Merge pull request #1083 from ethereum/sim_ws

add websocket support for remix-sim

remix-simulator/package.json

@@ -22,6 +22,7 @@
     "body-parser": "^1.18.2",
     "color-support": "^1.1.3",
     "express": "^4.16.3",
+    "express-ws": "^4.0.0",
     "fast-async": "^6.3.7",
     "merge": "^1.2.0",
     "remix-lib": "0.3.13",

remix-simulator/src/server.js

@@ -1,9 +1,12 @@
 const express = require('express')
 const bodyParser = require('body-parser')
 const app = express()
+const expressWs = require('express-ws')
 const Provider = require('./provider')
 const log = require('./utils/logs.js')
 
+expressWs(app)
+
 var provider = new Provider()
 
 app.use(bodyParser.urlencoded({extended: true}))
@@ -13,13 +16,24 @@ app.get('/', (req, res) => {
   res.send('Welcome to remix-simulator')
 })
 
-app.use(function (req, res) {
+app.use((req, res) => {
   provider.sendAsync(req.body, (err, jsonResponse) => {
     if (err) {
-      res.send({error: err})
+      return res.send(JSON.stringify({error: err}))
     }
     res.send(jsonResponse)
   })
 })
 
+app.ws('/', (ws, req) => {
+  ws.on('message', function (msg) {
+    provider.sendAsync(JSON.parse(msg), (err, jsonResponse) => {
+      if (err) {
+        return ws.send(JSON.stringify({error: err}))
+      }
+      ws.send(JSON.stringify(jsonResponse))
+    })
+  })
+})
+
 app.listen(8545, () => log('Remix Simulator listening on port 8545!'))