Fix zombie processes by hardly terminate them on window close

To be improved: this commits introduce regression on OSX behaviour
when hiding the window: before it was keeping the app opened, and
auto locking it. Now it kills it :D

I honestly think it's worth it regarding the problem zombies process
causes (LOCK on sqlite...).

src/main/app.js

@@ -7,12 +7,17 @@ import { MIN_HEIGHT, MIN_WIDTH } from 'config/constants'
 import menu from 'main/menu'
 import db from 'helpers/db'
 
+import { setMainProcessPID, terminateAllTheThings } from './terminator'
+
+setMainProcessPID(process.pid)
+
 // necessary to prevent win from being garbage collected
 let mainWindow = null
 
 export const getMainWindow = () => mainWindow
 
-let forceClose = false
+// TODO put back OSX close behavior
+// let forceClose = false
 
 const { UPGRADE_EXTENSIONS, ELECTRON_WEBPACK_WDS_PORT, DEV_TOOLS, DEV_TOOLS_MODE } = process.env
 
@@ -27,15 +32,16 @@ const getWindowPosition = (height, width, display = screen.getPrimaryDisplay())
   }
 }
 
-const handleCloseWindow = w => e => {
-  if (!forceClose) {
-    e.preventDefault()
-    w.webContents.send('lock')
-    if (w !== null) {
-      w.hide()
-    }
-  }
-}
+// TODO put back OSX close behavior
+// const handleCloseWindow = w => e => {
+//   if (!forceClose) {
+//     e.preventDefault()
+//     w.webContents.send('lock')
+//     if (w !== null) {
+//       w.hide()
+//     }
+//   }
+// }
 
 const getDefaultUrl = () =>
   __DEV__ ? `http://localhost:${ELECTRON_WEBPACK_WDS_PORT || ''}` : `file://${__dirname}/index.html`
@@ -107,7 +113,9 @@ function createMainWindow() {
 
   window.loadURL(url)
 
-  window.on('close', handleCloseWindow(window))
+  // TODO put back OSX close behavior
+  // window.on('close', handleCloseWindow(window))
+  window.on('close', terminateAllTheThings)
 
   window.on('ready-to-show', () => {
     window.show()
@@ -126,9 +134,10 @@ function createMainWindow() {
   return window
 }
 
-app.on('before-quit', () => {
-  forceClose = true
-})
+// TODO put back OSX close behavior
+// app.on('before-quit', () => {
+//   forceClose = true
+// })
 
 app.on('window-all-closed', () => {
   // On macOS it is common for applications to stay open

src/main/bridge.js

@@ -11,6 +11,7 @@ import sentry from 'sentry/node'
 import user from 'helpers/user'
 
 import setupAutoUpdater, { quitAndInstall } from './autoUpdate'
+import { setInternalProcessPID } from './terminator'
 
 import { getMainWindow } from './app'
 
@@ -49,6 +50,7 @@ const bootInternalProcess = () => {
       SENTRY_USER_ID: userId,
     },
   })
+  setInternalProcessPID(internalProcess.pid)
   internalProcess.on('message', handleGlobalInternalMessage)
   internalProcess.on('exit', handleExit)
 }

src/main/terminator.js

@@ -0,0 +1,32 @@
+// @flow
+
+//                                                       <((((((\\\
+//                                                       /      . }\
+//                                                       ;--..--._|}
+//                                    (\                 '--/\--'  )
+//        DISCLAIMER                   \\                | '-'  :'|
+//        This is a dirty hack          \\               . -==- .-|
+//                                       \\               \.__.'   \--._
+//                                       [\\          __.--|       //  _/'--.
+//                                       \ \\       .'-._ ('-----'/ __/      \
+//                                        \ \\     /   __>|      | '--.       |
+//                                         \ \\   |   \   |     /    /       /
+//                                          \ '\ /     \  |     |  _/       /
+//                                           \  \       \ |     | /        /
+//                                            \  \      \        /
+
+let MAIN_PROCESS_PID: ?number = null
+let INTERNAL_PROCESS_PID: ?number = null
+
+function kill(processType, pid) {
+  console.log(`-> Killing ${processType} process ${pid}`) // eslint-disable-line no-console
+  process.kill(pid, 'SIGTERM')
+}
+
+exports.setMainProcessPID = (pid: number) => (MAIN_PROCESS_PID = pid)
+exports.setInternalProcessPID = (pid: number) => (INTERNAL_PROCESS_PID = pid)
+
+exports.terminateAllTheThings = () => {
+  if (INTERNAL_PROCESS_PID) kill('internal', INTERNAL_PROCESS_PID)
+  if (MAIN_PROCESS_PID) kill('main', MAIN_PROCESS_PID)
+}