electron/spec/api-browser-window-spec.js

'use strict'

const assert = require('assert')
const fs = require('fs')
const path = require('path')
const os = require('os')
const http = require('http')

const remote = require('electron').remote
const screen = require('electron').screen

const app = remote.require('electron').app
const ipcMain = remote.require('electron').ipcMain
const ipcRenderer = require('electron').ipcRenderer
const BrowserWindow = remote.require('electron').BrowserWindow

const isCI = remote.getGlobal('isCi')

describe('browser-window module', function () {
  var fixtures = path.resolve(__dirname, 'fixtures')
  var w = null
  var server

  before(function (done) {
    server = http.createServer(function (req, res) {
      function respond() { res.end(''); }
      setTimeout(respond, req.url.includes('slow') ? 200 : 0)
    });
    server.listen(0, '127.0.0.1', function () {
      server.url = 'http://127.0.0.1:' + server.address().port
      done()
    })
  })

  after(function () {
    server.close()
    server = null
  })

  beforeEach(function () {
    if (w != null) {
      w.destroy()
    }
    w = new BrowserWindow({
      show: false,
      width: 400,
      height: 400
    })
  })

  afterEach(function () {
    if (w != null) {
      w.destroy()
    }
    w = null
  })

  describe('BrowserWindow.close()', function () {
    it('should emit unload handler', function (done) {
      w.webContents.on('did-finish-load', function () {
        w.close()
      })
      w.on('closed', function () {
        var test = path.join(fixtures, 'api', 'unload')
        var content = fs.readFileSync(test)
        fs.unlinkSync(test)
        assert.equal(String(content), 'unload')
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'unload.html'))
    })

    it('should emit beforeunload handler', function (done) {
      w.on('onbeforeunload', function () {
        done()
      })
      w.webContents.on('did-finish-load', function () {
        w.close()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'beforeunload-false.html'))
    })
  })

  describe('window.close()', function () {
    it('should emit unload handler', function (done) {
      w.on('closed', function () {
        var test = path.join(fixtures, 'api', 'close')
        var content = fs.readFileSync(test)
        fs.unlinkSync(test)
        assert.equal(String(content), 'close')
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'close.html'))
    })

    it('should emit beforeunload handler', function (done) {
      w.on('onbeforeunload', function () {
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'close-beforeunload-false.html'))
    })
  })

  describe('BrowserWindow.destroy()', function () {
    it('prevents users to access methods of webContents', function () {
      var webContents = w.webContents
      w.destroy()
      assert.throws(function () {
        webContents.getId()
      }, /Object has been destroyed/)
    })
  })

  describe('BrowserWindow.loadURL(url)', function () {
    it('should emit did-start-loading event', function (done) {
      w.webContents.on('did-start-loading', function () {
        done()
      })
      w.loadURL('about:blank')
    })

    it('should emit did-get-response-details event', function (done) {
      // expected {fileName: resourceType} pairs
      var expectedResources = {
        'did-get-response-details.html': 'mainFrame',
        'logo.png': 'image'
      }
      var responses = 0;
      w.webContents.on('did-get-response-details', function (event, status, newUrl, oldUrl, responseCode, method, referrer, headers, resourceType) {
        responses++
        var fileName = newUrl.slice(newUrl.lastIndexOf('/') + 1)
        var expectedType = expectedResources[fileName]
        assert(!!expectedType, `Unexpected response details for ${newUrl}`)
        assert(typeof status === 'boolean', 'status should be boolean')
        assert.equal(responseCode, 200)
        assert.equal(method, 'GET')
        assert(typeof referrer === 'string', 'referrer should be string')
        assert(!!headers, 'headers should be present')
        assert(typeof headers === 'object', 'headers should be object')
        assert.equal(resourceType, expectedType, 'Incorrect resourceType')
        if (responses === Object.keys(expectedResources).length) {
          done()
        }
      })
      w.loadURL('file://' + path.join(fixtures, 'pages', 'did-get-response-details.html'))
    })

    it('should emit did-fail-load event for files that do not exist', function (done) {
      w.webContents.on('did-fail-load', function (event, code, desc, url, isMainFrame) {
        assert.equal(code, -6)
        assert.equal(desc, 'ERR_FILE_NOT_FOUND')
        assert.equal(isMainFrame, true)
        done()
      })
      w.loadURL('file://a.txt')
    })

