Protractor: Tips for better End-to-End Tests

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So last year I shared my initial experiences of getting started with Protractor. Here are some things i’ve learnt since then.

1. Use testSuites

As your Protractor tests grow you are undoubtably going to make use of testSuites. This allows a specific group of tests to be run by passing in the testSuite name into the run parameters.

2. Use only one protractor configuration file

Protractor uses a configuration file which contains various settings for your tests such as baseUrl, tests to run, web driver port etc. When running tests in different places it is tempting to have multiple configuration files. For example a local config and one for your CI server. Avoid this temptation and only have one config file.

3. Manage your Protractor package and dev dependencies

Keeping Protractor up-to-date as well as other packages, such Screenshot Reporter, which you depend upon is really important. If you don’t manage your packages they will quickly become out of date. Luckily using a package.json to store all your packages makes this super easy. You can declare if you want to auto update or use a specific package version when you run npm install.

4. Use a Task Runner such as Gulp

Your protractor tests will just be a small part of your JavaScript eco system. Using a Task runner can help to keep all your tasks in a single place. It also means it’s very simple for anyone in the team to run the Protractor Tests.

5. Learn how to Debug Protractor Tests

My experience is that writing E2E WebDriver tests in Java or C# is a lot easier because the IDE, such as Visual Studio, gives you lots of guidance. As Protractor Tests are JavaScript you get less help so need to understand how to debug. The two main options are browser.pause() and browser.debugger(). Aside from the Protractor debug commands I’d also recommend learning how to use browser development tools such as Chrome Dev tools to help debug JavaScript.

6. Use Protractor for non-angularJs sites only when necessary

Protractor can be used to test non-AngularJS sites but i’d only recommend this when testing a user-flow which jumps out of your AngularJS site, for example page redirects. I would suggest not using this capability to mean you can test non-Angular sites using Protractor.

7. Use other node packages to do stuff

The joy of using Node is that Node Package Manager allows you to do loads of stuff. An example is http-request which you can use to call API’s in your test flow. This is particularly useful if you want to setup some data via a direct API call.

8. Use Page Object Model

Just do it.

9. Multi Thread your Tests

In Protractor it’s so easy to run your tests in parallel and across multiple browsers. Even with a handful of tests you are going to have to look at running tests in parallel for time saving benefits. Running tests in parallel also forces you to have independent tests which is a good way to keep tests maintainable.

10. Handling Cookies and Sessions

Protractor by design does not open/close the browser between specs. This is useful in one way because it speeds up your tests. Closing and Opening browsers between tests has a significant footprint. There are cases though when you need to potentially close a browser to at least clear cookie or session history. In this case you have a couple of options. Firstly WebDriver can interact with cookies or alternatively you can add restartBrowserBetweenTests: true to your protractor config file.

11. Learn AngularJS

Having an understanding of the underlying technology is a huge help in writing good tests. As you’ll probably be using Protractor to tests AngularJS sites then you should definitely learn Angular. Build your own site in Angular and write some tests for it. There are tonnes of great sessions on Pluralsight to help. Learn also how to unit test AngularJS code as this will give you a better appreciation of where to place your test efforts.

12. Use ES6 Generators

At AngularConnect Uri Shaked did a great talk on how to use ES6 generators to control the flow of your Protractor Tests. This is particularly useful if you need certain tasks to occur in a  particular sequence.

13. Understand what Protractor does

Protractor is a wrapper around WebDriver specifically designed for AngularJS apps. This means most of the benefit will come when using AngularJS apps. The two primary benefits i’ve found are:

  • Page synchronisation – As protractor hooks into the angular digest cycle it makes one of the typical problems with E2E tests, When has the page loaded?, problems a lot easier to manage.
  • Angular Specific Locators – by.Binding, by.Model, by.Repater gives you more options for finding stuff on a page.

With this in mind i wouldn’t ever consider using Protractor for a site which isn’t built in AngularJS.

Thats more than enough tips for now.

Enjoy Protractor.

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Using Gulp for Testing

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Last year I shared some posts on testing AngularJS web apps:

Getting started with Protractor to automate E2E tests for AngularJS apps

How to steep a unit test environment for AngularJs Application

I thought i’d start 2016 by sharing some other tips in that area.

What is Gulp?

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Gulp is a JavaScript Task Runner. Now it took me a while to actually get my head around what Gulp actually does. Gulp enables you to encode in JavaScript repetitive tasks that you perform regularly. This could be starting a web server, JavaScript minification or Testing which will be the focus of this blog.

