Better error handling for child processes

app/src/main/index.js

@@ -169,8 +169,10 @@ function startProcess (name, args, env) {
   child.on('exit', (code) => !shuttingDown && log(`${name} exited with code ${code}`))
   child.on('error', function (err) {
     if (!(shuttingDown && err.code === 'ECONNRESET')) {
-      // Ignore ECONNRESET and re throw anything else
-      throw err
+      // if we throw errors here, they are not handled by the main process
+      console.error('[Uncaught Exception] Child', name, 'produced an unhandled exception:', err)
+      console.log('Shutting down UI')
+      shutdown()
     }
   })
   return child

package.json

@@ -113,9 +113,8 @@
     "flatpickr": "^4.1.2",
     "fs-extra": "^5.0.0",
     "glob": "^7.1.2",
-    "jszip": "^3.1.5",
     "interactjs": "^1.3.3",
-    "kill-port": "^1.0.0",
+    "jszip": "^3.1.5",
     "moment": "^2.17.1",
     "mousetrap": "^1.6.1",
     "nib": "^1.1.2",

tasks/runner.js

@@ -3,7 +3,6 @@
 const config = require('../config')
 const spawn = require('child_process').spawn
 const path = require('path')
-const killPort = require('kill-port')
 
 let YELLOW = '\x1b[33m'
 let BLUE = '\x1b[34m'
@@ -12,6 +11,24 @@ let END = '\x1b[0m'
 let NPM_BIN = path.join(path.dirname(__dirname), 'node_modules', '.bin')
 let PATH = `${NPM_BIN}:${process.env.PATH}`
 
+// on windows some processes are not exiting when using child.kill so we use a windows specific comand
+function cleanExitChild (child) {
+  return new Promise((resolve, reject) => {
+    var isWin = /^win/.test(process.platform)
+    if (!isWin) {
+      child.kill('SIGTERM')
+    } else {
+      var cp = require('child_process')
+      cp.exec('taskkill /PID ' + child.pid + ' /T /F', function (error, stdout, stderr) {
+        if (error !== null) {
+          console.log('exec error: ' + error)
+        }
+      })
+    }
+    child.on('exit', resolve)
+  })
+}
+
 function format (command, data, color) {
   return color + command + END +
     '  ' + // Two space offset
@@ -31,7 +48,6 @@ function run (command, color, name, env) {
   child.on('exit', code => {
     console.log('exited', command, code)
   })
-  process.on('exit', () => child.kill('SIGKILL'))
   return child
 }
 
@@ -49,7 +65,7 @@ function startRendererServer () {
 }
 
 module.exports = async function (networkPath) {
-  await startRendererServer()
+  let renderProcess = await startRendererServer()
 
   console.log(`${BLUE}Starting electron...\n  (network path: ${networkPath})\n${END}`)
   let env = Object.assign({}, {
@@ -59,9 +75,9 @@ module.exports = async function (networkPath) {
   let mainProcess = run('electron app/src/main/index.dev.js', BLUE, 'electron', env)
 
   // terminate running processes on exit of main process
-  mainProcess.on('exit', code => {
+  mainProcess.on('exit', async code => {
+    await cleanExitChild(renderProcess)
     // webpack-dev-server spins up an own process we have no access to. so we kill all processes on our port
-    killPort(config.port)
     process.exit(0)
   })
 }

tasks/testnet.js

@@ -39,4 +39,6 @@ async function main () {
   }
 }
 
-main().catch(function (err) { throw err })
+main().catch(function (err) {
+  console.error('Starting the application failed', err)
+})

yarn.lock

@@ -2787,18 +2787,6 @@ exec-sh@^0.2.0:
   dependencies:
     merge "^1.1.3"
 
-execa@^0.6.3:
-  version "0.6.3"
-  resolved "https://registry.yarnpkg.com/execa/-/execa-0.6.3.tgz#57b69a594f081759c69e5370f0d17b9cb11658fe"
-  dependencies:
-    cross-spawn "^5.0.1"
-    get-stream "^3.0.0"
-    is-stream "^1.1.0"
-    npm-run-path "^2.0.0"
-    p-finally "^1.0.0"
-    signal-exit "^3.0.0"
-    strip-eof "^1.0.0"
-
 execa@^0.7.0:
   version "0.7.0"
   resolved "https://registry.yarnpkg.com/execa/-/execa-0.7.0.tgz#944becd34cc41ee32a63a9faf27ad5a65fc59777"
@@ -3273,10 +3261,6 @@ get-stream@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/get-stream/-/get-stream-3.0.0.tgz#8e943d1358dc37555054ecbe2edb05aa174ede14"
 
-get-them-args@^1.2.1:
-  version "1.3.1"
-  resolved "https://registry.yarnpkg.com/get-them-args/-/get-them-args-1.3.1.tgz#ac1aeca013fda7db12591aaac129c58118e3daa8"
-
 getpass@^0.1.1:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/getpass/-/getpass-0.1.7.tgz#5eff8e3e684d569ae4cb2b1282604e8ba62149fa"
@@ -4576,13 +4560,6 @@ keyboardevents-areequal@^0.2.1:
   version "0.2.2"
   resolved "https://registry.yarnpkg.com/keyboardevents-areequal/-/keyboardevents-areequal-0.2.2.tgz#88191ec738ce9f7591c25e9056de928b40277194"
 
-kill-port@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/kill-port/-/kill-port-1.0.0.tgz#b2c48d3048ea800d6620ff0d4b6f8ce91f644275"
-  dependencies:
-    execa "^0.6.3"
-    get-them-args "^1.2.1"
-
 killable@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/killable/-/killable-1.0.0.tgz#da8b84bd47de5395878f95d64d02f2449fe05e6b"