Patch edit

Spec §20.3 / §21.3.2: code-migration / tune-collab cannot ship a trustworthy diff when the agent rewrites whole files in one pass — the reviewer can't audit the change. This atom enforces "one step per turn, smallest possible localised edit".

Inputs

• plan/steps.json from rewrite-plan.
• The current value of iterations (the daemon's per-stage counter).
• code/index.json for the file's known imports + neighbours.

Output

The atom mutates files inside the project cwd via the file-edit tool. After every iteration, it writes a per-step receipt:

project-cwd/
└── plan/
    ├── steps.json (status updated: 'pending' → 'completed' | 'skipped')
    └── receipts/
        └── step-<id>.json    # { files: ['...'], diffSummary, rationale, completedAt }

Convergence

The atom completes when every step in plan/steps.json is in a terminal state (completed / skipped) OR iterations >= OD_MAX_DEVLOOP_ITERATIONS. Use:

{
  "id": "patch-edit-loop",
  "atoms": ["patch-edit"],
  "repeat": true,
  "until": "plan.steps.terminal === plan.steps.total || iterations >= 8"
}

Anti-patterns the prompt fragment forbids

• Rewriting an entire file when the rewrite-plan step is localised.
• Touching a file outside the step's files[].
• Touching a shell-tier file when the step's risk is not 'high' or the user hasn't confirmed.
• Skipping a step without a receipt + a rationale string.

Status

Implemented by the daemon runner in apps/daemon/src/plugins/atoms/patch-edit.ts. It validates step ownership and risk, applies unified diffs with atomic writes, and records receipts and progress.