MCP Pyrefly

Instructions

Implementation Reference

• src/mcp_pyrefly/server.py:373-458 (handler)

  The implementation of the 'suggest_fix' MCP tool, which provides actionable suggestions for common Python errors based on error messages.

  async def suggest_fix(
      error_message: str,
      code_context: str | None = None,
      context: Context | None = None,
  ) -> dict[str, Any]:
      """
      Suggest fixes for common Python errors based on error messages.
  
      Analyzes error messages and provides actionable suggestions.
      """
      suggestions = []
  
      error_lower = error_message.lower()
  
      # Type error suggestions
      if "expected" in error_lower and "got" in error_lower:
          suggestions.append("Check the types of arguments being passed to functions")
          suggestions.append(
              "Consider adding type annotations to make expectations clear"
          )
  
      # Name error suggestions
      if "undefined name" in error_lower or "name error" in error_lower:
          # Extract the name if possible
          import re
  
          match = re.search(r"'(\w+)'", error_message)
          if match:
              name = match.group(1)
              # Check for similar names
              similar = session_tracker.similar_names.get(name, set())
              existing = [n for n in similar if n in session_tracker.identifiers]
              if existing:
                  suggestions.append(
                      f"Did you mean '{existing[0]}'? (found similar identifier)"
                  )
              else:
                  suggestions.append(f"Make sure '{name}' is defined before use")
                  suggestions.append("Check for typos in the identifier name")
  
      # Import error suggestions
      if "import" in error_lower:
          suggestions.append("Verify the module is installed: pip install <module>")
          suggestions.append("Check the import path is correct")
          suggestions.append("Ensure you're using the correct Python environment")
  
      # Attribute error suggestions
      if "attribute" in error_lower:
          suggestions.append(
              "Verify the object has the attribute you're trying to access"
          )
          suggestions.append("Check the object type matches your expectations")
          suggestions.append("Look for typos in the attribute name")
  
      # Indentation error suggestions
      if "indent" in error_lower:
          suggestions.append("Check that all code blocks are properly indented")
          suggestions.append("Ensure consistent use of spaces (not tabs)")
          suggestions.append("Verify indentation matches the logical structure")
  
      # Always add principled coding reminders
      principled_approach = [
          "",
          "=== PRINCIPLED CODING APPROACH ===",
          "🎯 Before implementing a fix:",
          "1. UNDERSTAND why this error happened - don't just make it go away",
          "2. CONSIDER if this reveals a design flaw that needs addressing",
          "3. CHECK for similar issues that might exist elsewhere",
          "4. IMPLEMENT a robust solution, not a quick hack",
          "5. DOCUMENT your fix so others understand the reasoning",
          "",
          "⚡ Remember: The path of least resistance often leads to technical debt!",
          "💡 Ask yourself: 'Am I fixing the symptom or the disease?'",
      ]
  
      return {
          "error": error_message,
          "suggestions": (
              suggestions
              if suggestions
              else ["No specific suggestions available for this error"]
          ),
          "has_suggestions": len(suggestions) > 0,
          "principled_approach": principled_approach,
      }