CSharpener - C# Code Analysis

CSharpener is a Roslyn-based static analysis tool that analyzes C# codebases to build call graphs, identify unused code, and help with refactoring decisions.

Quick Start for Claude

ALWAYS use this exact command format when invoking CSharpener:

"Y:/CSharpDLLs/CSharpener/CSharpener.exe" <command> --solution "<path-to-solution>" --format console

Key Requirements:

• Use forward slashes for the executable path: Y:/CSharpDLLs/CSharpener/CSharpener.exe
• Use double quotes around paths
• Use backslashes for Windows paths in --solution parameter
• Don't search for the executable - use the path above directly

Common Commands:

• analyze --solution <path> --format console --include-call-graph - Full analysis with call graph
• unused --solution <path> --format console - Find unused methods
• callers --solution <path> --method <name> --format console - Find who calls a method
• dependencies --solution <path> --method <name> --format console - Find method dependencies
• impact --solution <path> --method <name> --format console - Analyze removal impact

Executable Location

Primary: Y:\CSharpDLLs\CSharpener\CSharpener.exe (use Y:/ with forward slashes in bash)

Fallback: If the Y: drive is not available, the source code can be built from:

• GitHub: https://github.com/lawless-m/CSharpener
• Build: dotnet build -c Release
• Output: CSharpCallGraphAnalyzer\bin\Release\net9.0\win-x64\csharp-analyzer.exe

Available Commands

1. analyze - Full Analysis

Performs comprehensive analysis including call graph, unused methods, and statistics.

Y:\CSharpDLLs\CSharpener\CSharpener.exe analyze --solution <path> --format console

Options:

• --solution, -s (required): Path to .sln or .csproj file
• --format, -f: Output format (json, console, dot, graphviz, html) [default: json]
• --output, -o: Output file path (stdout if not specified)
• --include-call-graph: Include full call graph in output [default: true]
• --exclude-namespace: Namespaces to exclude from analysis

2. unused - Find Unused Methods

Quickly scans for potentially unused methods with confidence levels.

Y:\CSharpDLLs\CSharpener\CSharpener.exe unused --solution <path> --format console

Options:

• --solution, -s (required): Path to .sln or .csproj file
• --format, -f: Output format (json, console, dot, graphviz) [default: json]
• --output, -o: Output file path
• --exclude-namespace: Namespaces to exclude

Confidence Levels:

• High: Private methods never called (safe to remove)
• Medium: Internal methods not called within assembly
• Low: Public methods (might be external API, use with caution)

3. callers - Find Who Calls a Method

Finds all methods that call a specific method.

Y:\CSharpDLLs\CSharpener\CSharpener.exe callers --solution <path> --method <method-name> --format console

Options:

• --solution, -s (required): Path to .sln or .csproj file
• --method, -m (required): Fully qualified or partial method name to search for
• --format, -f: Output format [default: json]

Example:

Y:\CSharpDLLs\CSharpener\CSharpener.exe callers -s MySolution.sln -m "BuildCallGraphAsync" -f console

4. dependencies - Find Method Dependencies

Finds all methods that a specific method calls (its dependencies).

Y:\CSharpDLLs\CSharpener\CSharpener.exe dependencies --solution <path> --method <method-name> --format console

Options:

• --solution, -s (required): Path to .sln or .csproj file
• --method, -m (required): Method name to analyze
• --format, -f: Output format [default: json]

5. impact - Analyze Removal Impact

Analyzes what would break if you removed a method (safety check before deletion).

Y:\CSharpDLLs\CSharpener\CSharpener.exe impact --solution <path> --method <method-name> --format console

Options:

• --solution, -s (required): Path to .sln or .csproj file
• --method, -m (required): Method to analyze
• --format, -f: Output format [default: json]

Shows:

• Direct callers (methods that immediately call this method)
• Transitive callers (methods that indirectly depend on it)
• Entry points affected (would break Main methods or public APIs)

6. document - Generate Documentation

Generates HTML documentation with cross-referenced code, call graphs, and navigation.

