feat(serve): use chokidar to be able to watch folders (#247)

* feat: use chokidar to be able to watch folders

* fix: prevent multiple restart at the same time

* test: fix commands spec

* fix(serve): main process not rebuilt if changed during build

Author: Akryum

__tests__/commands.spec.js

@@ -9,6 +9,7 @@ const execa = require('execa')
 const portfinder = require('portfinder')
 const Application = require('spectron').Application
 const { chainWebpack, getExternals } = require('../lib/webpackConfig')
+const chokidar = require('chokidar')
 // #endregion
 
 // #region Mocks
@@ -26,6 +27,7 @@ jest.mock('electron-builder/out/cli/install-app-deps.js', () => ({
   installAppDeps: mockInstallAppDeps
 }))
 jest.mock('../lib/webpackConfig.js')
+jest.mock('chokidar')
 const mockPipe = jest.fn()
 const childEvents = {}
 const mockExeca = {
@@ -66,6 +68,11 @@ console.log = jest.fn()
 beforeEach(() => {
   jest.clearAllMocks()
 })
+chokidar.watch.mockImplementation((file) => {
+  return {
+    on: (type, cb) => {}
+  }
+})
 // #endregion
 
 // #region runCommand
@@ -449,9 +456,13 @@ describe('electron:serve', () => {
 
   test('Custom launch arguments is used if provided', async () => {
     let watchCb
-    fs.watchFile.mockImplementation((file, cb) => {
-      // Set callback to be called later
-      watchCb = cb
+    chokidar.watch.mockImplementation((file) => {
+      return {
+        on: (type, cb) => {
+          // Set callback to be called later
+          watchCb = cb
+        }
+      }
     })
     await runCommand('electron:serve', {
       pluginOptions: {
@@ -514,9 +525,13 @@ describe('electron:serve', () => {
     // So we can make sure it wasn't called
     jest.spyOn(process, 'exit')
     let watchCb
-    fs.watchFile.mockImplementation((file, cb) => {
-      // Set callback to be called later
-      watchCb = cb
+    chokidar.watch.mockImplementation((file) => {
+      return {
+        on: (type, cb) => {
+          // Set callback to be called later
+          watchCb = cb
+        }
+      }
     })
     await runCommand('electron:serve', {
       pluginOptions: {
@@ -528,7 +543,7 @@ describe('electron:serve', () => {
     })
 
     // Proper file is watched
-    expect(fs.watchFile.mock.calls[0][0]).toBe('projectPath/customBackground')
+    expect(chokidar.watch.mock.calls[0][0]).toBe('projectPath/customBackground')
     // Child has not yet been killed or unwatched
     expect(mockExeca.send).not.toBeCalled()
     expect(mockExeca.kill).not.toBeCalled()
@@ -560,9 +575,13 @@ describe('electron:serve', () => {
     // So we can make sure it wasn't called
     jest.spyOn(process, 'exit')
     let watchCb = {}
-    fs.watchFile.mockImplementation((file, cb) => {
-      // Set callback to be called later
-      watchCb[file] = cb
+    chokidar.watch.mockImplementation((file) => {
+      return {
+        on: (type, cb) => {
+          // Set callback to be called later
+          watchCb[file] = cb
+        }
+      }
     })
     await runCommand('electron:serve', {
       pluginOptions: {
@@ -576,8 +595,8 @@ describe('electron:serve', () => {
     })
 
     // Proper file is watched
-    expect(fs.watchFile.mock.calls[0][0]).toBe('projectPath/customBackground')
-    expect(fs.watchFile.mock.calls[1][0]).toBe('projectPath/listFile')
+    expect(chokidar.watch.mock.calls[0][0]).toBe('projectPath/customBackground')
+    expect(chokidar.watch.mock.calls[1][0]).toBe('projectPath/listFile')
     // Child has not yet been killed or unwatched
     expect(mockExeca.send).not.toBeCalled()
     expect(mockExeca.kill).not.toBeCalled()

index.js

@@ -298,6 +298,8 @@ module.exports = (api, options) => {
         }
       }
 
+      // Prevent multiple restarts at the same time
+      let queuedBuilds = 0
       // Electron process
       let child
       // Auto restart flag
@@ -328,8 +330,11 @@ module.exports = (api, options) => {
       // Initial start of Electron
       startElectron()
       // Restart on main process file change
+      const chokidar = require('chokidar')
       mainProcessWatch.forEach(file => {
-        fs.watchFile(api.resolve(file), () => {
+        chokidar.watch(api.resolve(file)).on('all', () => {
+          queuedBuilds++
+
           if (args.debug) {
             // Rebuild main process
             startElectron()
@@ -342,8 +347,10 @@ module.exports = (api, options) => {
 