    it('should emit did-fail-load event for invalid URL', function (done) {
      w.webContents.on('did-fail-load', function (event, code, desc, url, isMainFrame) {
        assert.equal(desc, 'ERR_INVALID_URL')
        assert.equal(code, -300)
        assert.equal(isMainFrame, true)
        done()
      })
      w.loadURL('http://example:port')
    })

    it('should set `mainFrame = false` on did-fail-load events in iframes', function (done) {
      w.webContents.on('did-fail-load', function (event, code, desc, url, isMainFrame) {
        assert.equal(isMainFrame, false)
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'did-fail-load-iframe.html'))
    })

    it('does not crash in did-fail-provisional-load handler', function (done) {
      this.timeout(10000)
      w.webContents.once('did-fail-provisional-load', function () {
        w.loadURL('http://127.0.0.1:11111')
        done()
      })
      w.loadURL('http://127.0.0.1:11111')
    })
  })

  describe('BrowserWindow.show()', function () {
    if (isCI) {
      return
    }

    it('should focus on window', function () {
      w.show()
      assert(w.isFocused())
    })

    it('should make the window visible', function () {
      w.show()
      assert(w.isVisible())
    })

    it('emits when window is shown', function (done) {
      this.timeout(10000)
      w.once('show', function () {
        assert.equal(w.isVisible(), true)
        done()
      })
      w.show()
    })
  })

  describe('BrowserWindow.hide()', function () {
    if (isCI) {
      return
    }

    it('should defocus on window', function () {
      w.hide()
      assert(!w.isFocused())
    })

    it('should make the window not visible', function () {
      w.show()
      w.hide()
      assert(!w.isVisible())
    })

    it('emits when window is hidden', function (done) {
      this.timeout(10000)
      w.show()
      w.once('hide', function () {
        assert.equal(w.isVisible(), false)
        done()
      })
      w.hide()
    })
  })

  describe('BrowserWindow.showInactive()', function () {
    it('should not focus on window', function () {
      w.showInactive()
      assert(!w.isFocused())
    })
  })

  describe('BrowserWindow.focus()', function () {
    it('does not make the window become visible', function () {
      assert.equal(w.isVisible(), false)
      w.focus()
      assert.equal(w.isVisible(), false)
    })
  })

  describe('BrowserWindow.blur()', function () {
    it('removes focus from window', function () {
      w.blur()
      assert(!w.isFocused())
    })
  })

  describe('BrowserWindow.capturePage(rect, callback)', function () {
    it('calls the callback with a Buffer', function (done) {
      w.capturePage({
        x: 0,
        y: 0,
        width: 100,
        height: 100
      }, function (image) {
        assert.equal(image.isEmpty(), true)
        done()
      })
    })
  })

  describe('BrowserWindow.setSize(width, height)', function () {
    it('sets the window size', function (done) {
      var size = [300, 400]
      w.once('resize', function () {
        var newSize = w.getSize()
        assert.equal(newSize[0], size[0])
        assert.equal(newSize[1], size[1])
        done()
      })
      w.setSize(size[0], size[1])
    })
  })

  describe('BrowserWindow.setPosition(x, y)', function () {
    it('sets the window position', function (done) {
      var pos = [10, 10]
      w.once('move', function () {
        var newPos = w.getPosition()
        assert.equal(newPos[0], pos[0])
        assert.equal(newPos[1], pos[1])
        done()
      })
      w.setPosition(pos[0], pos[1])
    })
  })

  describe('BrowserWindow.setContentSize(width, height)', function () {
    it('sets the content size', function () {
      var size = [400, 400]
      w.setContentSize(size[0], size[1])
      var after = w.getContentSize()
      assert.equal(after[0], size[0])
      assert.equal(after[1], size[1])
    })

    it('works for framless window', function () {
      w.destroy()
      w = new BrowserWindow({
        show: false,
        frame: false,
        width: 400,
        height: 400
      })
      var size = [400, 400]
      w.setContentSize(size[0], size[1])
      var after = w.getContentSize()
      assert.equal(after[0], size[0])
      assert.equal(after[1], size[1])
    })
  })

