Feature Highlighter

A lightweight Visual Studio extension that provides syntax highlighting only for Gherkin/Cucumber .feature files.

What It Does

Feature Highlighter brings beautiful, accurate syntax highlighting to your BDD feature files with a custom Gherkin parser inspired by Reqnroll. It supports multiple languages automatically (English, German, French, Spanish, and more).

This extension focuses on one thing: making your feature files easier to read with proper syntax coloring.

What It Does NOT Do

This extension is intentionally minimal and does NOT include:

• ❌ Test generation or execution
• ❌ IntelliSense or autocomplete
• ❌ Step definition navigation
• ❌ Step binding detection
• ❌ Refactoring tools
• ❌ Code actions or quick fixes

If you need these features, consider using the full SpecFlow or Reqnroll extensions instead.

Features

Syntax Elements Highlighted

• Keywords - Feature, Scenario, Given, When, Then, And, But, Background, Rule, Examples (Blue, Bold)
• Comments - Lines starting with # (Green, Italic)
• Tags - @tagname (Light Blue/Cyan)
• Parameters - <parameter>, {parameter}, "string", 'string' (Light Green)
• Doc Strings - Triple quotes """ content """ (Tan/Brown)
• Tables - Pipe-delimited data tables with cell highlighting (Yellow-ish)

Multi-Language Support

With a custom Gherkin parser inspired by the Reqnroll project, keywords are automatically recognized in multiple languages:

• 🇬🇧 English: Feature, Scenario, Given, When, Then
• 🇩🇪 German: Funktionalität, Szenario, Angenommen, Wenn, Dann
• 🇫🇷 French: Fonctionnalité, Scénario, Soit, Quand, Alors
• 🇪🇸 Spanish: Característica, Escenario, Dado, Cuando, Entonces
• And more!

Installation

From VSIX File

1. Download the latest .vsix file from the Releases page
2. Double-click the .vsix file
3. Follow the Visual Studio installer prompts
4. Restart Visual Studio

From Visual Studio Marketplace

1. Open Visual Studio 2022
2. Go to Extensions → Manage Extensions
3. Search for "Feature Highlighter"
4. Click Download and restart Visual Studio

Requirements

• Visual Studio 2022 (version 17.0 or higher)
• .NET Framework 4.8

Usage

Just open any .feature file in Visual Studio 2022, and syntax highlighting will be automatically applied!

Customizing Colors

You can customize the colors used for highlighting:

1. Go to Tools → Options → Environment → Fonts and Colors
2. In the "Display items" list, look for entries starting with "Gherkin":
   • Gherkin Keyword
   • Gherkin Comment
   • Gherkin Tag
   • Gherkin Parameter
   • Gherkin Doc String
   • Gherkin Table Cell
   • Gherkin Table Pipe
3. Change the colors to your preference
4. Click OK to apply

Example

Here's what a highlighted feature file looks like:

# This is a comment
@smoke @regression
Feature: User Authentication
  As a user
  I want to log in to the system
  So that I can access my account

  Background:
    Given the application is running

  Scenario: Successful login with valid credentials
    Given I am on the login page
    When I enter username "john.doe" and password "secret123"
    And I click the login button
    Then I should see the dashboard
    And I should see a welcome message "Welcome, John!"

  Scenario Outline: Login with different credentials
    Given I am on the login page
    When I enter username "<username>" and password "<password>"
    Then I should see <result>

    Examples:
      | username  | password  | result           |
      | john.doe  | secret123 | dashboard        |
      | jane.doe  | pass456   | dashboard        |
      | invalid   | wrong     | error message    |

  Rule: Password security

    Scenario: Password requirements
      Given I am creating a new account
      When I enter a password with {min_length} characters
      Then the system should accept the password
      """
      Passwords must be at least 8 characters long
      and contain at least one number and one special character
      """

Building from Source

Prerequisites

• Visual Studio 2022 with the following workloads:
  • .NET desktop development
  • Visual Studio extension development

Build Steps

# Clone the repository
git clone https://github.com/markdav-is/Feature-Highlighter.git
cd Feature-Highlighter

# Open in Visual Studio 2022
start FeatureHighlighter.sln

# Or build from command line
msbuild FeatureHighlighter.sln /p:Configuration=Release

Testing the Extension

1. Open the solution in Visual Studio 2022
2. Press F5 to launch the Experimental Instance
3. In the Experimental Instance, open a .feature file
4. Verify that syntax highlighting is applied correctly

Creating a VSIX Package

1. Build the solution in Release configuration
2. The .vsix file will be in FeatureHighlighter/bin/Release/FeatureHighlighter.vsix

Architecture

The extension uses the Visual Studio Editor extensibility model:

• Content Type Definition - Registers .feature files as "gherkin" content type
• Classification Definitions - Defines logical token types (keyword, comment, tag, etc.)
• Format Definitions - Defines visual styles (colors, fonts) for each token type
• Classifier - Analyzes text and assigns classification types to text spans
• Parser Wrapper - Uses Reqnroll's Gherkin parser for accurate tokenization

Credits and Acknowledgments

This extension uses the Reqnroll Gherkin parser (BSD-3-Clause license) for robust, standards-compliant parsing of Gherkin syntax.

Special thanks to:

• The Reqnroll team for inspiring the multi-language Gherkin keyword support and providing an excellent open-source BDD framework
• The SpecFlow team for pioneering .NET BDD tooling
• The Cucumber community for the Gherkin language specification

License

This project is licensed under the MIT License - see the LICENSE file for details.

This extension uses a custom Gherkin parser implementation with no external parsing library dependencies.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Contribution Guidelines

1. Keep the extension focused on syntax highlighting only
2. Follow the existing code style
3. Test with multiple language variants (English, German, French, etc.)
4. Ensure performance is good for large files
5. Update documentation as needed

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions

Changelog

Version 1.1.0

• ✅ Removed unused Gherkin and Reqnroll package dependencies
• ✅ Implemented custom self-contained Gherkin parser
• ✅ Reduced package size (~125 KB)
• ✅ Improved performance with fewer dependencies

Version 1.0.0 (Initial Release)

• ✅ Syntax highlighting for all Gherkin elements
• ✅ Multi-language keyword support
• ✅ Support for parameters, tags, comments, doc strings, and tables
• ✅ Optimized for Visual Studio 2022 Dark Theme
• ✅ Lightweight and performant

Roadmap

Potential future enhancements (while keeping the extension focused on highlighting):

• Light theme color optimization
• Additional language support
• Performance improvements for very large files
• User-configurable color themes

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Made with ❤️ for the BDD community