fix: revert to try each (libp2p#320)

Author: Alan Shaw

src/limit-dialer/index.js

@@ -1,13 +1,11 @@
 'use strict'
 
-const race = require('async/race')
+const tryEach = require('async/tryEach')
 const debug = require('debug')
-const once = require('once')
 
 const log = debug('libp2p:switch:dialer')
 
 const DialQueue = require('./queue')
-const { CONNECTION_FAILED } = require('../errors')
 
 /**
  * Track dials per peer and limited them.
@@ -39,29 +37,26 @@ class LimitDialer {
     log('dialMany:start')
     // we use a token to track if we want to cancel following dials
     const token = { cancel: false }
-    callback = once(callback) // only call callback once
 
     let errors = []
     const tasks = addrs.map((m) => {
-      return (cb) => this.dialSingle(peer, transport, m, token, (err, res) => {
-        if (res) return cb(null, res)
-
-        errors.push(err || CONNECTION_FAILED())
-
-        if (errors.length === tasks.length) {
-          cb(errors)
+      return (cb) => this.dialSingle(peer, transport, m, token, (err, result) => {
+        if (err) {
+          errors.push(err)
+          return cb(err)
         }
+        return cb(null, result)
       })
     })
 
-    race(tasks, (_, successfulDial) => {
-      if (successfulDial) {
+    tryEach(tasks, (_, result) => {
+      if (result && result.conn) {
         log('dialMany:success')
-        return callback(null, successfulDial)
+        return callback(null, result)
       }
 
       log('dialMany:error')
-      return callback(errors)
+      callback(errors)
     })
   }
 

test/limit-dialer.node.js

@@ -53,8 +53,6 @@ describe('LimitDialer', () => {
   it('two success', (done) => {
     const dialer = new LimitDialer(2, 10)
 
-    expect(2).checks(done)
-
     // mock transport
     const t1 = {
       dial (addr, cb) {
@@ -72,10 +70,7 @@ describe('LimitDialer', () => {
           setTimeout(cb, 8)
           return {
             source: pull.values([2]),
-            sink: pull.onEnd((err) => {
-              // Verify the unused connection gets closed
-              expect(err).to.not.exist().mark()
-            })
+            sink: pull.drain()
           }
         }
       }
@@ -89,7 +84,8 @@ describe('LimitDialer', () => {
         conn,
         pull.collect((err, res) => {
           expect(err).to.not.exist()
-          expect(res).to.be.eql([1]).mark()
+          expect(res).to.be.eql([1])
+          done()
         })
       )
     })