PR Reviewer Agent

.github/README.md

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+# .github Folder - AI Coding Assistant Instructions
+
+This folder contains instructions and configurations for AI coding assistants working on the .NET MAUI repository.
+
+## Quick Start: Using the PR Reviewer Agent
+
+The PR reviewer agent conducts thorough, constructive code reviews of .NET MAUI pull requests with hands-on testing and validation.
+
+### How to Use
+
+```bash
+# Start GitHub Copilot CLI with agent support
+copilot --allow-all-tools --allow-all-paths
+
+# Invoke the pr-reviewer agent
+/agent pr-reviewer
+
+# Request a review
+please review <link to PR>
+```
+
+### Example
+
+```bash
+copilot --allow-all-tools --allow-all-paths
+/agent pr-reviewer
+please review https://github.com/dotnet/maui/pull/32372
+```
+
+## What the Agent Does
+
+Every PR review includes:
+
+1. **Code Analysis** - Reviews code for correctness, style, and best practices
+2. **Build & Deploy** - Builds the Sandbox app and deploys to simulator/emulator
+3. **Real Testing** - Tests PR changes on actual devices with measurements
+4. **Before/After Comparison** - Compares behavior with and without PR changes  
+5. **Edge Case Testing** - Tests scenarios not mentioned by the PR author
+6. **Documented Results** - Provides review with actual test data and evidence
+
+The agent will pause and ask for help if it encounters:
+- Merge conflicts when applying PR changes
+- Build errors that prevent testing
+- Test results that are unexpected or confusing
+- Any step that prevents thorough validation
+
+## Important Notes
+
+⚠️ **We're still refining the agent instructions** to ensure it consistently follows the testing workflow.
+
+**The agent will pause and ask for help if:**
+- Merge conflicts occur when applying PR changes
+- Build errors prevent testing
+- Test results are unexpected or confusing
+- Any step fails that prevents thorough validation
+
+This is by design - it's better to pause and get guidance than provide incomplete or misleading reviews.
+
+## File Structure
+
+### Agent Definitions
+- **`agents/pr-reviewer.md`** - Main PR reviewer agent instructions and workflows
+
+### Instruction Files
+These files provide specialized guidance for specific scenarios:
+
+- **`instructions/uitests.instructions.md`** - UI testing guidelines (when to use HostApp vs Sandbox)
+- **`instructions/safearea-testing.instructions.md`** - SafeArea testing patterns (measure children, not parents)
+- **`instructions/instrumentation.instructions.md`** - Code instrumentation patterns for debugging and testing
+- **`instructions/templates.instructions.md`** - Template modification rules and conventions
+
+### General Guidelines
+- **`copilot-instructions.md`** - General coding standards, build requirements, file conventions for the entire repository
+
+### Prompts
+- **`prompts/pr-reviewer.prompt.md`** - Ready-to-use prompt templates for PR reviews
+
+## For GitHub Copilot (General Development)
+
+When working on code in this repository, GitHub Copilot automatically uses:
+- `.github/copilot-instructions.md` - General coding standards
+- `.github/instructions/*.instructions.md` - Specialized instructions based on file patterns
+
+See `.github/copilot-instructions.md` for comprehensive development guidelines including:
+- Repository structure and setup
+- Build and test workflows
+- Platform-specific development
+- Contribution guidelines
+
+## Instruction Precedence
+
+When multiple instruction files exist, follow this priority order:
+
+1. **Highest Priority**: Agent-specific instructions (`.github/agents/*.md`)
+2. **Secondary**: Specialized instructions (`.github/instructions/*.instructions.md`)
+3. **General Guidance**: `.github/copilot-instructions.md`
+
+If instructions conflict, higher priority files win.
+
+## Contributing to Instructions
+
+When updating agent instructions or guidelines:
+
+1. **Keep them synchronized**: Changes to agent instructions may need corresponding updates to general instructions
+2. **Test the changes**: Verify the agent/assistant behaves as expected
+3. **Document your changes**: Update this README if you add new instruction files
+4. **Be specific**: Clear, actionable instructions work better than vague guidance
+
+## Related Documentation
+
+- **Repository root**: `AGENTS.md` - Universal guidance for all AI coding assistants
+- **Development**: `DEVELOPMENT.md` - Development environment setup
+- **Contributing**: `CONTRIBUTING.md` - Contribution guidelines
+- **Wiki**: [.NET MAUI GitHub Wiki](https://github.com/dotnet/maui/wiki) - Additional resources
+
+## Troubleshooting
+
+### GitHub Copilot CLI Issues
+
+**If you have errors with the CLI working or authentication issues:**
+
+Follow these steps to reset your authentication:
+
+```bash
+# Start Copilot CLI
+copilot
+
+# Logout from current session
+/logout
+
+# Exit Copilot CLI
+exit
+
+# Re-authenticate with GitHub
+gh auth login
+
+# Start Copilot CLI again
+copilot
+```
+
+This will refresh your GitHub authentication and resolve most CLI-related issues.
+
+### Agent Issues
+
+**Agent doesn't complete testing:**
+- Check the agent's output for error messages
+- The agent should pause and ask for help if it encounters issues
+- If it silently stops, let us know so we can improve the instructions
+
+**Build or test failures:**
+- The agent is designed to pause and ask for help rather than proceeding
+- Work with the agent to resolve the issue before continuing the review
+- This ensures reviews are based on actual working code
+
+## Support
+
+For issues or questions about the AI agent instructions:
+1. Check this README and referenced instruction files
+2. Review recent PR reviews to see examples
+3. Ask in the repository discussions or issues
+4. Propose changes via PR to improve the instructions
+
+---
+
+**Last Updated**: 2025-11-06
+
+**Note**: These instructions are actively being refined. Feedback and improvements are welcome!