/chained-pr

name: gentle-ai-chained-pr
description: "Trigger: PRs over 400 lines, stacked PRs, review slices. Split oversized changes into chained PRs that protect review focus."
license: Apache-2.0
metadata:
  author: gentleman-programming
  version: "1.0"

Activation Contract

Load this skill when a planned PR may exceed **400 changed lines**, SDD forecasts `400-line budget risk: High` or `Chained PRs recommended: Yes`, 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`.
• 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`. | | SDD provides `delivery_strategy` | Follow it before apply/PR creation. |

Execution Steps

1. Estimate changed lines and identify independent work units. 2. Ask for a chain strategy when none is cached and the budget is exceeded. 3. Create branches/PRs using the chosen strategy only. 4. Add Chain Context to each PR without replacing the repo PR template. 5. Verify each PR independently: CI/tests/docs/manual checks, rollback scope, and clean diff. 6. 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

• [references/chaining-details.md](references/chaining-details.md) — strategy diagrams, PR body section, branch commands, and reviewer guidance.