feat: change api to async / await (#112)

BREAKING CHANGE: All places in the API that used callbacks are now replaced with async/await. The API has also been updated according to the latest `interface-transport` version, https://github.com/libp2p/interface-transport/tree/v0.6.0#api.

test/compliance.spec.js

@@ -1,24 +1,43 @@
 /* eslint-env mocha */
 'use strict'
 
+const sinon = require('sinon')
 const tests = require('interface-transport')
 const multiaddr = require('multiaddr')
+const net = require('net')
 const TCP = require('../src')
 
 describe('interface-transport compliance', () => {
   tests({
-    setup (cb) {
-      const tcp = new TCP()
+    setup ({ upgrader }) {
+      const tcp = new TCP({ upgrader })
       const addrs = [
         multiaddr('/ip4/127.0.0.1/tcp/9091'),
         multiaddr('/ip4/127.0.0.1/tcp/9092'),
         multiaddr('/ip4/127.0.0.1/tcp/9093'),
         multiaddr('/dns4/ipfs.io')
       ]
-      cb(null, tcp, addrs)
-    },
-    teardown (cb) {
-      cb()
+
+      // Used by the dial tests to simulate a delayed connect
+      const connector = {
+        delay (delayMs) {
+          const netConnect = net.connect
+          sinon.replace(net, 'connect', (opts) => {
+            const socket = netConnect(opts)
+            const socketEmit = socket.emit.bind(socket)
+            sinon.replace(socket, 'emit', (...args) => {
+              const time = args[0] === 'connect' ? delayMs : 0
+              setTimeout(() => socketEmit(...args), time)
+            })
+            return socket
+          })
+        },
+        restore () {
+          sinon.restore()
+        }
+      }
+
+      return { transport: tcp, addrs, connector }
     }
   })
 })