Migrating from SpecFlow#

Reqnroll has been created based on the open-source codebase of SpecFlow, therefore it provides a high level of compatibility with SpecFlow. We can generally say that everything that has worked with SpecFlow also works with Reqnroll, but some names and the namespaces have been modified.

The key differences between SpecFlow and Reqnroll are the following:

  • All packages have been renamed from SpecFlow.* to Reqnroll.*. E.g. Reqnroll.MsTest.

  • The namespace of the classes has been changed from TechTalk.SpecFlow to Reqnroll and some classes that had SpecFlow in their name (e.g. ISpecFlowOutputHelper) have been renamed accordingly. An optional SpecFlow Compatibility Package has been created to migrate without changing all namespaces, see below.

  • There is a new DataTable alias for the Table class to better match Gherkin terminology. The Table class can still be used.

  • The main extension methods of the Assist helpers have been moved to the Reqnroll namespace, so that they can be used without an additional namespace using statement. The helpers are now referred to as DataTable Helpers.

  • The Reqnroll Visual Studio extension has been reworked in a way that it can handle both SpecFlow and Reqnroll projects (also for .NET 8.0).

  • The integration plugins that have been managed by SpecFlow have been also ported to work with Reqnroll (e.g. Reqnroll.Autofac). See Available Plugins.

  • The “SpecFlow.Actions” plugins that provide a ready-to-use support for different automation technologies (e.g. Selenium) are ported as Reqnroll.SpecFlowCompatibility.Actions.* packages (e.g. Reqnroll.SpecFlowCompatibility.Actions.Selenium).

This article provides you a step-by-step guidance to migrate SpecFlow projects to Reqnroll. There are two migration paths you can choose from:

  1. Migrate with the Reqnroll SpecFlow Compatibility Package: requires minimal change in the codebase.

  2. Migrate with namespace changes: requires simple changes, mostly doable with search-and-replace.

It is also worth mentioning that Reqnroll is based on the SpecFlow v4 codebase, so if you migrate from SpecFlow v3, you should consider the Breaking changes since SpecFlow v3 section as well.

Migrate with the Reqnroll SpecFlow Compatibility Package#

Reqnroll contains a SpecFlow Compatibility Package (Reqnroll.SpecFlowCompatibility) that allows to use the Reqnroll classes using the SpecFlow namespace (TechTalk.SpecFlow). This allows a quick migration of SpecFlow project that requires minimal code changes. Later the migrated project can be incrementally transformed to use the Reqnroll namespaces.

In order to migrate a SpecFlow project using the SpecFlow compatibility package, you need to perform the following steps.

Step 1 - Change NuGet packages#

You need to remove the SpecFlow NuGet package references from the project and replace them with the Reqnroll ones. This can be done with the Visual Studio NuGet package manager or by modifying the project file in an editor.

  • Packages to be removed:

    • any package where the name starts with SpecFlow, e.g. SpecFlow or SpecFlow.MsTest

    • the CucumberExpressions.SpecFlow.* packages (Reqnroll has built-in Cucumber Expression support)

  • Packages to add:

    • The Reqnroll package according to the test execution framework you use: Reqnroll.NUnit, Reqnroll.MsTest or Reqnroll.xUnit

    • The SpecFlow Compatibility package: Reqnroll.SpecFlowCompatibility

    • If you have used any of the SpecFlow.Actions.* package (e.g. SpecFlow.Actions.Selenium), you need to add the matching Reqnroll.SpecFlowCompatibility.Actions.* package (Reqnroll.SpecFlowCompatibility.Actions.Selenium).

After the change, your project file might look like this:

C# Project File (.csproj)#
<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <!-- test project dependencies (MsTest) -->
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
    <PackageReference Include="MSTest.TestAdapter" Version="3.2.0" />
    <PackageReference Include="MSTest.TestFramework" Version="3.2.0" />

    <!-- Reqnroll -->
    <PackageReference Include="Reqnroll.MsTest" Version="1.0.0" />
    <PackageReference Include="Reqnroll.SpecFlowCompatibility" Version="1.0.0" />
  </ItemGroup>
  [...]
</Project>

Tip

For most of the SpecFlow projects this is the only change you need to do and your project is ready to run with Reqnroll.