  describe('BrowserWindow.fromId(id)', function () {
    it('returns the window with id', function () {
      assert.equal(w.id, BrowserWindow.fromId(w.id).id)
    })
  })

  describe('"useContentSize" option', function () {
    it('make window created with content size when used', function () {
      w.destroy()
      w = new BrowserWindow({
        show: false,
        width: 400,
        height: 400,
        useContentSize: true
      })
      var contentSize = w.getContentSize()
      assert.equal(contentSize[0], 400)
      assert.equal(contentSize[1], 400)
    })

    it('make window created with window size when not used', function () {
      var size = w.getSize()
      assert.equal(size[0], 400)
      assert.equal(size[1], 400)
    })

    it('works for framless window', function () {
      w.destroy()
      w = new BrowserWindow({
        show: false,
        frame: false,
        width: 400,
        height: 400,
        useContentSize: true
      })
      var contentSize = w.getContentSize()
      assert.equal(contentSize[0], 400)
      assert.equal(contentSize[1], 400)
      var size = w.getSize()
      assert.equal(size[0], 400)
      assert.equal(size[1], 400)
    })
  })

  describe('"title-bar-style" option', function () {
    if (process.platform !== 'darwin') {
      return
    }
    if (parseInt(os.release().split('.')[0]) < 14) {
      return
    }

    it('creates browser window with hidden title bar', function () {
      w.destroy()
      w = new BrowserWindow({
        show: false,
        width: 400,
        height: 400,
        titleBarStyle: 'hidden'
      })
      var contentSize = w.getContentSize()
      assert.equal(contentSize[1], 400)
    })

    it('creates browser window with hidden inset title bar', function () {
      w.destroy()
      w = new BrowserWindow({
        show: false,
        width: 400,
        height: 400,
        titleBarStyle: 'hidden-inset'
      })
      var contentSize = w.getContentSize()
      assert.equal(contentSize[1], 400)
    })
  })

  describe('"enableLargerThanScreen" option', function () {
    if (process.platform === 'linux') {
      return
    }

    beforeEach(function () {
      w.destroy()
      w = new BrowserWindow({
        show: true,
        width: 400,
        height: 400,
        enableLargerThanScreen: true
      })
    })

    it('can move the window out of screen', function () {
      w.setPosition(-10, -10)
      var after = w.getPosition()
      assert.equal(after[0], -10)
      assert.equal(after[1], -10)
    })

    it('can set the window larger than screen', function () {
      var size = screen.getPrimaryDisplay().size
      size.width += 100
      size.height += 100
      w.setSize(size.width, size.height)
      var after = w.getSize()
      assert.equal(after[0], size.width)
      assert.equal(after[1], size.height)
    })
  })

  describe('"web-preferences" option', function () {
    afterEach(function () {
      ipcMain.removeAllListeners('answer')
    })

    describe('"preload" option', function () {
      it('loads the script before other scripts in window', function (done) {
        var preload = path.join(fixtures, 'module', 'set-global.js')
        ipcMain.once('answer', function (event, test) {
          assert.equal(test, 'preload')
          done()
        })
        w.destroy()
        w = new BrowserWindow({
          show: false,
          webPreferences: {
            preload: preload
          }
        })
        w.loadURL('file://' + path.join(fixtures, 'api', 'preload.html'))
      })
    })

    describe('"node-integration" option', function () {
      it('disables node integration when specified to false', function (done) {
        var preload = path.join(fixtures, 'module', 'send-later.js')
        ipcMain.once('answer', function (event, test) {
          assert.equal(test, 'undefined')
          done()
        })
        w.destroy()
        w = new BrowserWindow({
          show: false,
          webPreferences: {
            preload: preload,
            nodeIntegration: false
          }
        })
        w.loadURL('file://' + path.join(fixtures, 'api', 'blank.html'))
      })
    })
  })

  describe('beforeunload handler', function () {
    it('returning true would not prevent close', function (done) {
      w.on('closed', function () {
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'close-beforeunload-true.html'))
    })

    it('returning non-empty string would not prevent close', function (done) {
      w.on('closed', function () {
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'close-beforeunload-string.html'))
    })

    it('returning false would prevent close', function (done) {
      w.on('onbeforeunload', function () {
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'close-beforeunload-false.html'))
    })

