SpecFlow with .NET Core

This is a solution for anybody trying to use SpecFlow with .NET Core 2.0, inspired by the work of SpecFlow.DotNet and SpecFlow.xUnitAdapter.

Currently, SpecFlow doesn't officially support .NET Core, despite ongoing work in that area. Until that offical support arrives, this package allows you to generate SpecFlow tests as part of a .NET Core test suite.

Installation

Assuming you are using Visual Studio, start by disabling the non-functioning code-behind generation provided by the SpecFlow tooling by removing the generator properties from the .feature files. For every feature file in your test project, you should remove these lines:

<ItemGroup>
	<Compile Update="MyFeature.feature.cs">
		<DesignTime>True</DesignTime>
		<AutoGen>True</AutoGen>
		<DependentUpon>MyFeature.feature</DependentUpon>
	</Compile>
</ItemGroup>

<ItemGroup>
	<None Update="MyFeature.feature">
		<Generator>SpecFlowSingleFileGenerator</Generator>
		<LastGenOutput>MyFeature.feature.cs</LastGenOutput>
	</None>
</ItemGroup>

You should then remove any *.feature.cs files left in your project.

Install and configure the package:

Install-Package Rhubarb.SpecFlow.NetCore

If you're running SpecFlow on anything other than NUnit, you need to have a specflow.json file in your test project. This file must be set to be copied to your output folder on every build and is used to configure your test runner (e.g. xunit):

{
    "specflow": {
        "unitTestProvider": {
            "name": "xunit"
        }
    }
}

You must also add this property your test project to make sure your copy of the SpecFlow assembly sits in your output folder alongside the specflow.json file.

<PropertyGroup>
    <!-- ... -->
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
    <!-- ... -->
</PropertyGroup>

How it works

This project is an extension to MSBuild which invokes the specflow.exe tool during the build process. The tool generates the *.feature.cs files normally produced by the SpecFlow extension to Visual Studio.

The specflow.exe tool runs using the .NET Framework and only works on .NET Framework projects. The MSBuild tasks generate a "shadow" project using the classic project structure, including an app.config file configured to the test framework you're using, and copies in all the *.feature files from your project. The *.feature.cs files create by the tool are then are added to the build so the unit tests appear in the compiled assembly.