Step 2 - Review code compatibility#

Build the project with the changed package references. If the project builds successfully, you can move on to the next step.

If you see build errors, they might belong to one of the following categories.

  1. If the C# compiler complains of a missing TechTalk.SpecFlow.<component> namespace or a missing class, it means that the code has used some infrastructural elements of SpecFlow. For these files, simply add a namespace using for the related Reqnroll namespace: using Reqnroll.<component>. This might happen for special hook classes or step argument transformations.

  2. Any other compilation error might be caused by the breaking changes between SpecFlow v3 and v4. Please check the section Breaking changes since SpecFlow v3 below for the fixes.

After fixing these issues, your project should compile successfully.

Step 3 - Review SpecFlow App.config settings (if applicable)#

Reqnroll uses a JSON configuration file named reqnroll.json, but it is also compatible with the specflow.json configuration files. So if you have used specflow.json or have not used custom SpecFlow configuration, you can move on to the next step.

If you have used the legacy App.config file to configure SpecFlow, your configuration is also handled by the SpecFlow Compatibility package, except the configuration section declaration. So you need to change only one line in your configuration file as highlighted below.

App.config#
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="specFlow" type="Reqnroll.SpecFlowCompatibility.ReqnrollPlugin.ConfigurationSectionHandler, Reqnroll.SpecFlowCompatibility.ReqnrollPlugin" />
  </configSections>
  <specFlow>
    <language feature="hu-HU" />
    <stepAssemblies>
      <stepAssembly assembly="ExternalStepDefs" />
    </stepAssemblies>
  </specFlow>
</configuration>

Step 4 - Review execution compatibility#

Now it is time to run your tests. If the tests were passing before, they should be still passing, there is no reported compatibility issue.

If you run into any problems, it might be caused by the breaking changes between SpecFlow v3 and v4. Please check the section Breaking changes since SpecFlow v3 below for the fixes.

Congratulations you are done!

Our more complex sample application, ReqOverflow has been also migrated from SpecFlow. You can check what changes we had to do in order to get it working with Reqnroll using the SpecFlow compatibility package. See the changes on GitHub.

Migrate with namespace changes#

Thanks to the high level of compatibility, it is also easy to perform a full migration from SpecFlow projects that requires simple changes, it is mostly doable with search-and-replace.

In order to migrate a SpecFlow project, you need to perform the following steps.

Step 1 - Change NuGet packages#

You need to remove the SpecFlow NuGet package references from the project and replace them with the Reqnroll ones. This can be done using the Visual Studio NuGet package manager or by modifying the project file in an editor.

  • Packages to be removed:

    • any package where the name starts with SpecFlow, e.g. SpecFlow or SpecFlow.MsTest

    • the CucumberExpressions.SpecFlow.* packages (Reqnroll has built-in Cucumber Expression support)

  • Packages to add:

    • The Reqnroll package according to the test execution framework you use: Reqnroll.NUnit, Reqnroll.MsTest or Reqnroll.xUnit

    • If you have used any of the SpecFlow.Actions.* package (e.g. SpecFlow.Actions.Selenium), you need to add the matching Reqnroll.SpecFlowCompatibility.Actions.* package (Reqnroll.SpecFlowCompatibility.Actions.Selenium).

After the change, your project file might look like this:

C# Project File (.csproj)#
<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <!-- test project dependencies (MsTest) -->
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
    <PackageReference Include="MSTest.TestAdapter" Version="3.2.0" />
    <PackageReference Include="MSTest.TestFramework" Version="3.2.0" />

    <!-- Reqnroll -->
    <PackageReference Include="Reqnroll.MsTest" Version="1.0.0" />
  </ItemGroup>
  [...]
</Project>

Step 2 - Replace namespaces#

Now open the project in Visual Studio or in a code editor and replace all usages of the TechTalk.SpecFlow namespace to Reqnroll. This can be done with a search-and-replace operation in your editor. Make sure you perform the replace in all files (usual shortcut: Shift-Ctrl-H).