    it('returning empty string would prevent close', function (done) {
      w.on('onbeforeunload', function () {
        done()
      })
      w.loadURL('file://' + path.join(fixtures, 'api', 'close-beforeunload-empty-string.html'))
    })
  })

  describe('new-window event', function () {
    if (isCI && process.platform === 'darwin') {
      return
    }

    it('emits when window.open is called', function (done) {
      w.webContents.once('new-window', function (e, url, frameName) {
        e.preventDefault()
        assert.equal(url, 'http://host/')
        assert.equal(frameName, 'host')
        done()
      })
      w.loadURL('file://' + fixtures + '/pages/window-open.html')
    })

    it('emits when link with target is called', function (done) {
      this.timeout(10000)
      w.webContents.once('new-window', function (e, url, frameName) {
        e.preventDefault()
        assert.equal(url, 'http://host/')
        assert.equal(frameName, 'target')
        done()
      })
      w.loadURL('file://' + fixtures + '/pages/target-name.html')
    })
  })

  describe('maximize event', function () {
    if (isCI) {
      return
    }

    it('emits when window is maximized', function (done) {
      this.timeout(10000)
      w.once('maximize', function () {
        done()
      })
      w.show()
      w.maximize()
    })
  })

  describe('unmaximize event', function () {
    if (isCI) {
      return
    }

    it('emits when window is unmaximized', function (done) {
      this.timeout(10000)
      w.once('unmaximize', function () {
        done()
      })
      w.show()
      w.maximize()
      w.unmaximize()
    })
  })

  describe('minimize event', function () {
    if (isCI) {
      return
    }

    it('emits when window is minimized', function (done) {
      this.timeout(10000)
      w.once('minimize', function () {
        done()
      })
      w.show()
      w.minimize()
    })
  })

  describe('beginFrameSubscription method', function () {
    this.timeout(20000)

    it('subscribes frame updates', function (done) {
      let called = false
      w.loadURL('file://' + fixtures + '/api/blank.html')
      w.webContents.beginFrameSubscription(function (data) {
        // This callback might be called twice.
        if (called) return
        called = true

        assert.notEqual(data.length, 0)
        w.webContents.endFrameSubscription()
        done()
      })
    })
  })

  describe('savePage method', function () {
    const savePageDir = path.join(fixtures, 'save_page')
    const savePageHtmlPath = path.join(savePageDir, 'save_page.html')
    const savePageJsPath = path.join(savePageDir, 'save_page_files', 'test.js')
    const savePageCssPath = path.join(savePageDir, 'save_page_files', 'test.css')

    after(function () {
      try {
        fs.unlinkSync(savePageCssPath)
        fs.unlinkSync(savePageJsPath)
        fs.unlinkSync(savePageHtmlPath)
        fs.rmdirSync(path.join(savePageDir, 'save_page_files'))
        fs.rmdirSync(savePageDir)
      } catch (e) {
        // Ignore error
      }
    })

    it('should save page to disk', function (done) {
      w.webContents.on('did-finish-load', function () {
        w.webContents.savePage(savePageHtmlPath, 'HTMLComplete', function (error) {
          assert.equal(error, null)
          assert(fs.existsSync(savePageHtmlPath))
          assert(fs.existsSync(savePageJsPath))
          assert(fs.existsSync(savePageCssPath))
          done()
        })
      })
      w.loadURL('file://' + fixtures + '/pages/save_page/index.html')
    })
  })

  describe('BrowserWindow options argument is optional', function () {
    it('should create a window with default size (800x600)', function () {
      w.destroy()
      w = new BrowserWindow()
      var size = w.getSize()
      assert.equal(size[0], 800)
      assert.equal(size[1], 600)
    })
  })

  describe('window states', function () {
    describe('resizable state', function () {
      it('can be changed with resizable option', function () {
        w.destroy()
        w = new BrowserWindow({show: false, resizable: false})
        assert.equal(w.isResizable(), false)
      })

      it('can be changed with setResizable method', function () {
        assert.equal(w.isResizable(), true)
        w.setResizable(false)
        assert.equal(w.isResizable(), false)
        w.setResizable(true)
        assert.equal(w.isResizable(), true)
      })
    })