           // Set auto restart flag
           childRestartOnExit = 1
-
-          killElectron()
+          if (child) {
+            // Start Electron if it hasn't been already launched
+            startElectron()
+          }
         })
       })
 
@@ -375,6 +382,12 @@ module.exports = (api, options) => {
       }
 
       function launchElectron () {
+        // Kill existing instances
+        killElectron()
+        // Don't launch if a new background file is being bundled
+        queuedBuilds--
+        if (queuedBuilds > 0) return
+
         if (args.debug) {
           //   Do not launch electron and provide instructions on launching through debugger
           info(
@@ -404,9 +417,6 @@ module.exports = (api, options) => {
             info('Launching Electron...')
           }
 
-          // Disable Electron process auto restart
-          childRestartOnExit = 0
-
           let stdioConfig = [null, null, null]
 
           // Use an IPC on Windows for graceful exit
@@ -448,15 +458,18 @@ module.exports = (api, options) => {
           }
 
           child.on('exit', () => {
-            child = null
+            if (child.killed) {
+              child = null
+            }
 
             if (childExitTimeout) {
               clearTimeout(childExitTimeout)
               childExitTimeout = null
             }
 
             if (childRestartOnExit > 0) {
-              startElectron()
+              // Disable Electron process auto restart
+              childRestartOnExit = 0
             } else {
               process.exit(0)
             }

package.json

@@ -28,6 +28,7 @@
   "license": "MIT",
   "private": false,
   "dependencies": {
+    "chokidar": "^2.1.5",
     "electron-builder": "^20.29.0",
     "execa": "^1.0.0",
     "friendly-errors-webpack-plugin": "^1.7.0",

yarn.lock

@@ -4096,6 +4096,25 @@ chokidar@^2.0.0, chokidar@^2.0.2, chokidar@^2.0.3, chokidar@^2.0.4, chokidar@^2.
   optionalDependencies:
     fsevents "^1.2.7"
 
+chokidar@^2.1.5:
+  version "2.1.5"
+  resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.1.5.tgz#0ae8434d962281a5f56c72869e79cb6d9d86ad4d"
+  integrity sha512-i0TprVWp+Kj4WRPtInjexJ8Q+BqTE909VpH8xVhXrJkoc5QC8VO9TryGOqTr+2hljzc1sC62t22h5tZePodM/A==
+  dependencies:
+    anymatch "^2.0.0"
+    async-each "^1.0.1"
+    braces "^2.3.2"
+    glob-parent "^3.1.0"
+    inherits "^2.0.3"
+    is-binary-path "^1.0.0"
+    is-glob "^4.0.0"
+    normalize-path "^3.0.0"
+    path-is-absolute "^1.0.0"
+    readdirp "^2.2.1"
+    upath "^1.1.1"
+  optionalDependencies:
+    fsevents "^1.2.7"
+
 chownr@^1.0.1, chownr@^1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/chownr/-/chownr-1.1.1.tgz#54726b8b8fff4df053c42187e801fb4412df1494"
@@ -14255,7 +14274,7 @@ unzip-response@^2.0.1:
   resolved "https://registry.yarnpkg.com/unzip-response/-/unzip-response-2.0.1.tgz#d2f0f737d16b0615e72a6935ed04214572d56f97"
   integrity sha1-0vD3N9FrBhXnKmk17QQhRXLVb5c=
 
-upath@^1.1.0:
+upath@^1.1.0, upath@^1.1.1:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/upath/-/upath-1.1.2.tgz#3db658600edaeeccbe6db5e684d67ee8c2acd068"
   integrity sha512-kXpym8nmDmlCBr7nKdIx8P2jNBa+pBpIUFRnKJ4dr8htyYGJFokkr2ZvERRtUN+9SY+JqXouNgUPtv6JQva/2Q==