fix: stop stream after first pong received (#545)

When connecting to go-IPFS from a webworker, the stream opened by
the ping protocol is never closed.

The change here uses `take` to only receive one buffer from the
remote node before closing the stream.

src/ping/index.js

@@ -8,7 +8,7 @@ const errCode = require('err-code')
 const crypto = require('libp2p-crypto')
 const pipe = require('it-pipe')
 const { toBuffer } = require('it-buffer')
-const { collect } = require('streaming-iterables')
+const { collect, take } = require('streaming-iterables')
 
 const { PROTOCOL, PING_LENGTH } = require('./constants')
 
@@ -29,6 +29,7 @@ async function ping (node, peer) {
  const [result] = await pipe(
  [data],
  stream,
+ stream => take(1, stream),
  toBuffer,
  collect
  )

test/core/ping.node.js

@@ -6,9 +6,11 @@ chai.use(require('dirty-chai'))
 const { expect } = chai
 
 const pTimes = require('p-times')
+const pipe = require('it-pipe')
 
 const peerUtils = require('../utils/creators/peer')
 const baseOptions = require('../utils/base-options')
+const { PROTOCOL } = require('../../src/ping/constants')
 
 describe('ping', () => {
  let nodes
@@ -32,4 +34,40 @@ describe('ping', () => {
  const averageLatency = latencies.reduce((p, c) => p + c, 0) / latencies.length
  expect(averageLatency).to.be.a('Number')
  })
+
+ it('only waits for the first response to arrive', async () => {
+ nodes[1].handle(PROTOCOL, async ({ connection, stream }) => {
+ let firstInvocation = true
+
+ await pipe(
+ stream,
+ function (stream) {
+ const output = {
+ [Symbol.asyncIterator]: () => output,
+ next: async () => {
+ if (firstInvocation) {
+ firstInvocation = false
+
+ for await (const data of stream) {
+ return {
+ value: data,
+ done: false
+ }
+ }
+ } else {
+ return new Promise() // never resolve
+ }
+ }
+ }
+
+ return output
+ },
+ stream
+ )
+ })
+
+ const latency = await nodes[0].ping(nodes[1].peerInfo)
+
+ expect(latency).to.be.a('Number')
+ })
 })