    describe('loading main frame state', function () {
      it('is true when the main frame is loading', function (done) {
        w.webContents.on('did-start-loading', function() {
          assert.equal(w.webContents.isLoadingMainFrame(), true)
          done()
        })
        w.webContents.loadURL(server.url)
      })

      it('is false when only a subframe is loading', function (done) {
        w.webContents.once('did-finish-load', function() {
          assert.equal(w.webContents.isLoadingMainFrame(), false)
          w.webContents.on('did-start-loading', function() {
            assert.equal(w.webContents.isLoadingMainFrame(), false)
            done()
          })
          w.webContents.executeJavaScript(`
            var iframe = document.createElement('iframe')
            iframe.src = '${server.url}/page2'
            document.body.appendChild(iframe)
          `)
        })
        w.webContents.loadURL(server.url)
      })

      it('is true when navigating to pages from the same origin', function (done) {
        w.webContents.once('did-finish-load', function() {
          assert.equal(w.webContents.isLoadingMainFrame(), false)
          w.webContents.on('did-start-loading', function() {
            assert.equal(w.webContents.isLoadingMainFrame(), true)
            done()
          })
          w.webContents.loadURL(`${server.url}/page2`)
        })
        w.webContents.loadURL(server.url)
      })
    })
  })

  describe('window states (excluding Linux)', function () {
    // Not implemented on Linux.
    if (process.platform === 'linux') return

    describe('movable state', function () {
      it('can be changed with movable option', function () {
        w.destroy()
        w = new BrowserWindow({show: false, movable: false})
        assert.equal(w.isMovable(), false)
      })

      it('can be changed with setMovable method', function () {
        assert.equal(w.isMovable(), true)
        w.setMovable(false)
        assert.equal(w.isMovable(), false)
        w.setMovable(true)
        assert.equal(w.isMovable(), true)
      })
    })

    describe('minimizable state', function () {
      it('can be changed with minimizable option', function () {
        w.destroy()
        w = new BrowserWindow({show: false, minimizable: false})
        assert.equal(w.isMinimizable(), false)
      })

      it('can be changed with setMinimizable method', function () {
        assert.equal(w.isMinimizable(), true)
        w.setMinimizable(false)
        assert.equal(w.isMinimizable(), false)
        w.setMinimizable(true)
        assert.equal(w.isMinimizable(), true)
      })
    })

    describe('maximizable state', function () {
      it('can be changed with maximizable option', function () {
        w.destroy()
        w = new BrowserWindow({show: false, maximizable: false})
        assert.equal(w.isMaximizable(), false)
      })

      it('can be changed with setMaximizable method', function () {
        assert.equal(w.isMaximizable(), true)
        w.setMaximizable(false)
        assert.equal(w.isMaximizable(), false)
        w.setMaximizable(true)
        assert.equal(w.isMaximizable(), true)
      })

      it('is not affected when changing other states', function () {
        w.setMaximizable(false)
        assert.equal(w.isMaximizable(), false)
        w.setMinimizable(false)
        assert.equal(w.isMaximizable(), false)
        w.setClosable(false)
        assert.equal(w.isMaximizable(), false)
      })
    })

    describe('fullscreenable state', function () {
      // Only implemented on OS X.
      if (process.platform !== 'darwin') return

      it('can be changed with fullscreenable option', function () {
        w.destroy()
        w = new BrowserWindow({show: false, fullscreenable: false})
        assert.equal(w.isFullScreenable(), false)
      })

      it('can be changed with setFullScreenable method', function () {
        assert.equal(w.isFullScreenable(), true)
        w.setFullScreenable(false)
        assert.equal(w.isFullScreenable(), false)
        w.setFullScreenable(true)
        assert.equal(w.isFullScreenable(), true)
      })
    })

    describe('closable state', function () {
      it('can be changed with closable option', function () {
        w.destroy()
        w = new BrowserWindow({show: false, closable: false})
        assert.equal(w.isClosable(), false)
      })

      it('can be changed with setClosable method', function () {
        assert.equal(w.isClosable(), true)
        w.setClosable(false)
        assert.equal(w.isClosable(), false)
        w.setClosable(true)
        assert.equal(w.isClosable(), true)
      })
    })