Y:\CSharpDLLs\CSharpener\CSharpener.exe document --solution <path> --output docs/analysis.html

Options:

• --solution, -s (required): Path to .sln or .csproj file
• --output, -o (required): Output HTML file path
• --include-unused: Include unused methods in documentation
• --include-tests: Include test projects

Usage Examples for Claude

Example 1: Find Unused Methods

User Request: "Find unused methods in my solution"

Claude Action:

Y:\CSharpDLLs\CSharpener\CSharpener.exe unused --solution "C:\path\to\solution.sln" --format console

Interpretation:

• High confidence = Safe to delete
• Medium confidence = Review carefully
• Low confidence = Might be public API, investigate before removing

Example 2: Analyze Impact Before Deletion

User Request: "What would break if I deleted the ProcessData method?"

Claude Action:

Y:\CSharpDLLs\CSharpener\CSharpener.exe impact --solution "C:\path\to\solution.sln" --method "ProcessData" --format console

Interpretation:

• 0 direct callers = Safe to delete
• Entry points affected > 0 = Breaking change, requires API updates
• Many transitive callers = Ripple effect, consider refactoring instead

Example 3: Find Who Uses a Method

User Request: "Who calls the BuildAsync method?"

Claude Action:

Y:\CSharpDLLs\CSharpener\CSharpener.exe callers --solution "C:\path\to\solution.sln" --method "BuildAsync" --format console

Example 4: Generate Documentation

User Request: "Generate HTML documentation for my project"

Claude Action:

Y:\CSharpDLLs\CSharpener\CSharpener.exe document --solution "C:\path\to\solution.sln" --output docs/csharpener-analysis.html

Then open the generated HTML file in a browser.

Example 5: Full Analysis

User Request: "Analyze my solution and show me statistics"

Claude Action:

Y:\CSharpDLLs\CSharpener\CSharpener.exe analyze --solution "C:\path\to\solution.sln" --format console

Performance Tips

1. First Run Creates Cache: Initial analysis is slow, subsequent runs are faster
2. Exclude Test Projects: Use --exclude-namespace "*.Tests,*.Test" for large solutions
3. Cache Location: .csharpener-cache/ in solution directory (can be deleted to force refresh)
4. Large Solutions: Analyze individual projects instead of full solution for faster results

Common Patterns

Refactoring Workflow

1. Find unused methods: unused --solution MySolution.sln
2. For each suspicious method, check impact: impact --method MethodName
3. If safe (0 callers), delete the method
4. Repeat until clean

Understanding Code Flow

1. Start with entry points: callers --method Main
2. Explore dependencies: dependencies --method ProcessRequest
3. Generate visualization: analyze --format dot (use Graphviz to render)

Code Review

1. Generate documentation: document --output review.html
2. Share HTML file with team
3. Review unused methods list together
4. Make cleanup decisions

Troubleshooting

"Solution file not found"

• Use absolute paths, not relative
• Ensure .sln or .csproj file exists
• Check for typos in path

"No methods found"

• Solution might not be building
• Try dotnet build first to ensure it compiles
• Check that it's a C# project (not F#, VB.NET, etc.)

Analysis Taking Too Long

• Exclude test projects with --exclude-namespace
• Analyze smaller projects first
• Check for large auto-generated code files

"Method not found" in callers/dependencies

• Use partial names (e.g., "BuildAsync" instead of full qualified name)
• Method name is case-insensitive
• Try shortening the method name

Output Formats

• console: Human-readable output for terminal
• json: Machine-readable for scripting/automation
• html: Interactive documentation (document command only)
• dot: Graphviz format for visualization
• graphviz: Same as dot

Integration with CI/CD

# Example GitHub Actions workflow
- name: Analyze for unused code
  run: |
    Y:\CSharpDLLs\CSharpener\CSharpener.exe unused \
      --solution MySolution.sln \
      --format json \
      --output unused-methods.json

- name: Upload results
  uses: actions/upload-artifact@v3
  with:
    name: code-analysis
    path: unused-methods.json

Notes

• CSharpener uses Roslyn for analysis (same as Visual Studio)
• Detects reflection usage and warns about false positives
• Recognizes DI patterns (AddTransient, AddScoped, etc.)
• Thread-safe and can be run in parallel on different solutions
• Cache is solution-specific and invalidates on file changes

Support

• GitHub: https://github.com/lawless-m/CSharpener
• Issues: https://github.com/lawless-m/CSharpener/issues