refactor: add js-libp2p-switch to the libp2p codebase (#388)

Co-authored-by: Alan Shaw <alan.shaw@protocol.ai>
Co-authored-by: Alan Shaw <alan@tableflip.io>
Co-authored-by: Arnaud <arnaud.valensi@gmail.com>
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Co-authored-by: Hugo Dias <hugomrdias@gmail.com>
Co-authored-by: Jacob Heun <jacobheun@gmail.com>
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Co-authored-by: Vasco Santos <vasco.santos@ua.pt>
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Co-authored-by: kumavis <kumavis@users.noreply.github.com>
Co-authored-by: ᴠɪᴄᴛᴏʀ ʙᴊᴇʟᴋʜᴏʟᴍ <victorbjelkholm@gmail.com>

test/switch/dialSelf.spec.js

@@ -0,0 +1,88 @@
+'use strict'
+
+/* eslint-env mocha */
+
+const chai = require('chai')
+const dirtyChai = require('dirty-chai')
+const expect = chai.expect
+chai.use(dirtyChai)
+
+const { EventEmitter } = require('events')
+const PeerBook = require('peer-book')
+const Duplex = require('pull-pair/duplex')
+
+const utils = require('./utils')
+const createInfos = utils.createInfos
+const Swarm = require('libp2p-switch')
+
+class MockTransport extends EventEmitter {
+  constructor () {
+    super()
+    this.conn = Duplex()
+  }
+
+  dial (addr, cb) {
+    const c = this.conn[0]
+    this.emit('connection', this.conn[1])
+    setImmediate(() => cb(null, c))
+    return c
+  }
+
+  listen (addr, cb) {
+    return cb()
+  }
+
+  filter (mas) {
+    return Array.isArray(mas) ? mas : [mas]
+  }
+}
+
+describe(`dial self`, () => {
+  let swarmA
+  let peerInfos
+
+  before((done) => createInfos(2, (err, infos) => {
+    expect(err).to.not.exist()
+
+    const peerA = infos.shift()
+    peerInfos = infos
+
+    peerA.multiaddrs.add('/ip4/127.0.0.1/tcp/9001')
+    peerA.multiaddrs.add(`/ip4/127.0.0.1/tcp/9001/ipfs/${peerA.id.toB58String()}`)
+    peerA.multiaddrs.add(`/ip4/127.0.0.1/tcp/9001/p2p-circuit/ipfs/${peerA.id.toB58String()}`)
+    peerA.multiaddrs.add('/ip4/0.0.0.0/tcp/9001')
+    peerA.multiaddrs.add(`/ip4/0.0.0.0/tcp/9001/ipfs/${peerA.id.toB58String()}`)
+    peerA.multiaddrs.add(`/ip4/0.0.0.0/tcp/9001/p2p-circuit/ipfs/${peerA.id.toB58String()}`)
+
+    swarmA = new Swarm(peerA, new PeerBook())
+
+    swarmA.transport.add('tcp', new MockTransport())
+
+    done()
+  }))
+
+  after((done) => swarmA.stop(done))
+
+  it('node should not be able to dial itself', (done) => {
+    swarmA.dial(swarmA._peerInfo, (err, conn) => {
+      expect(err).to.exist()
+      expect(() => { throw err }).to.throw(/A node cannot dial itself/)
+      expect(conn).to.not.exist()
+      done()
+    })
+  })
+
+  it('node should not be able to dial another peers address that matches its own', (done) => {
+    const peerB = peerInfos.shift()
+    peerB.multiaddrs.add('/ip4/127.0.0.1/tcp/9001')
+    peerB.multiaddrs.add('/ip4/0.0.0.0/tcp/9001')
+    peerB.multiaddrs.add(`/ip4/0.0.0.0/tcp/9001/ipfs/${peerB.id.toB58String()}`)
+
+    swarmA.dial(peerB, (err, conn) => {
+      expect(err).to.exist()
+      expect(err.code).to.eql('CONNECTION_FAILED')
+      expect(conn).to.not.exist()
+      done()
+    })
+  })
+})