One of the core benefits of Gulp is that it encodes these tasks in a JavaScript file which is typically named gulp.js. This means all of these encoded tasks can be shared across the team and kept in synch using version control.

Another benefit is that gulp utilises the wide variety of packages available via NPM(Node Package Manager) which means you can automate tasks incredibly easily.

In this blog I won’t go through how to setup Gulp from scratch or how to install Node Packages as the official documents do this very well. Instead my focus will be how you can use Gulp to support testing.

If you want to get started from scratch in addition to the official docs i’d highly recommend John Papas Gulp course on Pluralsight – JavaScript Build Automation with GulpJs

Note: if you don’t currently have a Pluralsight account you can get 3 Months FREE by creating a free Visual Studio Dev Essentials account

How to use Gulp for Testing

Gulp can be used for many tasks but in this blog post I’ll focus on tasks that can be used to support testing.

  1. Run Unit Tests

This task runs your JavaScript unit tests using Karma. It utilises your karma configuration file which allows you to configure run parameters, such as single run and also what outputs we want to generate, such as Istanbul Code Coverage reports and jUnit XML. You can read more about configuring your unit tests in my previous post

Using Karma you don’t need to install any additional gulp packages as you can call Karma directly through Gulp as explained here

The gulp task looks as follows:

Snip20160103_2

2. Run Protractor E2E Tests

As detailed in a previous blog post, Protractor, is an E2E testing framework mostly used for AngularJS web apps. This gulp task allows you to execute your protractor tests. You’ll need to make some additional tweaks to the task to allow a test suite to be specified. We use protractor test suites to allow control of what tests are run. To do this we used an NPM package called yargs. This blog helps.

What is cool with this task is that in a single task it will get the latest web driver jar, start a selenium server, run the tests and generate the output.

To run your protractor tests using gulp you’ll need to install a couple of node packages:

Gulp Protractor

Yargs (Used for specifying testSuites)

The gulp task looks as follows:

Snip20160103_3.png

 

3. Linting

Linting is an activity to discover common mistakes in code and is incredibly useful for JavaScript as its not a compiled language. It’s a great example of static testing that can yield great benefits. Here is an example of the output you get:

reporter_problems.png

Using this gulp task you can Lint your code to identify any simple mistakes or errors keeping the code base clean.

To do the linting you need to install the node package JsHint-Stylish

The gulp task looks as follows:

Snip20160103_5

 

Putting it all together

 

To run these tasks you simply start up a nodeJs command prompt and enter gulp followed by your task name. For example:

gulp protractor –testSuiteName

This will run your specified e2e protractor test suite.

As NPM gives you such a wide variety of options there are many more tasks you can add to support your testing. These are probably the three most common. Another example could be starting your mock services.

Local vs CI

You obviously want to avoid duplication so you should use the same Gulp file both locally and on your CI tool such as Jenkins. To achieve this you just need to learn about file paths and ensure your gulp.js file is located sensibly, such as within the project directory.

When running any of the three testing tasks outlined above there is one main difference locally vs CI. Locally you should set Karma and JsLint to watch your files. This provides instant feedback when developing your code. On your CI tool you will want these tasks to execute once, exit and produce the relevant outputs. Executing your gulp tasks through a CI tool such as Jenkins is super easy. In the case of running your Protractor tests the CI job essentially has two commands:

npm install –> Installs your node packages at build time

gulp e2e –testSuiteName –> Executes Protractor tests

You then just need to configure your CI tool to pick up any outputs generated.

Challenges

So this all sounds pretty straightforward but for me it did take a little while to get everything working smoothly. The main challenges I had:

1. What the hell is Gulp!?!?

Sounds simple, but it actually took me a few hours to actually work out the concepts behind Gulp. Hopefully this post has helped clear that up for you.

2. Handling Node Packages Correctly

Gulp in the most part uses node packages to “Do Stuff” so you’ll need to have a good grasp of how that works. Take the time to understand how to use a package.json, devDependencies, npm install and the differences between installing globally v locally. Interestingly, you’ll also need to install gulp both locally and globally.

3. Folder Structres and File Paths

You’ll need to make sure you have your node packages and gulp.js file in a sensible location.The standard is to install dev node packages within the project and your gulp file in the project root. Your gulp file will reference underlying configure files such as karma.conf.js and also declare output directories so you’ll need to understand how to move around the directory structure using JavaScript.

Alternatives

If you keen to crack on and use Gulp, at this point i’d highlight that there are alternatives out there which I haven’t used, the most popular is Grunt.

Finally, a heads up that Gulp 4 is currently in beta and will be launched soon