jprichardsonelectron-mocha
Mocha testing in Electron. This project has two main value propositions:
- You can now test any JavaScript app in a real browser environment.
- You can now test your Electron apps!
Install
npm i -g electron-mochaUsage
Install Electron
First, you need to install Electron. You can either run:
npm i -g electronand then electron will be added to your path. Or, you
can download a version from https://github.com/electron/releases and
then set an environment variable ELECTRON_PATH pointing to the binary.
Note if you're using Mac OS X, the path would be to the actual executable
and not the app directory e.g. /Applications/Electron.app/Contents/MacOS/Electron.
Run Tests
electron-mocha is almost a drop-in replacement for the regular mocha command,
with these additional options:
--renderer Run tests in renderer process [boolean]
--require-main, --main Require module in main process [array]
--script Load module in renderer via script tag [array]
--interactive Show renderer tests in persistent window [boolean]
--url, --index Load custom URL in renderer [string]
--preload Load module during renderer preload [string]
--window-config Supply custom Electron window options [string]
-W, --warnings Print renderer warnings to console [boolean]
--show-window Show the window during tests [booleanThe window-config switch must point to a JSON file or to a JavaScript module that exports
an options object. For more information, check out the
Electron API docs.
For the full list of available options, see electron-mocha --help.
Examples
electron-mochaThis runs all tests in your test directory in the
main process.
electron-mocha --rendererThis runs all tests in your test directory in a
renderer process.
This means that you have access to the entirety of the DOM, web storage, etc. This is because it's actually
running in a Chromium process.
Using for CI
In most Linux CI environments you'll need to use XFVB to run your tests. Either start the appropriate XVFB service or use xvfb-run.
WebGL Tests
If you are writing tests for WebGL programs and you cannot get a WebGL contexts, this may be because the environment doesn't have GPU support. You can pass --ignore-gpu-blacklist to Electron to bypass it:
- command
electron-mocha --main ignore-gpu-blacklist.js - ignore-gpu-blacklist.js
const { app } = require('electron'); app.commandLine.appendSwitch('ignore-gpu-blacklist');
Debugger Support
Use the --inspect or --inspect-brk options to enable Electron's debugger.
When using --renderer this will show the test-runner window dev-tools, including
a debugger (so you do not need to attach a node-inspector).
Note that the window will close automatically when the tests have finished,
therefore this option should be used in combination with debugger statements
anywhere in your tests or code.
Alternatively, you can use the --interactive option which will keep the window
open after your tests have run (you can reload the window to run the tests again),
to give you the opportunity to set breakpoints using the dev-tools inspector.
To debug the main process, you will need to start a node-inspector separately.
Code Coverage
You can use electron-mocha to collect code coverage data in both Electron's
main and renderer processes. To do this, you will need to instrument your code,
run the tests on the instrumented code, and save the coverage stats after all
tests have finished.
For examples, see this thread
License
MIT