  • Search for: TechTalk.SpecFlow, enable Match case and Match whole word

  • Replace with: Reqnroll

This will replace the namespace in namespace usings (e.g. using TechTalk.SpecFlow;) or fully qualified class names (e.g. TechTalk.SpecFlow.ScenarioContext).

Step 3 - Review code compatibility#

Build the project with the changed package references. If the project builds successfully, you can move on to the next step.

If you see build errors, they might belong to one of the following categories.

  1. You might have used a SpecFlow class that had SpecFlow in the name. The most common example is ISpecFlowOutputHelper. Replace these accordingly (e.g. IReqnrollOutputHelper). If you use them extensively, you can also use a “replace in all files” function.

  2. Any other compilation error might be caused by the breaking changes between SpecFlow v3 and v4. Please check the section Breaking changes since SpecFlow v3 below for the fixes.

After fixing these issues, your project should compile successfully.

Step 4 - Migrate config settings#

If you have not used custom SpecFlow configuration, you can move on to the next step.

Reqnroll uses a JSON configuration file named reqnroll.json. The format is compatible with the specflow.json configuration file format, so the migration is simple, you just need to rename the file to reqnroll.json. It is recommended to set the JSON schema reference, so that your editor offers completion for the settings. The official schema reference is https://schemas.reqnroll.net/reqnroll-config-latest.json, which you can use like the example shows below.

reqnroll.json#
{
  "$schema": "https://schemas.reqnroll.net/reqnroll-config-latest.json",

  "language": {
    "feature": "hu-HU"
  },
  "bindingAssemblies": [
    {
      "assembly": "ExternalStepDefs"
    }
  ]
}

There are two settings in the reqnroll.json that have different name, although the names used in SpecFlow are also accepted. It is recommended though to update these as well:

  • The stepAssemblies section has been renamed to bindingAssemblies. See bindingAssemblies.

  • The bindingCulture/name setting has been moved to the language section as language/binding. See language.

If you have used the legacy App.config file to configure SpecFlow, you need to migrate the settings to reqnroll.json based on our Configuration reference.

Step 5 - Review execution compatibility#

Now it is time to run your tests. If the tests were passing before, they should be still passing, there is no reported compatibility issue.

If you run into any problems that might be caused by the breaking changes between SpecFlow v3 and v4. Please check the section Breaking changes since SpecFlow v3 below for the fixes.

Congratulations you are done!

Our more complex sample application, ReqOverflow has been also migrated from SpecFlow. You can check what changes we had to do in order to get it working with Reqnroll with a complete migration. See the changes on GitHub.

Breaking changes since SpecFlow v3#

As Reqnroll is based on SpecFlow v4, if you migrate from SpecFlow v3, you might encounter problems that are caused by the breaking changes between SpecFlow v3 and v4. The following list contains the most important breaking changes and the suggestions to resolve them.

Cucumber Expressions support, compatibility of existing expressions#

Reqnroll supports Cucumber Expressions natively for step definitions. This means that whenever you define a step using the [Given], [When] or [Then] attribute, you can either provide a regular expression for it as a parameter or a cucumber expression.

Most of your existing regex step definitions will be compatible, because they are either properly recognized as regex or the expression works the same way with both expression types (e.g. simple text without parameters).

In case your regular expression is wrongly detected as cucumber expression, you can always force to use regular expression by specifying the regex start/end markers (^/$).

[When(@"^this expression is treated as a regex$")]

There are a few special cases listed below.

Invalid expressions after upgrade#

In some cases you may see an error after upgrading to the Reqnroll. For example if you had a step definition with an attribute like:

[When(@"I \$ something")]
This Cucumber Expression has a problem ...

In this case the problem is that Reqnroll wrongly identified your expression as a cucumber expression.

