manual_slop/conductor/tracks/tier4_auto_patching_20260306/plan.md

Implementation Plan: Tier 4 Auto-Patching (tier4_auto_patching_20260306)

Reference: Spec | Architecture Guide

Phase 1: Patch Generation

Focus: Generate unified diff on test failure

• Task 1.1: Initialize MMA Environment

• Task 1.2: Extend Tier 4 prompt for patch generation

  • WHERE: src/mma_prompts.py or inline in ai_client.py
  • WHAT: Prompt to generate unified diff
  • HOW:

    TIER4_PATCH_PROMPT = """
    Analyze the error and generate a unified diff patch to fix it.
    Output format:
    --- a/path/to/file.py
    +++ b/path/to/file.py
    @@ -line,count +line,count @@
     context
    -removed line
    +added line
     context
    """
    

• Task 1.3: Add patch generation function

  • WHERE: src/ai_client.py
  • WHAT: Generate patch from error
  • HOW:

    def run_tier4_patch_generation(error: str, file_context: str) -> str:
     prompt = TIER4_PATCH_PROMPT + f"\n\nError:\n{error}\n\nFiles:\n{file_context}"
     return send(prompt, model="gemini-2.5-flash-lite")
    

Phase 2: Diff Viewer UI

Focus: Display side-by-side diff

• Task 2.1: Parse unified diff

  • WHERE: src/gui_2.py or new src/diff_viewer.py
  • WHAT: Parse diff into hunks
  • HOW:

    def parse_diff(diff_text: str) -> list[dict]:
     hunks = []
     current_hunk = None
     for line in diff_text.split("\n"):
      if line.startswith("@@"):
       if current_hunk: hunks.append(current_hunk)
       current_hunk = {"header": line, "lines": []}
      elif current_hunk:
       current_hunk["lines"].append(line)
     if current_hunk: hunks.append(current_hunk)
     return hunks
    

• Task 2.2: Render diff viewer

  • WHERE: src/gui_2.py
  • WHAT: Color-coded diff display
  • HOW:

    for hunk in hunks:
     for line in hunk["lines"]:
      if line.startswith("+"):
       imgui.text_colored(vec4(100, 255, 100, 255), line)
      elif line.startswith("-"):
       imgui.text_colored(vec4(255, 100, 100, 255), line)
      else:
       imgui.text(line)
    

Phase 3: Patch Application

Focus: Apply patch with backup

• Task 3.1: Create backup before apply

  • WHERE: src/gui_2.py or src/mcp_client.py
  • WHAT: Backup file to .backup
  • HOW:

    import shutil
    backup_path = file_path.with_suffix(file_path.suffix + ".backup")
    shutil.copy(file_path, backup_path)
    

• Task 3.2: Apply patch

  • WHERE: src/gui_2.py
  • WHAT: Use patch command or difflib
  • HOW:

    import subprocess
    result = subprocess.run(["patch", "-p1"], input=diff_text, capture_output=True, text=True)
    

• Task 3.3: Restore on failure

  • WHERE: src/gui_2.py
  • WHAT: Restore from backup if patch fails
  • HOW: shutil.copy(backup_path, file_path)

Phase 4: Modal UI

Focus: Approval modal for patches

• Task 4.1: Create patch approval modal
  • WHERE: src/gui_2.py
  • WHAT: Modal with diff preview and Apply/Reject buttons
  • HOW:

    if self._show_patch_modal:
     imgui.open_popup("Apply Patch?")
    if imgui.begin_popup_modal("Apply Patch?"):
     # Render diff
     if imgui.button("Apply"):
      self._apply_current_patch()
      imgui.close_current_popup()
     imgui.same_line()
     if imgui.button("Reject"):
      imgui.close_current_popup()
     imgui.end_popup()
    

Phase 5: Testing

• Task 5.1: Write unit tests
• Task 5.2: Conductor - Phase Verification