Don't spam refresh if there are <3 nodes to ping

lib/announcer.js

@@ -113,7 +113,9 @@ module.exports = class Announcer {
           }
 
           const active = await resolved(pings)
-          if (active < MIN_ACTIVE) this.refresh() // we lost too many relay nodes, retry all
+          if (active < Math.min(pings.length, MIN_ACTIVE)) {
+            this.refresh() // we lost too many relay nodes, retry all
+          }
 
           if (this.stopped) return
 

test/announces.js

@@ -1,6 +1,7 @@
 const test = require('brittle')
 const { swarm, toArray } = require('./helpers')
 const DHT = require('../')
+const HyperDHT = require('../')
 
 test('server listen and findPeer', async function (t) {
   const [a, b] = await swarm(t)
@@ -158,3 +159,32 @@ test('connect when we relay ourself', async function (t) {
     }
   }
 })
+
+test('announcer background does not over-trigger', async function (t) {
+  // Note: Not a great test, since it accesses private prop of dht-rpc/io
+  // Feel free to remove this test if _tid behaviour changes, since it's
+  // mostly used to document a previous bug
+
+  const testnet = await swarm(t, 2) // must be <=3 (less than announcer MIN_ACTIVE) to trigger previous bug
+  const bootstrap = testnet.bootstrap
+
+  const a = new HyperDHT({ bootstrap })
+
+  const initTid = a.io._tid
+  const server = a.createServer()
+  await server.listen()
+
+  // give some time for possible background spam
+  await new Promise(resolve => setTimeout(resolve, 500))
+
+  const requestsSent = initTid > 65536 - 50
+    ? a.io._tid // close enough for this test (ignoring those before wrapping)
+    : a.io._tid - initTid
+
+  t.ok(
+    requestsSent < 50,
+    'No background spam of ping requests'
+  )
+
+  await a.destroy()
+})