Change Pack

Generate a complete Git writing pack (Branch Name + Commit Message + PR Content) from one shared diff context.

Why this skill exists: Reading and analyzing diffs is expensive (tokens + time). This skill reads the diff once, builds a shared context, then generates all three outputs from that same context. Much more efficient than calling three separate skills.

PR Title and PR Description are output as separate copy-ready blocks because GitHub has two different input fields.

Context Reuse (Step 0)

See _shared/context-reuse.md for the context reuse protocol.

If DIFF_CONTEXT or RAW_DIFF is already provided, use it directly to save time and tokens.

Build Shared DIFF_CONTEXT (Step 1)

See _shared/branch-diff-gathering.md for branch diff collection details.

Use branch-level diff as primary source (compare current branch against base branch).

Build one compact DIFF_CONTEXT containing:

• base_branch and effective diff range (for traceability)

• change scope (major modules/files)

• primary intent (feat|fix|refactor|docs|chore|test|perf )

• key behavior changes (what + why)

• notable risks/compatibility impact

• optional issue references if explicitly provided

• domain keywords (terms ) for naming consistency

Why build DIFF_CONTEXT:

• Single source of truth for all three outputs

• Avoids re-reading the same diff three times

• Ensures consistency across branch name, commit, and PR

• Keeps token usage reasonable (≤ 220 lines recommended)

Fallback behavior:

• If branch diff is empty, stop and ask user to confirm target base branch

• If current branch equals base but no upstream tracking, ask for explicit comparison ref

• If user explicitly asks to include uncommitted work, append working tree deltas and mark source: mixed

Chain Generation from DIFF_CONTEXT (Step 2)

Use the same DIFF_CONTEXT as single source of truth. Do not re-read full diff in downstream steps.

2.1 Branch Name

Generate 3 candidates: one recommended + two alternatives.

Use format <prefix>/<slug> (e.g., feat/user-auth , fix/token-race ).

Keep best candidate ≤ 48 chars preferred (hard max 63 due to filesystem limits).

2.2 Commit Message

Generate Conventional Commits output:

• required Header: type(scope): subject

• optional Body and Footer

Keep header ≤ 72 chars (Git tools truncate longer headers).

English subject starts with lowercase (Conventional Commits spec requirement).

2.3 PR Content

Generate Title

• Description in Markdown.

Type-driven sections with fixed headings (see _shared/pr-heading-map.md).

Why fixed headings: Consistent headings help teams quickly scan PRs and automated tools parse descriptions reliably.

Keep claims grounded in DIFF_CONTEXT facts.

Quick reference:

Type: feat

• 中文: ### 概述 → ### 改动说明 → ### 使用方式

• English: ### Summary → ### Changes → ### Usage

Type: fix

• 中文: ### 问题描述 → ### 复现步骤 (optional) → ### 修复方式 → ### 测试说明

• English: ### Problem → ### Steps to Reproduce (optional) → ### Solution → ### Testing

Type: perf|refactor

• 中文: ### 概述 → ### 改动说明 → ### 效果 (optional)

• English: ### Summary → ### Changes → ### Impact (optional)

Type: docs|chore

• 中文: ### 概述 → ### 改动说明

• English: ### Summary → ### Changes

Output Consistency

Branch prefix, commit type, and PR title type should be semantically aligned with intent whenever possible. This creates a coherent story across all three artifacts.

Reuse terms from DIFF_CONTEXT.terms to avoid wording drift between outputs.

Language Behavior (Step 3)

See _shared/bilingual-output.md for bilingual output rules.

Default: Simplified Chinese + English (semantically aligned, not word-for-word translation).

If user requests one language, output only requested language.

When bilingual, Chinese and English must each be wrapped in independent code blocks in every section.

Token-Efficiency Constraints (Step 4)

• Prefer git diff --stat

• targeted excerpts over massive full-file dumps

• Summarize raw diff once; downstream sections consume only DIFF_CONTEXT

• Keep internal DIFF_CONTEXT concise (recommended ≤ 220 lines equivalent text)

• Avoid duplicate explanations across branch/commit/PR outputs

Final Output Format (Step 5)

Output in order:

• Branch Name

• Commit Message

• PR Title

• PR Description

PR Title and PR Description are in two separate code blocks for direct paste into different GitHub input fields.

For each section, provide bilingual or single-language content based on request.

In bilingual mode, each section contains exactly two copy-ready code blocks (one for 中文 , one for English ).

Language label line (中文 / English ) appears immediately above its corresponding code block.

Copy-Ready Template

Branch Name

中文

Recommended: <prefix/slug> Alternatives:

• <prefix/slug-2>
• <prefix/slug-3>

English

Recommended: <prefix/slug> Alternatives:

• <prefix/slug-2>
• <prefix/slug-3>

Commit Message

中文

<type(scope): subject>

• <what + why>
• <what + why>

English

<type(scope): subject>

• <what + why>
• <what + why>

PR Title

中文

<type: brief description>

English

<type: brief description>

PR Description

中文

<fixed-section-heading>

• <fact>

English

<fixed-section-heading>

• <fact>

Example (End-to-End)

Input (context provided once):

DIFF_CONTEXT

• source: staged
• files: src/auth/token.ts, src/auth/refresh.ts, tests/auth/refresh.test.ts
• intent: fix
• highlights:
  • serialize token refresh requests to prevent concurrent overwrite
  • add retry guard for 401 edge case
  • add regression tests for refresh race
• terms: auth, token, refresh, race

Expected chained output:

Branch Name

中文

Recommended: fix/auth-token-refresh-race Alternatives:

• fix/auth-refresh-lock
• test/auth-refresh-race-coverage

English

Recommended: fix/auth-token-refresh-race Alternatives:

• fix/auth-refresh-lock
• test/auth-refresh-race-coverage

Commit Message

中文

fix(auth): 修复 token 刷新竞态

• 串行化 refresh 请求，避免并发覆盖有效 token。
• 为 401 重试边界场景补充回归测试。

English

fix(auth): handle token refresh race

• serialize refresh requests to avoid concurrent token overwrite.
• add regression tests to lock behavior for 401 retry edge cases.

PR Title

中文

fix: 防止认证 token 刷新竞态

English

fix: prevent auth token refresh race

PR Description

中文

问题描述

• 并发 refresh 请求可能覆盖有效 token。

修复方式

• 串行化 refresh 流程，并为 401 边界场景增加重试保护。

测试说明

• 增加 refresh 竞态场景的回归测试。

English

Problem

• concurrent refresh requests could overwrite valid tokens.

Solution

• serialize refresh flow and add retry guard for 401 edge cases.

Testing

• add regression tests for refresh race scenarios.

Before Finalizing (Step 6)

Quick verification:

• All sections generated from one shared DIFF_CONTEXT (no repeated full-diff reads)

• Branch prefix, commit type, and PR title type are semantically aligned with intent

• PR description headings follow the type-specific map (see _shared/pr-heading-map.md)

• In bilingual mode, each section uses independent code blocks for each language

• Statements are factual and grounded in DIFF_CONTEXT only

If something doesn't look right, adjust and regenerate only the failing section(s).

Conventions

• Do not fabricate details outside provided diff context

• Prefer domain terms from file paths/symbols (maintains consistency with codebase)

• Optimize for clarity and token efficiency by reusing one shared context