SpecFlow legacy support and migration to Reqnroll

Deep reference for reqnroll-testing. Consult when maintaining an existing SpecFlow project that has not migrated yet, or when executing the migration.

SpecFlow is end-of-life

SpecFlow was the standard .NET BDD runner for a decade. It is dead: Tricentis, which owned it, states "SpecFlow has been retired" (shiftsync.tricentis.com), specflow.org redirects there, and it "reached its end-of-life on December 31, 2024" with the GitHub projects deleted as of 1 January (reqnroll.net). The packages still install only because nuget.org will not delete existing ones - exactly how newcomers land on an unsupported dependency. New .NET BDD work targets Reqnroll; use this page only for existing SpecFlow projects, especially mid-migration.

Maintaining an existing SpecFlow project (legacy)

Package references (legacy):

<PackageReference Include="SpecFlow" Version="3.9.74" />
<PackageReference Include="SpecFlow.xUnit" Version="3.9.74" />
<PackageReference Include="SpecFlow.Tools.MsBuild.Generation" Version="3.9.74" />

Features are the same Gherkin as Reqnroll / Cucumber. Step bindings:

using TechTalk.SpecFlow;
using Xunit;

[Binding]
public class CartSteps
{
    [Given("a logged-in user")]
    public void GivenLoggedInUser() { /* ... */ }

    [When(@"I enter ""([^""]*)"" in the promo input")]
    public void WhenIEnter(string code) { /* ... */ }

    [Then(@"the subtotal updates to \$(\d+\.\d+)")]
    public void ThenSubtotalUpdates(decimal expected) { /* ... */ }
}

Compare to Reqnroll: using TechTalk.SpecFlow → using Reqnroll; decorators identical. Running is the same dotnet test (the runner is the .NET test framework - xUnit / NUnit / MsTest).

Migration path

Per reqnroll.net: "Compatible with SpecFlow, allowing quick migration of existing projects."

# 1. Remove SpecFlow packages
dotnet remove package SpecFlow
dotnet remove package SpecFlow.xUnit
dotnet remove package SpecFlow.Tools.MsBuild.Generation

# 2. Add Reqnroll equivalents
dotnet add package Reqnroll.xUnit
dotnet add package Reqnroll.Tools.MsBuild.Generation

// 3. Find/replace in code:
//   using TechTalk.SpecFlow → using Reqnroll
//   TechTalk.SpecFlow → Reqnroll

# 4. Run tests; fix any breakages
dotnet test

Most projects migrate in under a day; the migration is mostly mechanical.

Anti-patterns

Limitations of staying on SpecFlow

• Maintenance status. EOL - no bug fixes, no new features.
• .NET version compatibility. Newer .NET versions land on Reqnroll only.
• IDE plugin updates. SpecFlow plugins for VS / Rider are frozen; Reqnroll's are maintained.