This post is here to help you get started.
For this post, we are going to create a Todo Application, using vanilla JS so that we can test everything.
The final app demo is here : http://b2l.github.io/todo-app/html/todo.html
And the application code is here : https://github.com/b2l/todo-app
Before we get started, let's create the project directory and jump into it :
mkdir todo-app cd todo-app
This project is really basic, so we won’t set up any assets compilation.
We will just have an html entry point that will load any file we need.
We will use the following libraries to test the application :
- Mocha (test framework)
- ChaiJs (assertion library)
- selenium webdriver (from the selenium website: "Selenium automates browsers. That's it!")
Let's install them :
npm install -D mocha chai selenium-webdriver
Mocha provide a Command Line Interface that makes it easier to launch tests, so install it:
npm install -g mocha
Selenium work by having a java application that control the browser. You, as a client, connect to this web server and send it some command.
To use selenium, we need the selenium java server. Download it from here : selenium standalone server
We will need the path to the jar file you just downloaded.
Let’s create a structure for this.
mkdir html mkdir css mkdir js mkdir tests
Let's create our first test.
Our todo application will manage a list of todos. So we want to be able to :
- create a todo
- get a todo
- get all todos
- update a todo
- remove a todo
- mark a todo as done
- mark a todo as not done
Here is a part of our test file :
Before looking at the implementation, let's run the test :
Ok mocha complains that the file ../js/Todos.js doesn't exist. Let's create it now :
Run tests again :
And we are done !
The test workflow with selenium is as follow :
- Run the selenium server
- Create a client with options
- Execute command
Everything is a command, or an action, from asking selenium for a node matching a selector to clicking somewhere or closing the browser.
The first point can be achieved in different ways, either by a script which manages the server, or we can start / stop it from the test.
We will use the second option, here is the file to initialize the server :
I won't go through the todo-application implementation because it's not the point of this article.
If you want to follow this step by step, just copy the css, html and js directories. Run our application :
python -m SimpleHTTPServer
You can test your application here : http://localhost:8000/html/todo.html
Here is the interface test :
To run the interface test, we can use the same command as before :
Before we run the test: if you are a user of tmux (screen should have the same issue), please note that you will have to attach the selenium server to the user space as describe here : http://borkweb.com/story/chromedriver-doesnt-run-in-tmux
You can see a chrome browser starting in background and interacting with our application. Awesome !
There you are ! We have extracted and tested the domain part of the application (the Todos model) and we have test that the interface work properly too. You now have a small setup for testing your frontend application.