How-to: End to End Automated Testing with Specflow

End-to-End testing is about testing a full “slice” of an IS, from user input to tiers (DB, service provider) and back to the system output.

For this concern, at Betclic, we use 2 tools:

• Specflow: It’s a Behavior Driven Design framework, relying on the Business Readable DSL Gherkin, and integrated in Visual Studio.
• WebDriver (a.k.a. Selenium): A browser automation tool

Quick Behavior Driven Design Glossary

Spec (specification)

Description of how an information system should behave

Feature

Part of an Information System, that has its own behavior

Scenario

Part of a feature

Step

Atomic operation of a scenario

Setup

Visual Studio Extensions

Fisrt of all, install the Specflow VS extension.

Specflow extension for VS 2013

Nuget Packages

In your target test project, add the following packages:

• PM> Install-Package SpecFlow
• PM> Install-Package Selenium.WebDriver
• PM> Install-Package NFluent

App.config

By default, Specflow uses NUnit. As the recommended test framework is MSTest, you have to tune the concerned config section.

XML

<specFlow>
    <!-- For additional details on SpecFlow configuration
         options see http://go.specflow.org/docun-config -->
    <unitTestProvider name="MsTest" />
</specFlow>

Files Organisation

At the of the Test project, add a “Specs” and a “Steps” folders.The first one will hold the Gherkin files, the second one will contain the associated transcription of spec into C#.

First test

Description

Let us say we want to test the navigation of our menu bar.
In a default MVC Website, I added a new “StaticContent” controller, and added a link to it in the layout’s menu.
We want to check if a click on this link browses to the target page.

Gherkin

First, we create a “specification” in Gherkin langage.

Right-click on the Specs folder and add a new SpecFlow Feature file:

And name it “Navigation”. This file will specify all the business navigation rules over your website.
Add the following content:

Pretty self-describing, isn’t it? The main advantage of the Gherkin language is that everybody, from Business to QA people have the same understanding of it.
By sharing a common language, we are able to efficiently communicate, and build a system that purely reflects the business needs. Even better, you can build those specifications with the business and QA.

Translate to Steps

By right-clicking in the feature file and selecting “Generate Step definition”, you will launch a wizard tool that will create the step file skeleton.

Target the “Steps” folder before generating the steps.

You should have a new test file with 3 blocks:

Our scenario implies the use of a browser. Here comes WebDriver, that allows us to abstract the communication with the browser.

For this, we start by sharing the same instance of browser execution between the different steps of our secnario:

Now we are able to “web-drive” our browser with an easy API:

It’s a simple transcription of the scenario:

Given: Initial state, load the default page of the website

When: Description of an action, here, the click on the StaticContent page’s link

Then: the expected state: i.e., do we have browse to the StaticContent page ?

Run the test: a “web-driven” Firefox window will be launched by WebDriver/Selenium, and perform few actions.

Conclusion

In this article, we saw how to setup a functional environment for starting Behavior Driven Design on web application.

To achieve this, we rely on the pair Specflow / WebDriver.

More to come about WebDriver API, stay tuned!