Mock Native API in your E2E test

ElectronMeetup in Tokyo LT (https://connpass.com/event/69473/)

How to run spectron E2E test in case of using Native API in your specs.

Transcript

1. Mock Native API in your E2E test 2017/11/06 ElectronMeetup in Tokyo LT @joe_re
2. Who am I? twitter: @joe_re github: @joe­re community: Nishinippori.rb, GraphQL Tokyo Organizer
3. Book
4. Applications CafePitch Markdown Driven PresentationTool Tubutler Simple and usefull Youtube player
5. Today, I talk about spectron E2E test in case of using 'Native API' in your spec.
6. Spectron
7. What is Spectron? E2E Testing tool for Electron appplication. You can call ElectronAPI in your spec via ChromeDriver and WebDriver.io.
8. Example const app = new spectron.Application({ path: 'path/to/your/app' }); describe('application launch', function () { this.timeout(10000); beforeEach(function () { return app.start(); }); afterEach(function () { return app.stop(); }); it('shows an initial window', function () { return app.client.getWindowCount().then(function (count) { assert.equal(count, 1); }); }); });
9. Strong Points You can access any DOM via Webdriver.io. You can call any Electron API in your spec. No need setup script.(use Chromium inside Electron) Support CI services.(Travis, AppVeyor, etc)
10. DEMO
11. Spectron is nice. But it can't access Native API. (latest v3.7.2) So it can't mock Menu, Dialog, etc modules... https://github.com/electron/spectron/issues/94
12. This is simple solution, but ugly... if (process.env.NODE_ENV === "production") { // production code here } else { // test code here }
13. I want to write a spec which doesn't affect production code.
14. I created two modules to resolve it. spectron­fake­menu https://github.com/joe­re/spectron­fake­menu spectron­fake­dialog https://github.com/joe­re/spectron­fake­dialog
15. Usage spectron­fake­menu const Application = require('spectron').Application; const fakeMenu = require('spectron-fake-menu'); const app = new Application({ path: electron, args: [ path.join(__dirname, '.') ] }); fakeMenu.apply(app); // apply fake menu await app.start(); fakeMenu.clickMenu('Config'); // 'Config' Menu click fakeMenu.clickMenu('File', 'CloseTab'); // File->CloseTab Menu click spectron­fake­dialog const Application = require('spectron').Application; const fakeDialog = require('spectron-fake-dialog'); const app = new Application({ path: electron, args: [ path.join(__dirname, '.') ] }); fakeDialog.apply(app); await app.start(); fakeDialog.mock([ { method: 'showOpenDialog', value: ['faked.txt'] } ])); // write your specs
16. How do they work? Electron provides '­­require' option same as Node.js. It can preload a module before run main script. These modules inject extra IPC and provide API which call or mock Native API inside your specs.
17. Rough image
18. Implementation(spectron­fake­dialog) const path = require('path'); let _app = null; function apply(app) { _app = app; _app.args.unshift(path.join(__dirname, 'preload.js')); _app.args.unshift('--require'); return _app; } function mock(options) { return _app.electron.ipcRenderer.sendSync('SPECTRON_FAKE_DIALOG/SEND', options); } module.exports = { apply, mock };
19. Implementation(spectron­fake­dialog) preload script const { dialog, ipcMain, BrowserWindow } = require('electron'); //... some logics for creating mocked function ... function fake(options) { options.forEach(v => { if (dialog[v.method]) { dialog[v.method] = mockFunction.bind(null, v.value); } else { throw new Error(`can't find ${v.method} on dialog module.`); } }); } ipcMain.on('SPECTRON_FAKE_DIALOG/SEND', (e, options) => { fake(options); e.returnValue = true; });
20. Please use they if you'd like.
21. Thank you for your attention!