Fix #58 - add error listener - first step

src/commands/repl.ts

@@ -1,4 +1,4 @@
-import { bold } from 'chalk'
+import { bold, yellow } from 'chalk'
 import { Command } from 'commander'
 import cors from 'cors'
 import express from 'express'
@@ -68,7 +68,6 @@ export default async function (autoImportPath: string | undefined, options: Opti
     socket.emit('initDiagram', options)
     socket.emit('updateDiagram', getDataDiagram(interpreter))
   })
-
   repl.prompt()
 }
 
@@ -232,6 +231,17 @@ async function autocomplete(input: string): Promise<CompleterResult> {
 async function initializeClient(options: Options) {
   const app = express()
   const server = http.createServer(app)
+
+  server.addListener('error', ({ port, code }: { port: string, code: string }) => {
+    console.info('')
+    if (code === 'EADDRINUSE') {
+      console.info(yellow(bold(`Ya tenés levantado un REPL en el puerto ${port}. Si querés levantar otra instancia, utilizá la opción '--new'.`)))
+    } else {
+      console.info(yellow(bold(`No se pudo levantar el REPL en el puerto ${port}, por un código de error "${code}.`)))
+    }
+    process.exit(1)
+  })
+
   const io = new Server(server)
 
   io.on('connection', socket => {
@@ -271,4 +281,4 @@ function newImport(importNode: Import, environment: Environment) {
   return node.scope.register([imported.name!, imported])
 }
 
-export const replNode = (environment: Environment): Package => environment.getNodeByFQN<Package>('REPL')
+export const replNode = (environment: Environment): Package => environment.getNodeByFQN<Package>('REPL')