Roslyn Analyzer Hooks

Overview

Comprehensive Roslyn analyzer integration for dotnet-agent-harness providing real-time code analysis through agent hooks and enforced quality gates via git hooks.

Architecture

Layer 1: Agent-Level Hooks (Real-time)

• Trigger: Post-edit on .cs files
• Execution: Async with 60s timeout
• Scope: Single file analysis
• Output: JSON with violations + skill recommendations

Layer 2: Git Hooks (Commit/Push)

• pre-commit: Staged files analysis + dotnet format
• pre-push: Full solution build + tests + doc validation
• Enforcement: Blocks on errors and warnings

Configuration

Environment Variables

# Skip all analyzer checks (default: false, analyzers run by default)
export DOTNET_AGENT_HARNESS_SKIP_ANALYZERS=true

# Configure timeout (default: 60 seconds)
export DOTNET_AGENT_HARNESS_ANALYZER_TIMEOUT=120

# Minimum severity to report (Error/Warning/Info)
export DOTNET_AGENT_HARNESS_ANALYZER_SEVERITY=Warning

# Execution mode (sync/async)
export DOTNET_AGENT_HARNESS_ANALYZER_MODE=async

Project-Level (.editorconfig)

[*.cs]
# Enable all analyzers
dotnet_analyzer_diagnostic.severity = warning

# Category-based configuration
dotnet_analyzer_diagnostic.category-security.severity = error
dotnet_analyzer_diagnostic.category-performance.severity = warning

# Specific rule overrides
dotnet_diagnostic.CA2007.severity = suggestion  # ConfigureAwait
dotnet_diagnostic.CA1816.severity = error       # GC.SuppressFinalize

Analyzer Packages

Essential (Always Enabled)

• Microsoft.CodeAnalysis.NetAnalyzers - Built-in .NET analyzers
• Roslynator.Analyzers - Refactoring and code improvements
• Roslynator.CodeAnalysis.Analyzers - Code analysis rules
• Roslynator.Formatting.Analyzers - Formatting rules

Optional

• StyleCop.Analyzers - Style consistency (enable/disable via EnableStyleCop)
• Meziantou.Analyzer - Performance analyzers (EnableMeziantouAnalyzer)

CI Only (High Performance Impact)

• SonarAnalyzer.CSharp - Security and code smells (+522% build time)

Analyzer-to-Skill Routing

Analyzer Code	Skill	Description
CA2007	dotnet-csharp-async-patterns	Do not directly await a Task
CA2008	dotnet-csharp-async-patterns	TaskScheduler required
CA1816	dotnet-gc-memory	GC.SuppressFinalize
CA2000	dotnet-gc-memory	Dispose objects before losing scope
CA1822	dotnet-performance-patterns	Mark members as static
CA1860	dotnet-performance-patterns	Avoid Enumerable.Any()
CA2100	dotnet-security-owasp	SQL injection prevention
CA5350	dotnet-security-owasp	Weak cryptographic algorithms
CA1001	dotnet-architecture-patterns	IDisposable pattern
CA1063	dotnet-architecture-patterns	Implement IDisposable correctly

Full mappings in .rulesync/analyzer-to-skill.json

Git Hooks Installation

Automatic (Recommended)

# Run setup script
bash .githooks/setup.sh

Manual

# Copy hooks to .git/hooks/
cp .githooks/pre-commit .git/hooks/
cp .githooks/pre-push .git/hooks/
chmod +x .git/hooks/pre-commit .git/hooks/pre-push

Bypass Hooks

# Skip analyzer checks for this commit
DOTNET_AGENT_HARNESS_SKIP_ANALYZERS=true git commit -m "message"

# Bypass all hooks (not recommended)
git commit --no-verify -m "message"

Performance Considerations

Configuration	Build Time Impact	When to Use
NetAnalyzers only	+15%	Development (default)
+ Roslynator	+98%	Development with refactoring
+ StyleCop	+49%	Style enforcement
Full Suite (CI)	+522%	CI/CD pipelines only

Troubleshooting

Analysis Timeouts

Increase timeout:

export DOTNET_AGENT_HARNESS_ANALYZER_TIMEOUT=120

Memory Issues

For large solutions, disable heavy analyzers:

<PropertyGroup>
  <RunSonarAnalyzer>false</RunSonarAnalyzer>
</PropertyGroup>

False Positives

Disable specific rules in .editorconfig:

dotnet_diagnostic.CA1707.severity = none

References

• Roslyn Analyzer Configuration
• Performance Impact Analysis
• Analyzer-to-Skill Mappings
• Git Hooks Setup