Activation Contract
Load this skill when a planned PR may exceed 400 changed lines, an ODD feature's forecast or running authored changed-line count from work-unit commits exceeds about 400, or the user asks for chained/stacked PRs, review slices, or reviewer-load control.
Hard Rules
- Split PRs over 400 changed lines unless a maintainer explicitly accepts
size:exception. - The budget constrains how work is sliced, never the code itself. Never delete comments, blank lines, docs, or tests, and never compress or restyle code, to fit under the budget.
- Slicing is bounded: make one honest slicing pass. If no cohesive split brings every slice within budget, stop iterating, keep the best cohesive split, and report the final line count with a
size:exception recommendation. - Keep each PR reviewable in about ≤60 minutes.
- Use one deliverable work unit per PR; keep tests/docs with the unit they verify.
- State start, end, prior dependencies, follow-up work, and out-of-scope items in every chained PR.
- Every child PR must include a dependency diagram marking the current PR with
📍. - In Feature Branch Chain, create a draft/no-merge tracker PR; child PR #1 targets the tracker branch, later children target the immediate parent branch.
- Treat polluted diffs as base bugs: retarget or rebase until only the current work unit appears.
- Do not mix chain strategies after the user chooses one.
Decision Gates
| Condition | Action |
|---|
| PR ≤400 changed lines and focused | Keep single PR. |
| PR >400, each slice can land independently | Use Stacked PRs to main. |
| PR >400, feature must integrate before main | Use Feature Branch Chain with tracker. |
| Generated/vendor/migration diff cannot split cleanly | Ask maintainer for size:exception. |
| No cohesive split fits the budget after one slicing pass | Stop; deliver the best split, report the overage and why it cannot shrink further, and recommend size:exception. |
ODD provides delivery_strategy and chain_strategy | Follow them before the next work-unit commit or PR creation. |
Execution Steps
- Estimate changed lines and identify independent work units.
- Ask for a chain strategy when none is cached and the budget is exceeded.
- Create branches/PRs using the chosen strategy only.
- Add Chain Context to each PR without replacing the repo PR template.
- Verify each PR independently: CI/tests/docs/manual checks, rollback scope, and clean diff.
- Keep tracker PR draft/no-merge until all child PRs are reviewed and integrated.
Output Contract
Return the chosen strategy, PR order, current PR boundary, dependency diagram, review budget (additions + deletions), verification plan, and any size:exception rationale.
References