Solution 1: Force the expression to be a regular expression by specifying the regex start/end markers (^/$):

[When(@"^I \$ something$")]

If you have many of such step definitions, you can force all of them to be treated as regex by including the start/end markers using Visual Studio “Find and Replace in Files” (Ctrl+Alt+H) option:

  • Set search text to \[(Given|When|Then)\((@?)"(.*?)"\)\]

  • Set replacement text to [$1($2"^$3$$")]

  • Check “Use regular expressions” setting

  • Click on “Replace All”

This will add the markers to all step definition attributes.

Solution 2: Change the expression to be a valid cucumber expression. For the example above, you need to remove the masking character (\), because the $ sign does not have to be masked in cucumber expressions:

[When("I $ something")]

Expression matching problems during test execution#

In some very special cases it can happen that the expression is wrongly identified as cucumber expression, but you only get the step binding error during test execution (usually No matching step definition found error), because the expression is valid as regex and as cucumber expression as well, but with different meaning.

For example if you had a step definition that matches the step When I a/b something, it will be considered as a cucumber expression, but in cucumber expressions, the / is used for alternation (so it matches either When I a something or When I b something).

[When(@"I a/b something")]

Solutions: You can apply the same solutions as above: either force it to be a regular expression by specifying the regex start/end markers or make it a valid cucumber expression.

For the latter case, you would need to mask the / character:

[When(@"I a\/b something")]

Cucumber Expression step definition skeletons#

Reqnroll will by default generate step definition skeletons (snippets) for the new steps. So in case you write a new step as

When I have 42 cucumbers in my belly

Reqnroll will suggest the step definition to be:

[When("I have {int} cucumbers in my belly")]
public void WhenIHaveCucumbersInMyBelly(int p0)
...

If you would like to use only regular expressions in your project, you either have to fix the expression manually, or you can configure Reqnroll to generate skeletons with regular expressions. You can achieve this with the following setting in the reqnroll.json file:

reqnroll.json#
{
  "$schema": "https://schemas.reqnroll.net/reqnroll-config-latest.json",
  "trace": {
    "stepDefinitionSkeletonStyle": "RegexAttribute"
  }
}

Removed calling other steps with string#

The SpecFlow v3 functionality of calling a step from a step like this is not available in Reqnroll (has been removed in SpecFlow v4):

Step Definition Class#
[Binding]
public class CallingStepsFromStepDefinitionSteps : Steps
{
  [Given(@"the user (.*) exists")]
  public void GivenTheUserExists(string name) { ... }

  [Given(@"I log in as (.*)")]
  public void GivenILogInAs(string name) { ... }

  [Given(@"(.*) is logged in")]
  public void GivenIsLoggedIn(string name)
  {
    Given(string.Format("the user {0} exists", name));
    Given(string.Format("I log in as {0}", name));
  }

This is not possible anymore, as the methods are now removed.

If you use this feature, you have two options:

Complete changelog of SpecFlow v4#

Breaking Changes:

  • Removed the ability to call steps from steps via string

  • Removed .NET Core 2.1 support (min .NET Core version: 3.1)

  • Removed .NET Framework 4.6.1 support (min .NET Framework version: 4.6.2)

  • Bindings declared as async void are not allowed. Use async Task instead.

Features:

  • Add an option to colorize test result output

  • Support for using Cucumber Expressions for step definitions.

  • Support Rule tags (can be used for hook filters, scoping and access through ScenarioInfo.CombinedTags)

  • Support for async step argument transformations.

  • Support for ValueTask and ValueTask binding methods (step definitions, hooks, step argument transformations)

  • Rules now support Background blocks

  • Collect binding errors (type load, binding, step definition) and report them as exception when any of the tests are executed.

Changes:

  • Existing step definition expressions detected to be either regular or cucumber expression.

  • Default step definition skeletons are generating cucumber expressions.

  • ScenarioInfo.ScenarioAndFeatureTags has been deprecated in favor of ScenarioInfo.CombinedTags. Now both contain rule tags as well.

  • AggregateExceptions thrown by async StepDefinition methods are no longer consumed; but passed along to the test host.