn)
 
+    this.stats.connections.attempted++
+
     this.connecting++
     this._clientConnections++
     let opened = false
 
     conn.on('open', () => {
       opened = true
+      this.stats.connections.opened++
+
       this._connectDone()
       this.connections.add(conn)
       conn.removeListener('error', noop)
@@ -194,6 +205,8 @@ module.exports = class Hyperswarm extends EventEmitter {
     })
     conn.on('close', () => {
       if (!opened) this._connectDone()
+      this.stats.connections.closed++
+
       this.connections.delete(conn)
       this._allConnections.delete(conn)
       this._clientConnections--

test/all.js

@@ -14,6 +14,7 @@ async function runTests () {
   await import('./peer-join.js')
   await import('./retry-timer.js')
   await import('./suspend.js')
+  await import('./stats.js')
   await import('./swarm.js')
   await import('./update.js')
 

test/stats.js

@@ -0,0 +1,44 @@
+const test = require('brittle')
+const createTestnet = require('hyperdht/testnet')
+
+const Hyperswarm = require('..')
+
+test('connectionsOpened and connectionsClosed stats', async (t) => {
+  const { bootstrap } = await createTestnet(3, t.teardown)
+
+  const swarm1 = new Hyperswarm({ bootstrap })
+  const swarm2 = new Hyperswarm({ bootstrap })
+
+  const tOpen = t.test('Open connection')
+  tOpen.plan(2)
+  const tClose = t.test('Close connection')
+  tClose.plan(2)
+
+  t.teardown(async () => {
+    await swarm1.destroy()
+    await swarm2.destroy()
+  })
+
+  swarm2.on('connection', (conn) => {
+    conn.on('error', noop)
+    tOpen.is(swarm2.stats.connections.opened, 1, 'opened connection is in stats')
+    tOpen.is(swarm2.stats.connections.attempted, 1, 'attemped connection is in stats')
+    tClose.is(swarm2.stats.connections.closed, 0, 'sanity check')
+
+    conn.on('close', () => {
+      tClose.is(swarm2.stats.connections.closed, 1, 'closed connection is in stats')
+    })
+
+    conn.destroy()
+  })
+
+  swarm1.on('connection', (conn) => {
+    conn.on('error', noop)
+  })
+
+  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 () {}