    describe('hasShadow state', function () {
      // On Window there is no shadow by default and it can not be changed
      // dynamically.
      it('can be changed with hasShadow option', function () {
        w.destroy()
        let hasShadow = process.platform !== 'darwin'
        w = new BrowserWindow({show: false, hasShadow: hasShadow})
        assert.equal(w.hasShadow(), hasShadow)
      })

      it('can be changed with setHasShadow method', function () {
        if (process.platform !== 'darwin') return

        assert.equal(w.hasShadow(), true)
        w.setHasShadow(false)
        assert.equal(w.hasShadow(), false)
        w.setHasShadow(true)
        assert.equal(w.hasShadow(), true)
      })
    })
  })

  describe('window.webContents.send(channel, args...)', function () {
    it('throws an error when the channel is missing', function () {
      assert.throws(function () {
        w.webContents.send()
      }, 'Missing required channel argument')

      assert.throws(function () {
        w.webContents.send(null)
      }, 'Missing required channel argument')
    })
  })

  describe('dev tool extensions', function () {
    describe('BrowserWindow.addDevToolsExtension', function () {
      this.timeout(10000)

      beforeEach(function () {
        BrowserWindow.removeDevToolsExtension('foo')

        var extensionPath = path.join(__dirname, 'fixtures', 'devtools-extensions', 'foo')
        BrowserWindow.addDevToolsExtension(extensionPath)

        w.webContents.on('devtools-opened', function () {
          var showPanelIntevalId = setInterval(function () {
            if (w && w.devToolsWebContents) {
              w.devToolsWebContents.executeJavaScript('(' + (function () {
                var lastPanelId = WebInspector.inspectorView._tabbedPane._tabs.peekLast().id
                WebInspector.inspectorView.showPanel(lastPanelId)
              }).toString() + ')()')
            } else {
              clearInterval(showPanelIntevalId)
            }
          }, 100)
        })

        w.loadURL('about:blank')
      })

      describe('when the devtools is docked', function () {
        it('creates the extension', function (done) {
          w.webContents.openDevTools({mode: 'bottom'})

          ipcMain.once('answer', function (event, message) {
            assert.equal(message, 'extension loaded')
            done()
          })
        })
      })

      describe('when the devtools is undocked', function () {
        it('creates the extension', function (done) {
          w.webContents.openDevTools({mode: 'undocked'})

          ipcMain.once('answer', function (event, message) {
            assert.equal(message, 'extension loaded')
            done()
          })
        })
      })
    })

    it('serializes the registered extensions on quit', function () {
      var extensionName = 'foo'
      var extensionPath = path.join(__dirname, 'fixtures', 'devtools-extensions', extensionName)
      var serializedPath = path.join(app.getPath('userData'), 'DevTools Extensions')

      BrowserWindow.addDevToolsExtension(extensionPath)
      app.emit('will-quit')
      assert.deepEqual(JSON.parse(fs.readFileSync(serializedPath)), [extensionPath])

      BrowserWindow.removeDevToolsExtension(extensionName)
      app.emit('will-quit')
      assert.equal(fs.existsSync(serializedPath), false)
    })
  })

  describe('window.webContents.executeJavaScript', function () {
    var expected = 'hello, world!'
    var code = '(() => "' + expected + '")()'

    it('doesnt throw when no calback is provided', function () {
      const result = ipcRenderer.sendSync('executeJavaScript', code, false)
      assert.equal(result, 'success')
    })

    it('returns result when calback is provided', function (done) {
      ipcRenderer.send('executeJavaScript', code, true)
      ipcRenderer.once('executeJavaScript-response', function (event, result) {
        assert.equal(result, expected)
        done()
      })
    })

    it('works after page load and during subframe load', function (done) {
      w.webContents.once('did-finish-load', function() {
        // initiate a sub-frame load, then try and execute script during it
        w.webContents.executeJavaScript(`
          var iframe = document.createElement('iframe')
          iframe.src = '${server.url}/slow'
          document.body.appendChild(iframe)
        `, function() {
          w.webContents.executeJavaScript(`console.log('hello')`, function() {
            done()
          })
        })
      })
      w.loadURL(server.url)
    })

    it('executes after page load', function (done) {
      w.webContents.executeJavaScript(code, function(result) {
        assert.equal(result, expected)
        done()
      })
      w.loadURL(server.url)
    })
  })
})