Cucumber expressions support for SpecFlow v3.1 (SpecFlow plugin).

Note: Cucumber expression support will be hopefully added to the core SpecFlow package in a future version. But for the current SpecFlow versions, it can be already used using this plugin.

With Cucumber expressions you can specify your step definitions in a simpler way.

Instead of using regular expressions:

[When(@"I add (\d+) copies of the book ""([^""])"" into my basket")]

Use Cucumber expressions:

[When("I add {int} copies of the book {string} into my basket")]

Just simply add the CucumberExpressions.SpecFlow.3-1 NuGet package to your SpecFlow v3.1 project!

PM> Install-Package CucumberExpressions.SpecFlow.3-1

The plugin supports most of the features described in the Cucumber expressions documentation. You can use {int}, {float}, {word}, {string} and also the generic {} anonymous matching pattern. SpecFlow detects the parameter type of your method and performs the necessary conversation anyway.

You can also use the most common built-in types by (case sensitive) type name (without namespace): {Boolean}, {Byte}, {Int32}, {Decimal}, {Guid}, {DateTime}, etc.

The custom conversions can be used either with the anonymous parameter {} or with the target type name, like {Person}. To specify the conversion, you need to use the usual [StepArgumentTransformation] attribute:

[StepArgumentTransformation]
public Person ConvertPerson(string name)
{
  //...
}

It is mostly backwards compatible as it recognizes common regex patterns and uses regex mathching for them. If necessary you can force using the regex matcher by wrapping your pattern with ^ and $.

[When(@"^forced regex$")]

To be able to recognize Cucumber expression in your Visual Studio, the Visual Studio integration also has to be updated. Currently the Devreoom for SpecFlow (free, open-source) Visual Studio extension supports this new patterns.