Setting Up Verify for Approval Testing in C#: A Step-by-Step Guide
Welcome back to our journey through the landscapes of code with Verify as our guide. In our last post, "Mastering Approval Testing in C# with Verify: A Beginner's Guide", we introduced the concept of approval testing and why Verify stands out as a beacon for developers navigating the C# ecosystem. Today, we’re diving more deeply, exploring how to set up Verify in your C# projects and craft your first approval tests. Let’s demystify the process and show how seamlessly Verify integrates into your workflow, making your transition to approval testing smooth and downright enjoyable.
Setting Sail: Installing Verify
First, to embark on this adventure, you must bring Verify aboard your project. Fear not, for this is no Herculean task. You're already halfway there if you’re familiar with NuGet Package Manager. Open your project in Visual Studio, head to the NuGet Package Manager (either through the console or the GUI), and run the following command:
Install-Package Verify.Xunit
Note: We’re using Verify.Xunit in this example because we’re fans of xUnit, but if you’re more inclined towards NUnit or MSTest, Verify has covered you with dedicated packages for those frameworks.
The First Encounter: Crafting Your First Test
With Verify installed, it’s time to craft your first approval test. The beauty of Verify lies in its simplicity. Let’s say we have a function that generates a report as a string. We aim to ensure this report is generated correctly and captures all the intended details.
Here’s a simple example to get us started:
[Fact]
public async Task ReportGenerationTest()
{
var reportGenerator = new ReportGenerator();
var report = reportGenerator.GenerateReport();
await Verify(report);
}
In this snippet, ReportGenerator is our hypothetical class with a GenerateReport method that returns the report as a string. The magic happens with await Verify(report); – this line instructs Verify to capture the output of our report.
Under the Hood: What Happens Next?
When you run this test for the first time, Verify does something quite clever. Since there’s no approved output to compare against, it generates a .received. file containing the method's outputGenerateReport. Verify, then await your approval to make this the golden standard. You approve the output by simply renaming the .received. file to an .approved. file, either manually or using tools Verify integrates with, such as Diff tool integrations.
From this point forward, every time you run the test, Verify compares the newly generated report against the approved version. If there is any discrepancy, the test will fail, highlighting precisely what changed. This catches unintended changes and provides a clear, contextual insight into how and what has evolved in your output.
Sailing Further: Beyond Simple Strings
While we started with a simple string example, Verify’s prowess extends far beyond. With its capability to handle complex objects, files, and images, your testing horizon is as broad as the sea. Whether you’re testing API responses, database states, or UI snapshots, Verify can handle it all, turning the arduous task of writing and maintaining a plethora of assertions into a streamlined, efficient process.
Charting Your Course
As you incorporate Verify into your projects, you’ll find your tests becoming more concise and significantly more powerful. By focusing on the output’s entirety, you ensure that your tests genuinely reflect real-world use cases, making them more relevant and, ultimately, more valuable.
In our next posts, we’ll explore advanced features and best practices for approval testing with Verify, ensuring you’re well-equipped to tackle even the most daunting testing challenges. So, keep your compass handy, and let’s continue to navigate the uncharted waters of code quality together, with Verify as our steadfast ally.
Alexandre Cuva
