Using Gulp for Testing

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?

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:

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:

 

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:

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:

 

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

Pedestrian Crossings, Continuous Integration and Culture

You have just arrived into a new country, checked into your hotel and ready to head out exploring the area. Soon after leaving the hotel you will face your first challenge; the Pedestrian Crossing.

I’ve been lucky to visit a few different countries and not so lucky to experience some of the world’s wildest Pedestrian Crossings (Could make a great TV Show!). I live in the UK where Pedestrian Crossings are, at least to me, well signposted and generally observed both by pedestrians and drivers(with exceptions).Across the rest of Europe you’ll find experiences, in particular Italy. My strategy when i visit; Step out onto the pedestrian crossing, hope the driver notices you and stops, if he doesn’t get ready to run! Seems like i’m not alone! Other parts of the world such as India, Thailand, Vietnam introduce other examples of even riskier behaviour to cross the street.

Japan is one of the most fascinating countries i’ve visited. Incredible cities, beautiful countryside and very obedient pedestrians. Late one night, at around 3am, i was returning to my hotel. The roads were empty and not a vehicle in sight. Regardless to the apparent lack of danger, if the “Wait” sign was shown, pedestrians did not cross.

Pedestrian Crossings and Culture

As you travel the world you realise culture has a huge impact on pedestrian behaviour. An international research team did a study into the impact of Culture; Different risk thresholds in pedestrian road crossing behaviour: A comparison of French and Japanese approaches.

“The group set up observations posts at various crossings in the French city of Strasbourg and the Japanese city of Inuyama. The results were both clear and striking. At the legal crossing in Strasbourg, France, about 67 percent of pedestrians crossed against the red light. Only 7 percent of walkers in Inuyama did the same. At the unmarked crossing, the researchers measured how much time between cars a pedestrian needed before deciding to walk. In Strasbourg that time clocked in at 9 seconds, on average; in Inuyama, walkers felt free from risk at 16-second gaps.”

These findings match my anecdotal experience across Europe and in Japan.

Continuous Integration

After reflecting on a near death experience at one crossing in Bangkok recently, Continuous Integration came to mind. Continuous Integration is a practice now widely adopted across the industry. Join a development team and they will probably be using tools such as Jenkins, Bamboo and Team City to monitor the build process. All these tools use indicators very similar to a Pedestrian Crossing.

Lets take Jenkins for example:

Blue Ball = Everything appears Good.

Red Ball = Something went wrong.

These coloured indicators look simple but in the same way as pedestrian crossings, they influence behaviour in different ways.

Lets take the following two teams:

Team A

The build fails and a Red light is shown on the Jenkins dashboard. The team stops, identifies the source of the failure, perhaps by nudging the last person who checked in. The source of the problem is identified, rectified and build is run returning to normal.

Team B

The build fails and a Red light is shown on the Jenkins dashboard. The team ignores the failure, continues checking-in and the builds continue to fail. Later that day, a developer in the team identifies a compile issue locally, checks-in a fix. The build returns to normal.

How do you cross the street?

What actions we take based upon the build indicator is influenced  by a number of factors. I’ve seen teams confidence of build indicators eroded by false positives/negatives leading to ignorance of builds. However, the biggest factor in my experience is team culture.

In the example of Team A, they are clearly influenced by their CI tool and a culture to investigate problems quickly and implement solutions. However in the example of Team B, their culture is to ignore the build failure potentially with the view that it will be resolved at a later date.

So what is your teams behaviour towards your Continuous Integration tool?

Are you like the Japanese? Do you stop when the build goes Red?

Or…..

Are you like the French who in most cases ignore the warning signs?

In a perfect world we’d all agree that if the pedestrian light says stop, we would all agree thats the best action to take. However, i’m sure we have all crossed the road, ignoring the sign.

Maybe it’s the same for build indicators, if the build is Red, maybe its OK to ignore……….sometimes?

Ignorance is bliss

Ignoring builds might be ok in some cases but the danger comes when we grow a team culture that blindly ignores the warning signs. The occasional ignored failed build can often develop into a culture where build failures are always ignored. This culture might yield some good results but it’s likely to result in some near misses, like this gentleman: