C#

Boa Constrictor Intro Video with Transcript

The Video

Boa Constrictor is the .NET Screenplay Pattern, and I’m its lead developer. Check out this intro video to learn why we need the Screenplay Pattern and how to use it with Boa Constrictor.

The Transcript

[Camera]

Hello, everyone! My name is Andrew Knight, or “Pandy” for short. I’m the Automation Panda – I build solutions to testing problems. Be sure to read my blog and follow me on Twitter at “AutomationPanda”.

Today, I’m going to introduce you to a new test automation library called Boa Constrictor, the .NET Screenplay Pattern. Boa Constrictor can help you make better interactions for better automation. Its primary use cases are Web UI and REST API interactions, but it can be extended to handle any type of interaction.

My team and I at PrecisionLender originally developed Boa Constrictor as the cornerstone of our .NET end-to-end test automation solution. We found the Screenplay Pattern to be a great way to scale our test development, avoid duplicate code, and stay focused on behaviors. In October 2020, together with help from our parent company Q2, we released Boa Constrictor as an open source project.

In this video, we will cover three things:

  1. First, problems with traditional ways of automating interactions.
  2. Second, why the Screenplay Pattern is a better way.
  3. Third, how to use the Screenplay Pattern with Boa Constrictor in C#.

Since Boa Constrictor is open source, you can check out its repository. I’ll paste the link below: https://github.com/q2ebanking/boa-constrictor. The repository also has a hands-on tutorial you can try. Make sure to have Visual Studio and some .NET skills because the code is written in C#.

My main goal with the Boa Constrictor project is to help improve test automation practices. For so long, our industry has relied on page objects, and I think it’s time we talk about a better way. Boa Constrictor strives to make that easy.

[Slide]

To start, let’s define that big “I” word I kept tossing around:

[Slide]

Interactions.

[Slide]

Simply put, interactions are how users operate software. For this video, I’ll focus on Web UI interactions, like clicking buttons and scraping text.

[Slide]

Interactions are indispensable to testing. The simplest way to define “testing” is interaction plus verification. That’s it! You do something, and you make sure it works.

Think about any functional test case that you have ever written or executed. The test case was a step-by-step procedure, in which each step had interactions and verifications.

[Slide]

Here’s an example of a simple DuckDuckGo search test. DuckDuckGo is a search engine like Google or Yahoo. The steps here are very straightforward.

[Slide]

Opening the search engine requires navigation.

[Slide]

Searching for a phrase requires entering keystrokes and clicking the search button.

[Slide]

Verifying results requires scraping the page title and result links from the new page. 

Interactions are everywhere!

[Slide]

Unfortunately, our industry struggles to handle automated Web UI interactions well. Even though most teams use Selenium WebDriver in their test automation code, every team seems to use it differently. There’s lots of duplicate code and flakiness, too. Let’s take a look at the way many teams evolve their WebDriver-based interactions. I will use C# for code examples, and I will continue to use DuckDuckGo for testing.

[Slide]

When teams first start writing test automation code using Selenium WebDriver, they frequently write raw calls. Anyone familiar with the WebDriver API should recognize these calls.

[Slide]

The WebDriver object is initialized using, say, ChromeDriver for the Chrome browser.

[Slide]

The first step to open the search engine calls “driver dot navigate dot go to URL” with the DuckDuckGo website address.

[Slide]

The second step performs the search by fetching Web elements using “driver dot find element” with locators and then calling methods like “send keys” and “click”.

[Slide]

The third step uses assertions to verify the contents of the page title and the existence of result links.

[Slide]

Finally, at the end of the test, the WebDriver quits the browser for cleanup.

Like I said, these are all common WebDriver calls. Unfortunately, there’s a big problem in this code.

[Slide]

Race conditions. There are three race conditions in this code in which the automation does NOT wait for the page to be ready before making interactions! WebDriver does not automatically wait for elements to load or titles to appear. Waiting is a huge challenge for Web UI automation, and it is one of the main reasons for “flaky” tests.

[Slide]

You could set an implicit wait that will make calls wait until target elements appear, but they don’t work for all cases, such as the title in race condition #2.

[Slide]

Explicit waits provide much more control over waiting timeout and conditions. They use a “WebDriverWait” object with a pre-set timeout value, and they must be placed explicitly throughout the code. Here, they are placed in the three spots where race conditions could happen. Each “wait dot until” call takes in a function that returns true when the condition is satisfied.

[Slide]

These waits are necessary, but they cause new problems. First, they cause duplicate code because Web element locators are used multiple times. Notice how “search form input homepage” is called twice.

[Slide]

Second, raw calls with explicit waits makes code less intuitive. If I remove the comments from each paragraph of code, what’s left is a wall of text. It is difficult to understand what this code does as a glance.

[Slide]

To remedy these problems, most teams use the Page Object Pattern. In the Page Object Pattern, each page is modeled as a class with locator variables and interaction methods. So, a “search page” class could look like this.

[Slide]

At the top, there could be a constant for the page URL and variables for the search input and search button locators. Notice how each has an intuitive name.

[Slide]

Next, there could be a variable to hold the WebDriver reference. This reference would come via dependency injection through the constructor.

[Slide]

The first method would be a “load” method that navigates the browser to the page’s URL.

[Slide]

And, the second method would be a “search” method that waits for the elements to appear, enters the phrase into the input field, and clicks the search button.

This page object class has a decent structure and a mild separation of concerns. Locators and interactions have meaningful names. Page objects require a few more lines of code that raw calls at first, but their parts can easily be reused.

[Slide]

The original test steps can be rewritten using this new SearchPage class. Notice how much cleaner this new code looks.

[Slide]

The other steps can be rewritten using page objects, too.

[Slide]

Unfortunately, page objects themselves suffer problems with duplication in their interaction methods.

[Slide]

Suppose a page object needs a method to click an element. We already know the logic: wait for the element to exist, and then click it.

But what about clicking another element? This method is essentially hard coded for one button.

[Slide]

A second “click” method is needed to click the other button.

[Slide]

Unfortunately, the code for both methods is the same. The code will be the same for any other click method, too. This is copy pasta, and it happens all the time in page objects. I’ve seen page objects grow to be thousands of lines long due to duplicative methods like this.

At this point, some teams will say, “Aha! More duplicate code? We can solve this problem with more Object-Oriented Programming!”

[Slide]

And they’ll create the infamous “base page”, a parent class for all other page object classes.

[Slide]

The base page will have variables for the WebDriver and the wait object.

[Slide]

It will also provide common interaction methods, such as this click method that can click on any element. Abstraction for the win!

[Slide]

Child pages will inherit everything from the base page. Child page interaction methods frequently just call base page methods.

I’ve seen many teams stop here and say, “This is good enough.” Unfortunately, this really isn’t very good at all!

[Slide]

The base page helps mitigate code duplication, but it doesn’t solve its root cause. Page objects inherently combine two separate concerns: page structure and interactions. Interactions are often generic enough to be used on any Web element. Coupling interaction code with specific locators or pages forces testers to add new page object methods for every type of interaction needed for an element. Every element could potentially need a click, a text, a “displayed”, or any other type of WebDriver interaction. That’s a lot of extra code that shouldn’t be necessary. The base page also becomes very top-heavy as testers add more and more code to share.

[Slide]

Most frustratingly, the page object code I showed here is merely one type of implementation. What do your page objects look like? I’d bet dollars to doughnuts that they look different than mine. Page objects are completely free form. Every team implements them differently. There’s no official version of the Page Object Pattern. There’s no conformity in its design. Even worse, within its design, there is almost no way for the pattern to enforce good practices. That’s why people argue whether page object locators should be public or private. Page objects would be better described as a “convention” than as a true design pattern.

[Slide]

There must be a better way to handle interactions. Thankfully, there is.

[Slide]

Let’s take a closer look at how interactions happen.

[Slide]

First, there is someone who initiates the interactions. Usually, this is a user. They are the ones making the clicks and taking the scrapes. Let’s call them the “Actor”.

[Slide]

Second, there is the thing under test. For our examples in this video, that’s a Web app. It has pages with elements. Web page structure is modeled using locators to access page elements from the DOM. Keep in mind, the thing under test could also be anything else, like a mobile app, a microservice, or even a command line.

[Slide]

Third, there are the interactions themselves. For Web apps, they could be simple clicks and keystrokes, or they could be more complex interactions like logging into the app or searching for a phrase. Each interaction will do the same type of operation on whatever target page or element it is given.

[Slide]

Finally, there are objects that enable Actors to perform certain types of Interactions. For example, browser interactions need a tool like Selenium WebDriver to make clicks and scrapes. Let’s call these things “Abilities”.

Actors, Abilities, and Interactions are each different types of concerns. We could summarize their relationship in one line.

[Slide]

Actors use Abilities to perform Interactions.

Actors use Abilities to perform Interactions.

[Slide]

This is the heart of the Screenplay Pattern. In the Page Object Convention, page objects become messy because concerns are all combined. The Screenplay Pattern separates concerns for maximal reusability and scalability.

[Slide]

So, let’s learn how to Screenplay, using Boa Constrictor.

[Slide]

“Boa Constrictor” is an open source C# implementation of the Screenplay Pattern my team and I developed at PrecisionLender. Like I said before, it is the cornerstone of PrecisionLender’s end-to-end test automation solution. It can be used with any .NET test framework, like SpecFlow or NUnit. The GitHub repository name is q2ebanking/boa-constrictor, and the NuGet package name is Boa.Constrictor.

[Slide]

Let’s rewrite that DuckDuckGo search test from before using Boa Constrictor. As you watch this video, I recommend just reading along with the code as it appears on screen to get the concepts. Trying to code along in real time might be challenging. After this video, you can take the official Boa Constrictor tutorial to get hands-on with the code.

[Slide]

To use Boa Constrictor, you will need to install the Boa Constrictor and Selenium WebDriver NuGet packages. My example code will also use Fluent Assertions and ChromeDriver.

[Slide]

The Actor is the entity that initiates Interactions. All Screenplay calls start with an Actor. Most test cases need only one Actor.

The Actor class optionally takes two arguments. The first argument is a name, which can help describe who the actor is. The name will appear in logged messages. The second argument is a logger, which will send log messages from Screenplay calls to a target destination. Loggers must implement Boa Constrictor’s ILogger interface. ConsoleLogger is a class that will log messages to the system console. You can define your own custom loggers by implementing ILogger.

[Slide]

Abilities enable Actors to initiate Interactions. For example, an Actor needs a Selenium WebDriver instance to click elements on a Web page.

Read this new line in plain English: “The actor can browse the Web with a new ChromeDriver.” Boa Constrictor’s fluent-like syntax makes its call chains very readable. “actor dot Can” adds an Ability to an Actor.

[Slide]

“BrowseTheWeb” is the Ability that enables Actors to perform Web UI Interactions. “BrowseTheWeb dot With” provides the WebDriver object that the Actor will use, which, in this case, is a new ChromeDriver object. Boa Constrictor supports all browser types.

All Abilities must implement the IAbility interface. Actors can be given any number of Abilities. “BrowseTheWeb” simply holds a reference to the WebDriver object. Web UI Interactions will retrieve this WebDriver object from the Actor.

[Slide]

Before the Actor can call any WebDriver-based Interactions, the Web pages under test need models. These models should be static classes that include locators for elements on the page and possibly page URLs. Page classes should only model structure – they should not include any interaction logic.

The Screenplay Pattern separates the concerns of page structure from interactions. That way, interactions can target any element, maximizing code reusability. Interactions like clicks and scrapes work the same regardless of the target elements.

The SearchPage class has two members. The first member is a URL string named Url. The second member is a locator for the search input element named SearchInput.

A locator has two parts. First, it has a plain-language Description that will be used for logging. Second, it has a Query that is used to find the element on the page. Boa Constrictor uses Selenium WebDriver’s By queries. For convenience, locators can be constructed using the statically imported L method.

[Slide]

The Screenplay Pattern has two types of Interactions. The first type of Interaction is called a Task. A Task performs actions without returning a value. Examples of Tasks include clicking an element, refreshing the browser, and loading a page. These interactions all “do” something rather than “get” something.

Boa Constrictor provides a Task named Navigate for loading a Web page using a target URL. Read this line in plain English: “The actor attempts to navigate to the URL for the search page.” Again, Boa Constrictor’s fluent-like syntax is very readable. Clearly, this line will load the DuckDuckGo search page. 

[Slide]

“Actor dot attempts to” calls a Task. All Tasks must implement the ITask interface. When the Actor calls “AttemptsTo” on a task, it calls the task’s “PerformAs” method.

[Slide]

“Navigate” is the name of the task, and “dot to URL” provides the target URL.

[Slide]

The Navigate Task’s “PerformAs” method fetches the WebDriver object from the Actor’s Ability and uses it to load the given URL.

[Slide]

“Search page dot URL” comes from the SearchPage class we previously wrote. Putting the URL in the page class makes it universally available.

[Slide]

The second type of Interaction is called a Question. A Question returns an answer after performing actions. Examples of Questions include getting an element’s text, location, and appearance. Each of these interactions return some sort of value. 

Boa Constrictor provides a Question named ValueAttribute that gets the “value” of the text currently inside an input field. Read this line in plain English: “The actor asking for the value attribute of the search page’s search input element should be empty.”

[Slide]

“Actor dot asking for” calls a Question. All Questions must implement the IQuestion interface. When the Actor calls “AskingFor” or the equivalent “AsksFor” method, it calls the question’s “RequestAs” method.

[Slide]

“ValueAttribute” is the name of the Question, and “dot Of” provides the target Web element’s locator. 

[Slide]

The ValueAttribute’s “RequestAs” method fetches the WebDriver object, waits for the target element to exist on the page, and scrapes and returns its value attribute.

[Slide]

“Search page dot search input” is the locator for the search input field. It comes from the SearchPage class.

[Slide]

Finally, once the value is obtained, the test must make an assertion on it. “Should be empty” is a Fluent Assertion that verifies that the search input field is empty when the page is first loaded.

[Slide]

The test case’s next step is to enter a search phrase. Doing this requires two interactions: typing the phrase into the search input and clicking the search button. However, since searching is such a common operation, we can create a custom interaction for search by composing the lower-level interactions together.

[Slide]

The “SearchDuckDuckGo” task takes in a search phrase.

[Slide]

In its “PerformAs” method, it calls two other interactions: “SendKeys” and “Click”.

[Slide]

Using one task to combine these lower-level interactions makes the test code more readable and understandable. It also improves automation reusability. Read this line in plain English now: “The actor attempts to search DuckDuckGo for ‘panda’.” That’s concise and intuitive!

[Slide]

The last test case step should verify that result links appear after entering a search phrase. Unfortunately, this step has a race condition: the result page takes a few seconds to display result links. Automation must wait for those links to appear. Checking too early will make the test case fail.

Boa Constrictor makes waiting easy. Read this line in plain English: “The actor attempts to wait until the appearance of result page result links is equal to true.” In simpler terms, “Wait until the result links appear.”

[Slide]

“Wait” is a special Task. It will repeatedly call a Question until the answer meets a given condition.

[Slide]

For this step, the Question is the appearance of result links on the result page. Before links are loaded, this Question will return “false”. Once links appear, it will return “true”.

[Slide]

The Condition for waiting is for the answer value to become “true”. Boa Constrictor provides several conditions out of the box, such as equality, mathematical comparisons, and string matching. You can also implement custom conditions by implementing the “ICondition” interface.

[Slide]

Waiting is smart – it will repeatedly ask the question until the answer is met, and then it will move on. This makes waiting much more efficient than hard sleeps. If the answer does not meet the condition within the timeout, then the wait will raise an exception. The timeout defaults to 30 seconds, but it can be overridden.

Many of Boa Constrictor’s WebDriver-based interactions already handle waiting. Anything that uses a target element, such as “Click”, “SendKeys”, or “Text” will wait for the element to exist before attempting the operation. We saw this in some of the previous example code. However, there are times where explicit waits are needed. Interactions that query appearance or existence do not automatically wait.

[Slide]

The final step is to quit the browser. Boa Constrictor’s “QuitWebDriver” task does this. If you don’t quit the browser, then it will remain open and turn into a zombie. Always quit the browser. Furthermore, in whatever test framework you use, put the step to quit the browser in a cleanup or teardown routine so that it is called even when the test fails.

[Slide]

And there we have our completed test using Boa Constrictor’s Screenplay Pattern. All the separated concerns come together beautifully to handle interactions in a much better way.

[Slide]

As we said before, the Screenplay Pattern can be summed up in one line:

[Slide]

Actors [Slide] use Abilities [Slide] to perform Interactions.

It’s that simple. Actors use Abilities to perform Interactions.

[Slide]

For those who like Object-Oriented Programming, the Screenplay Pattern is, in a sense, a SOLID refactoring of the Page Object Convention. SOLID refers to five design principles for maintainability and extensibility. I won’t go into detail about each principle here because the information is a bit dense, but if you’re interested, then pause the video, snap a quick screenshot, and check out each of these principles later. Wikipedia is a good source. You’ll find that the Screenplay Pattern follows each one nicely.

[Slide]

So, why should you use the Screenplay Pattern over Page Object Convention or raw WebDriver calls? There are a few key reasons.

[Slide]

First, the Screenplay Pattern, and specifically the Boa Constrictor project, provide rich, reusable, reliable interactions out of the box. Boa Constrictor already has Tasks and Questions for every type of WebDriver-based interaction. Each one is battle-hardened and safe.

[Slide]

Second, Screenplay interactions are composable. Like we saw with searching for a phrase, you can easily combine interactions. This makes code easier to use and reuse, and it avoids lots of duplication.

[Slide]

Third, the Screenplay Pattern makes waiting easy using existing questions and conditions. Waiting is one of the toughest parts of black box automation.

[Slide]

Fourth, Screenplay calls are readable and understandable. They use a fluent-like syntax that reads more like prose than code.

[Slide]

Finally, the Screenplay Pattern, at its core, is a design pattern for any type of interaction. In this video, I showed how to use it for Web UI interactions, but the Screenplay Pattern could also be used for mobile, REST API, and other platforms. You can make your own interactions, too!

[Slide]

Overall, the Screenplay Pattern [Slide] provides better interactions [Slide] for better automation.

That’s the point. It’s not just another Selenium WebDriver wrapper. It’s not just a new spin on page objects. Screenplay is a great way to exercise any feature behaviors under test.

And, as we saw before…

[Slide]

The Screenplay Pattern isn’t that complicated. Actors use Abilities to perform Interactions. That’s it. The programming behind it just has some nifty dependency injection.

[Slide]

If you’d like to start using the Screenplay Pattern for your test automation, there are a few ways to get started.

[Slide]

If you are programming in C#, you can use Boa Constrictor, the library I showed in the examples. You can download Boa Constrictor as a NuGet package. It works with any .NET test framework, like SpecFlow and NUnit. I recommend taking the hands-on tutorial so you can develop a test automation project yourself with Boa Constrictor. Also, since Boa Constrictor is an open source project, I’d love for you to contribute!

[Slide]

If you are programming in Java or JavaScript, you can use Serenity BDD – a mature, complete test automation framework that includes the Screenplay Pattern. Serenity BDD greatly influenced Boa Constrictor, but the two are entirely separate projects. Boa Constrictor is NOT Serenity BDD for .NET. Instead, Boa Constrictor aims to be a simpler, standalone implementation of the Screenplay Pattern.

[Slide]

If none of those options suit you, then you could create your own. The Screenplay Pattern does require a bit of boilerplate code, but it’s worthwhile in the end. You can always reference code from Boa Constrictor and Serenity BDD.

[Slide]

Thank you so much for taking the time to learn more about the Screenplay Pattern and Boa Constrictor. I’d like to give special thanks to everyone at PrecisionLender and Q2 who helped make Boa Constrictor’s open source release happen.

Again, my name is Andrew Knight. I’m the Automation Panda. Be sure to read my blog, follow me on Twitter, and reach out to me if you’d like to join the Boa Constrictor project! Thank you.

Introducing Boa Constrictor: The .NET Screenplay Pattern

Today, I’m excited to announce the release of a new open source project for test automation: Boa Constrictor, the .NET Screenplay Pattern!

The Screenplay Pattern helps you make better interactions for better automation. The pattern can be summarized in one line: Actors use Abilities to perform Interactions.

  • Actors initiate Interactions. Every test has an Actor.
  • Abilities enable Actors to perform Interactions. They hold objects that Interactions need, like WebDrivers or REST API clients.
  • Interactions exercise behaviors under test. They could be clicks, requests, commands, and anything else.

This separation of concerns makes Screenplay code very reusable and scalable, much more so than traditional page objects. Check it out, here’s a C# script to test a search engine:

// Create the Actor
IActor actor = new Actor(logger: new ConsoleLogger());

// Add an Ability to use a WebDriver
actor.Can(BrowseTheWeb.With(new ChromeDriver()));

// Load the search engine
actor.AttemptsTo(Navigate.ToUrl(SearchPage.Url));

// Get the page's title
string title = actor.AsksFor(Title.OfPage());

// Search for something
actor.AttemptsTo(Search.For("panda"));

// Wait for results
actor.AttemptsTo(Wait.Until(
    Appearance.Of(ResultPage.ResultLinks),
    IsEqualTo.True()));

Boa Constrictor provides many interactions for Selenium WebDriver and RestSharp out of the box, like Navigate, Title, and Appearance shown above. It also lets you compose interactions together, like how Search is a composition of typing and clicking.

Over the past two years, my team and I at PrecisionLender, a Q2 Company, developed Boa Constrictor internally as the cornerstone of Boa, our comprehensive end-to-end test automation solution. We were inspired by Serenity BDD‘s Screenplay implementation. After battle-hardening Boa Constrictor with thousands of automated tests, we are releasing it publicly as an open source project. Our goal is to help everyone make better interactions for better test automation.

If you’d like to give Boa Constrictor a try, then start with the tutorial. You’ll implement that search engine test from above in full. Then, once you’re ready to use it for some serious test automation, add the Boa.Constrictor NuGet package to your .NET project and go!

You can view the full source code on GitHub at q2ebanking/boa-constrictor. Check out the repository for full information. In the coming weeks, we’ll be developing more content and code. Since Boa Constrictor is open source, we’d love for you to contribute to the project, too!

Should We Rewrite Our Test Automation in Another Language?

A Twitter friend recently asked me the following question:

I work in a Microsoft shop. We have 40 developers who use .NET (C#). We also have several manual testers and 5 automation engineers who developed our test automation solution in Python. However, our leadership wants to move everything completely to C#.

Would it be better to (a) train 40 .NET developers in Python to use the existing test solution or (b) train the testers in .NET and port the tests to C#?

This is a very tough question. It’s not as simple as asking for the best test automation language because there are people, positions, and solutions already in place. Honestly, I can’t give a conclusive answer without more context, but I can offer five points of advice.

What is the state of the Python test solution?

How big and how bad is the existing Python test automation solution? Rewriting tests that already work fine has low return-on-investment. However, rewriting tests that have problems like flakiness or false positives might be worthwhile. More tests means more time, too. Please read my article, Our Test Automation Has Problems. Should We Start Over?, to learn what problems would warrant a rewrite.

Why not have two test solutions?

If the existing Python tests are fine, then rewriting them is a huge opportunity cost. Instead of rewriting existing tests, developers and testers could spend their time writing only the new tests in a new C# solution. The Python solution would be “legacy” and would not have any new tests added to it. Old tests would disappear with deprecated features, too. Eventually, the C# tests would take over. The main drawback for this possibility is the continued maintenance of a Python stack.

Do the manual testers have any programming experience?

Many manual testers do not have strong programming skills. Some may not have any programming skills at all! They will have a big learning curve when training to do test automation. Python would be a much easier language for them to learn than C# because it is concise, readable, and friendly for beginners. Conversely, Python would be fairly easy for C# developers to learn as they go.

What advantages will conformity bring?

Retraining workers and rewriting code is no small task. From a business perspective, they are investment costs. There must be significant returns that outweigh the cost of the transition. Make sure those returns are known and real.

Will developers also automate tests?

Many teams choose to write their test automation code in the same language as the product code so that developers can more easily automate tests. However, in my experience, developers typically don’t write many tests, especially when others on the team are dedicated testers. Test automation is difficult and has unique challenges. Some developers have bad attitudes about testing, too. Changing the language probably won’t change the deeper issues.

Final Thoughts

The decision to choose between C# and Python for test automation is very personal for me. I faced this choice directly when I started working at PrecisionLender. Even though I deeply love Python, we chose to use C#. It was the right choice: we were a Microsoft shop with no test solution (yet) and no Python stack in place. My team and I have no regrets.

There is nothing with test automation that either language can’t do. Both are solid choices. The best choice for a team depends more upon the team’s situation than differences between these languages.

NuGet Quick Reference

What is NuGet?

NuGet is a package manager for Microsoft .NET. It installs packages and manages dependencies for .NET projects. It is like Maven (Java) or pip (Python). The NuGet Gallery hosts thousands of popular packages like Json.NET, NUnit, and jQuery. If you develop .NET applications (like in C#), then you probably need to use NuGet.

Installing Packages

The easiest way to use NuGet is through Visual Studio, which includes NuGet features by default. Packages are managed per project. Right-click on a project in Solution Explorer and select “Manage NuGet Packages…” to open the project’s package manager page.

  • The Browse tab lets you search and install new packages.
  • The Installed tab shows which packages are installed and can uninstall them.
  • The Updates tab lets you update packages to their latest versions.

Nuget Package Manager Page

The NuGet Package Manager page for a project in Visual Studio

When packages are installed and updated, NuGet also pulls any dependencies they require. Visual Studio also creates a packages.config file for all dependencies. Then, just build and run!

<?xml version="1.0" encoding="utf-8"?>
<packages>
<package id="FluentAssertions" version="5.4.1" targetFramework="net461" />
<package id="Newtonsoft.Json" version="11.0.2" targetFramework="net461" />
<package id="SpecFlow" version="2.4.0" targetFramework="net461" />
<package id="SpecRun.Runner" version="1.8.0" targetFramework="net461" />
<package id="SpecRun.SpecFlow" version="1.8.0" targetFramework="net461" />
<package id="SpecRun.SpecFlow.2-4-0" version="1.8.0" targetFramework="net461" />
<package id="System.ValueTuple" version="4.5.0" targetFramework="net461" />
</packages>

NuGet Configuration

NuGet can be configured using a NuGet.Config file. This file can be placed under a project directory, a solution directory, or a system-wide location. One of the most common settings is the package sources: NuGet uses the public nuget.org repository by default, but others (like private company repos) can also be added. Check the nuget.config reference online for docs on all options. (Package sources can also be configured through Visual Studio under Tools > NuGet Package Manager > Package Manager Settings.)

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<packageSources>
<add key="nuget.org" value="https://www.nuget.org/api/v2/" />
<add key="my.company.com" value="https://my.company.com/httpAuth/app/nuget/v1/FeedService.svc/" />
</packageSources>
</configuration>

NuGet Package Manager Console

Sometimes, it’s helpful to control NuGet directly through the Package Manager Console. From the menu bar: Tools > NuGet Package Manager > Package Manager Console. For example, when packages get messed up, I’ll run “Update-Package -Reinstall” to reinstall everything. (Right-clicking the solution and selecting “Restore NuGet Packages” never seems to work for me.) Check the help command or the official guide for more info.

Nuget Package Manager Console

The NuGet Package Manager Console in Visual Studio

NuGet CLI

The NuGet CLI nuget.exe provides the full extent of NuGet features, including the ability to make packages. It is more powerful than the Package Manager Console. It must be installed independently – it does not come with Visual Studio. Check the NuGet CLI reference online for full details. The .NET Core CLI dotnet.exe can also be used for managing packages. See the feature comparison for the differences.

nuget CLI

The NuGet CLI

Creating a NuGet Package

A NuGet package is basically a ZIP file with a .nupkg extension. It typically contains an assembly DLL and maybe other related files. Creating a NuGet package is pretty easy:

  1. Install the NuGet CLI.
  2. Create a .nuspec file for the project.
  3. Add appropriate settings to the .nuspec file.
  4. Run the “nuget pack” command to create the .nupkg file.
  5. Publish the .nupkg file to the desired destination.

The .nuspec file can be created by running the “nuget spec” command in the project’s directory. The generated <project-name>.nuspec file will contain replacement tokens that will be substituted with values from the project’s AssemblyInfo when the package is built. Make sure to set AssemblyInfo values appropriately for the substitution. The version is especially important, and the automatic version format may be useful for guaranteeing uniqueness. Be sure to add any packages upon which the project depends as dependencies, too. (The .nuspec file can also be created manually.) Refer to the .nuspec reference for full details.

The standard package creation command is “nuget pack <project-name>.nuspec”. However, if the .nuspec file contains replacement tokens, then use “nuget pack <project-name>.csproj” instead. Once the package is created, it can be published publicly to nuget.org or to a private NuGet feed.

Below is an example .nuspec file with replacement tokens:

<?xml version="1.0"?>
<package >
<metadata>
<id>$id$</id>
<version>$version$</version>
<title>$title$</title>
<authors>$author$</authors>
<owners>$author$</owners>
<requireLicenseAcceptance>false</requireLicenseAcceptance>
<description>$description$</description>
<copyright>$copyright$</copyright>
<tags>tag1 tag2</tags>
<dependencies>
<dependency id="Newtonsoft.Json" version="11.0.2" />
<dependency id="RestSharp" version="106.3.1" />
<dependency id="Selenium.Support" version="3.14.0" />
<dependency id="Selenium.WebDriver" version="3.14.0" />
</dependencies>
</metadata>
</package>

Resources

 

Clicking Web Elements with Selenium WebDriver

Selenium WebDriver is the most popular open source package for Web UI test automation. It allows tests to interact directly with a web page in a live browser. However, using Selenium WebDriver can be very frustrating because basic interactions often lack robustness, causing intermittent errors for tests.

The Basics

One such vulnerable interaction is clicking elements on a page. Clicking is probably the most common interaction for tests. In C#, a basic click would look like this:

webDriver.FindElement(By.Id("my-id")).Click();

This is the easy and standard way to click elements using Selenium WebDriver. However, it will work only if the targeted element exists and is visible on the page. Otherwise, the WebDriver will throw exceptions. This is when programmers pull their hair out.

Waiting for Existence

To avoid race conditions, interactions should not happen until the target element exists on the page. Even split-second loading times can break automation. The best practice is to use explicit waits before interactions with a reasonable timeout value, like this:

const int timeoutSeconds = 15;
var ts = new TimeSpan(0, 0, timeoutSeconds);
var wait = new WebDriverWait(webDriver, ts);

wait.Until((driver) => driver.FindElements(By.Id("my-id")).Count > 0);
webDriver.FindElement(By.Id("my-id")).Click();

Other Preconditions

Sometimes, Web elements won’t appear without first triggering something else. Even if the element exists on the page, the WebDriver cannot click it until it is made visible. Always look for the proper way to make that element available for clicking. Click on any parent panels or expanders first. Scroll if necessary. Make sure the state of the system should permit the element to be clickable.

If the element is scrolled out of view, move to the element before clicking it:

new Actions(webDriver)
    .MoveToElement(webDriver.FindElement(By.Id("my-id")))
    .Click()
    .Perform();

Last Ditch Efforts

Nevertheless, there are times when clickable elements just don’t cooperate. They just can’t seem to be made visible. When all else fails, drop directly into JavaScript:

((IJavaScriptExecutor)webDriver).ExecuteScript(
    "arguments[0].click();",
    webDriver.FindElement(By.Id("my-id")));

Do this only when absolutely necessary. It is a best practice to use Selenium WebDriver methods because they make automated interaction behave more like a real user than raw JavaScript calls. Make sure to give good reasons in code comments whenever doing this, too.

Final Advice

This article was written specifically for clicks, but its advice can be applied to other sorts of interactions, too. Just be smart about waits and preconditions.

Note: Code examples on this page are written in C#, but calls are similar for other languages supported by Selenium WebDriver.

5 Things I Love About SpecFlow

SpecFlow, a.k.a. “Cucumber for .NET,” is a leading BDD test automation framework for .NET. Created by Gáspár Nagy and maintained as a free, open source project on GitHub by TechTalk, SpecFlow presently has almost 3 million total NuGet downloads. I’ve used it myself at a few companies, and, I must say as an automationeer, it’s awesome! SpecFlow shares a lot in common with other Cucumber frameworks like Cucumber-JVM, but it is not a knockoff – it excels in many ways. Below are five features I love about SpecFlow.

#1: Declarative Specification by Example

SpecFlow is a behavior-driven test framework. Test cases are written as Given-When-Then scenarios in Gherkin “.feature” files. For example, imagine testing a cucumber basket:

Feature: Cucumber Basket
  As a gardener,
  I want to carry many cucumbers in a basket,
  So that I don’t drop them all.
  
  @cucumber-basket
  Scenario: Fill an empty basket with cucumbers
    Given the basket is empty
    When "10" cucumbers are added to the basket
    Then the basket is full

Notice a few things:

  • It is declarative in that steps indicate what should be done at a high level.
  • It is concise in that a full test case is only a few lines long.
  • It is meaningful in that the coverage and purpose of the test are intuitively obvious.
  • It is focused in that the scenario covers only one main behavior.

Gherkin makes it easy to specify behaviors by example. That way, everybody can understand what is happening. C# code will implement each step in lower layers. Even if your team doesn’t do the full-blown BDD process, using a BDD framework like SpecFlow is still great for test automation. Test code naturally abstracts into separate layers, and steps are reusable, too!

#2: Context is King

Safely sharing data (e.g., “context”) between steps is a big challenge in BDD test frameworks. Using static variables is a simple yet terrible solution – any class can access them, but they create collisions for parallel test runs. SpecFlow provides much better patterns for sharing context.

Context injection is SpecFlow’s simple yet powerful mechanism for inversion of control (using BoDi). Any POCOs can be injected into any step definition class, either using default values or using a specific initialization, by declaring the POCO as a step def constructor argument. Those instances will also be shared instances, meaning steps across different classes can share the same objects! For example, steps for Web tests will all need a reference to the scenario’s one WebDriver instance. The context-injected objects are also created fresh for each scenario to protect test case independence.

Another powerful context mechanism is ScenarioContext. Every scenario has a unique context: title, tags, feature, and errors. Arbitrary objects can also be stored in the context object like a Dictionary, which is a simple way to pass data between steps without constructor-level context injection. Step definition classes can access the current scenario context using the static ScenarioContext.Current variable, but a better, thread-safe pattern is to make all step def classes extend the Steps class and simply reference the ScenarioContext instance variable.

#3: Hooks for Any Occasion

Hooks are special methods that insert extra logic at critical points of execution. For example, WebDriver cleanup should happen after a Web test scenario completes, no matter the result. If the cleanup routine were put into a Then step, then it would not be executed if the scenario had a failure in a When step. Hooks are reminiscent of Aspect-Oriented Programming.

Most BDD frameworks have some sort of hooks, but SpecFlow stands out for its hook richness. Hooks can be applied before and after steps, scenario blocks, scenarios, features, and even around the whole test run. (Cucumber-JVM, by contrast, does not support global hooks.) Hooks can be selectively applied using tags, and they can be assigned an order if a project has multiple hooks of the same type. Hook methods will also be picked up from any step definition class. SpecFlow hooks are just awesome!

#4: Thorough Outline Templating

Scenario Outlines are a standard part of Gherkin syntax. They’re very useful for templating scenarios with multiple input combinations. Consider the cucumber basket again:

Feature: Cucumber Basket
  
  Scenario Outline: Add cucumbers to the basket
    Given the basket has "<initial>" cucumbers
    When "<some>" cucumbers are added to the basket
    Then the basket has "<total>" cucumbers

    Examples: Counts
      | initial | some | total |
      | 1       | 2    | 3     |
      | 5       | 3    | 8     |

All BDD frameworks can parametrize step inputs (shown in double quotes). However, SpecFlow can also parametrize the non-input parts of a step!

Feature: Cucumber Basket
  
  Scenario Outline: Use the cucumber basket
    Given the basket has "<initial>" cucumbers
    When "<some>" cucumbers are <handled-with> the basket
    Then the basket has "<total>" cucumbers

    Examples: Counts
      | initial | some | handled-with | total |
      | 1       | 2    | added to     | 3     |
      | 5       | 3    | removed from | 2     |

The step definitions for the add and remove steps are separate. The step text for the action is parametrized, even though it is not a step input:

[When(@"""(\d+)"" cucumbers are added to the basket")]
public void WhenCucumbersAreAddedToTheBasket(int count) { /* */ }

[When(@"""(\d+)"" cucumbers are removed from the basket")]
public void WhenCucumbersAreRemovedFromTheBasket(int count) { /* */ }

That’s cool!

#5: Test Thread Affinity

SpecFlow can use any unit test runner (like MsTest, NUnit, and xUnit.net), but TechTalk provides the official SpecFlow+ Runner for a licensed fee. I’m not associated with TechTalk in any way, but the SpecFlow+ Runner is worth the cost for enterprise-level projects. It has a friendly command line, a profile file to customize execution, parallel execution, and nice integrations.

The major differentiator, in my opinion, is its test thread affinity feature. When running tests in parallel, the major challenge is avoiding collisions. Test thread affinity is a simple yet powerful way to control which tests run on which threads. For example, consider testing a website with user accounts. No two tests should use the same user at the same time, for fear of collision. Scenarios can be tagged for different users, and each thread can have the affinity to run scenarios for a unique user. Some sort of parallel isolation management like test thread affinity is absolutely necessary for test automation at scale. Given that the SpecFlow+ Runner can handle up to 64 threads (according to TechTalk), massive scale-up is possible.

But Wait, There’s More!

SpecFlow is an all-around great test automation framework, whether or not your team is doing full BDD. Feel free to add comments below about other features you love (or *gasp* hate) about SpecFlow!

 

BDD 101: Frameworks

Every major programming language has a BDD automation framework. Some even have multiple choices. Building upon the structural basics from the previous post, this post provides a survey of the major frameworks available today. Since I cannot possibly cover every BDD framework in depth in this 101 series, my goal is to empower you, the reader, to pick the best framework for your needs. Each framework has support documentation online justifying its unique goodness and detailing how to use it, and I would prefer not to duplicate documentation. Use this post primarily as a reference. (Check the Automation Panda BDD page for the full table of contents.)

Major Frameworks

Most BDD frameworks are Cucumber versions, JBehave derivatives inspired by Dan North, or non-Gherkin spec runners. Some put behavior scenarios into separate files, while others put them directly into the source code.

C# and Microsoft .NET

SpecFlow, created by Gáspár Nagy, is arguably the most popular BDD framework for Microsoft .NET languages. Its tagline is “Cucumber for .NET” – thus fully compliant with Gherkin. SpecFlow also has polished, well-designed hookscontext injection, and parallel execution (especially with test thread affinity). The basic package is free and open source, but SpecFlow also sells licenses for SpecFlow+ extensions. The free version requires a unit test runner like MsTest, NUnit, or xUnit.net in order to run scenarios. This makes SpecFlow flexible but also feels jury-rigged and inelegant. The licensed version provides a slick runner named SpecFlow+ Runner (which is BDD-friendly) and a Microsoft Excel integration tool named SpecFlow+ Excel. Microsoft Visual Studio has extensions for SpecFlow to make development easier.

There are plenty of other BDD frameworks for C# and .NET, too. xBehave.net is an alternative that pairs nicely with xUnit.net. A major difference of xBehave.net is that scenario steps are written directly in the code, instead of in separate text (feature) files. LightBDD bills itself as being more lightweight than other frameworks and basically does some tricks with partial classes to make the code more readable. NSpec is similar to RSpec and Mocha and uses lambda expressions heavily. Concordion offers some interesting ways to write specs, too. NBehave is a JBehave descendant, but the project appears to be dead without any updates since 2014.

Java and JVM Languages

The main Java rivalry is between Cucumber-JVM and JBehave. Cucumber-JVM is the official Cucumber version for Java and other JVM languages (Groovy, Scala, Clojure, etc.). It is fully compliant with Gherkin and generates beautiful reports. The Cucumber-JVM driver can be customized, as well. JBehave is one of the first and foremost BDD frameworks available. It was originally developed by Dan North, the “father of BDD.” However, JBehave is missing key Gherkin features like backgrounds, doc strings, and tags. It was also a pure-Java implementation before Cucumber-JVM existed. Both frameworks are widely used, have plugins for major IDEs, and distribute Maven packages. This popular but older article compares the two in slight favor of JBehave, but I think Cucumber-JVM is better, given its features and support.

The Automation panda article Cucumber-JVM for Java is a thorough guide for the Cucumber-JVM framework.

Java also has a number of other BDD frameworks. JGiven uses a fluent API to spell out scenarios, and pretty HTML reports print the scenarios with the results. It is fairly clean and concise. Spock and JDave are spec frameworks, but JDave has been inactive for years. Scalatest for Scala also has spec-oriented features. Concordion also provides a Java implementation.

JavaScript

Almost all JavaScript BDD frameworks run on Node.js. Jasmine and Mocha are two of the most popular general-purpose JS test frameworks. They differ in that Jasmine has many features included (like assertions and spies) that Mocha does not. This makes Jasmine easier to get started (good for beginners) but makes Mocha more customizable (good for power users). Both claim to be behavior-driven because they structure tests using “describe” and “it-should” phrases in the code, but they do not have the advantage of separate, reusable steps like Gherkin. Personally, I consider Jasmine and Mocha to be behavior-inspired but not fully behavior-driven.

Other BDD frameworks are more true to form. Cucumber provides Cucumber.js for Gherkin-compliant happiness. Yadda is Gherkin-like but with a more flexible syntax. Vows provides a different way to approach behavior using more formalized phrase partitions for a unique form of reusability. The Cucumber blog argues that Cucumber.js is best due to its focus on good communication through plain language steps, whereas other JavaScript BDD frameworks are more code-y. (Keep in mind, though, that Cucumber would naturally boast of its own framework.) Other comparisons are posted here, here, here, and here.

PHP

The two major BDD frameworks for PHP are Behat and Codeception. Behat is the official Cucumber version for PHP, and as such is seen as the more “pure” BDD framework. Codeception is more programmer-focused and can handle other styles of testing. There are plenty of articles comparing the two – here, here, and here (although the last one seems out of date). Both seem like good choices, but Codeception seems more flexible.

Python

Python has a plethora of test frameworks, and many are BDD. behave and lettuce are probably the two most popular players. Feature comparison is analogous to Cucumber-JVM versus JBehave, respectively: behave is practically Gherkin compliant, while lettuce lacks a few language elements. Both have plugins for major IDEs. pytest-bdd is on the rise because it integrates with all the wonderful features of pytestradish is another framework that extends the Gherkin language to include scenario loops, scenario preconditions, and variables. All these frameworks put scenarios into separate feature files. They all also implement step definitions as functions instead of classes, which not only makes steps feel simpler and more independent, but also avoids unnecessary object construction.

Other Python frameworks exist as well. pyspecs is a spec-oriented framework. Freshen was a BDD plugin for Nose, but both Freshen and Nose are discontinued projects.

Ruby

Cucumber, the gold standard for BDD frameworks, was first implemented in Ruby. Cucumber maintains the official Gherkin language standard, and all Cucumber versions are inspired by the original Ruby version. Spinach bills itself as an enhancement to Cucumber by encapsulating steps better. RSpec is a spec-oriented framework that does not use Gherkin.

Which One is Best?

There is no right answer – the best BDD framework is the one that best fits your needs. However, there are a few points to consider when weighing your options:

  • What programming language should I use for test automation?
  • Is it a popular framework that many others use?
  • Is the framework actively supported?
  • Is the spec language compliant with Gherkin?
  • What type of testing will you do with the framework?
  • What are the limitations as compared to other frameworks?

Frameworks that separate scenario text from implementation code are best for shift-left testing. Frameworks that put scenario text directly into the source code are better for white box testing, but they may look confusing to less experienced programmers.

Personally, my favorites are SpecFlow and pytest-bdd. At LexisNexis, I used SpecFlow and Cucumber-JVM. For Python, I used behave at MaxPoint, but I have since fallen in love with pytest-bdd since it piggybacks on the wonderfulness of pytest. (I can’t wait for this open ticket to add pytest-bdd support in PyCharm.) For skill transferability, I recommend Gherkin compliance, as well.

Reference Table

The table below categorizes BDD frameworks by language and type for quick reference. It also includes frameworks in languages not described above. Recommended frameworks are denoted with an asterisk (*). Inactive projects are denoted with an X (x).

Language Framework Type
C Catch In-line Spec
C++ Igloo In-line Spec
C# and .NET Concordion
LightBDD
NBehave x
NSpec
SpecFlow *
xBehave.net
In-line Spec
In-line Gherkin
Separated semi-Gherkin
In-line Spec
Separated Gherkin
In-line Gherkin
Golang Ginkgo In-line Spec
Java and JVM Cucumber-JVM *
JBehave
JDave x
JGiven *
Scalatest
Spock
Separated Gherkin
Separated semi-Gherkin
In-line Spec
In-line Gherkin
In-line Spec
In-line Spec
JavaScript Cucumber.js *
Yadda
Jasmine
Mocha
Vows
Separated Gherkin
Separated semi-Gherkin
In-line Spec
In-line Spec
In-line Spec
Perl Test::BDD::Cucumber Separated Gherkin
PHP Behat
Codeception *
Separated Gherkin
Separated or In-line
Python behave *
freshen x
lettuce
pyspecs
pytest-bdd *
radish
Separated Gherkin
Separated Gherkin
Separated semi-Gherkin
In-line Spec
Separated semi-Gherkin
Separated Gherkin-plus
Ruby Cucumber *
RSpec
Spinach
Separated Gherkin
In-line Spec
Separated Gherkin
Swift / Objective C Quick In-line Spec

 

[4/22/2018] Update: I updated info for C# and Python frameworks.

The Best Programming Language for Test Automation

Which programming languages are best for writing test automation? There are several choices – just look at this list on Wikipedia and this cool decision graphs for choosing languages. While this topic can quickly devolve into a spat over personal tastes, I do believe there are objective reasons for why some languages are better for automating test cases than others.

Dividing Test Layers

First of all, unit tests should always be written in the same language as the product under test. Otherwise, they would definitionally no longer be unit tests! Unit tests are white box and need direct access to the product source code. This allows them to cover functions, methods, and classes.

The question at hand pertains more to higher-layer functional tests. These tests fall into many (potentially overlapping) categories: integration, end-to-end, system, acceptance, regression, and even performance. Since they are all typically black box, higher-layer tests do not necessarily need to be written in the same language as the product under test.

My Opinionated Choices

Personally, I think Python is today’s best all-around language for test automation. Python is wonderful because its conciseness lets the programmer expressively capture the essence of the test case. It also has very rich test support packages. Check out this article: Why Python is Great for Test AutomationJava is a good choice as well – it has a rich platform of tools and packages, and continuous integration with Java is easy with Maven/Gradle/ANT and Jenkins. I’ve heard that Ruby is another good choice for reasons similar to Python, but I have not used it myself.

Some languages are good in specific domains. For example, JavaScript is great for pure web app testing (à la Jasmine, Karma, and Protractor) but not so good for general purposes (despite Node.js running anywhere). A good reason to use JavaScript for testing would be MEAN stack development. TypeScript would be even better because it is safer and scales better. C# is great for Microsoft shops and has great test support, but it lives in the Microsoft bubble. .NET development tools are not always free, and command line operations can be painful.

Other languages are poor choices for test automation. While they could be used for automation, they likely should not be used. C and C++ are inconvenient because they are very low-level and lack robust frameworks. Perl is dangerous because it simply does not provide the consistency and structure for scalable, self-documenting code. Functional languages like LISP and Haskell are difficult because they do not translate well from test case procedures. They may be useful, however, for some lower-level data testing.

8 Criteria for Evaluation

There are eight major points to consider when evaluating any language for automation. These criteria specifically assess the language from a perspective of purity and usability, not necessarily from a perspective of immediate project needs.

  1. Usability.  A good automation language is fairly high-level and should handle rote tasks like memory management. Lower learning curves are preferable. Development speed is also important for deadlines.
  2. Elegance. The process of translating test case procedures into code must be easy and clear. Test code should also be concise and self-documenting for maintainability.
  3. Available Test Frameworks. Frameworks provide basic needs such as fixtures, setup/cleanup, logging, and reporting. Examples include Cucumber and xUnit.
  4. Available Packages. It is better to use off-the-shelf packages for common operations, such as web drivers (Selenium), HTTP requests, and SSH.
  5. Powerful Command Line. A good CLI makes launching tests easy. This is critical for continuous integration, where tests cannot be launched manually.
  6. Easy Build Integration. Build automation should launch tests and report results. Difficult integration is a DevOps nightmare.
  7. IDE Support. Because Notepad and vim just don’t cut it for big projects.
  8. Industry Adoption. Support is good. If the language remains popular, then frameworks and packages will be maintained well.

Below, I rated each point for a few popular languages:

Python Java JavaScript C# C/C++ Perl
Usability  awesome  good  good  good  terrible  poor
Elegance  awesome  good  okay  good  poor  poor
Available Test Frameworks  awesome  awesome  awesome  good  okay  poor
Available Packages  awesome  awesome  okay  good  good  good
Powerful Command Line  awesome  good  good  okay  poor  okay
Easy Build Integration  good  good  good  good  poor  poor
IDE Support  good  awesome  good  good  okay  terrible
Industry Adoption  awesome  awesome  awesome  good  terrible  terrible

Conclusion

I won’t shy away from my preference for Python, but I recognize that they may not be the right choice for all situations. For example, when I worked at LexisNexis, we used C# because management wanted developers, who wrote the app in C#, to contribute to test automation.

Now, a truly nifty idea would be to create a domain-specific language for test automation, but that must be a topic for another post.

UPDATE: I changed some recommendations on 4/18/2018.