feature-port-doc-generator

Feature Porting Document Generator

Core Approach

Not copying code — transmitting intent. Let the receiving team understand "what changed, why it changed, and how to implement it in their own project."

When to Use

• User provides a commit ID that needs to be documented as a porting guide
• User provides one or more changed files and needs to extract the change intent
• A feature implementation needs to be shared with other project teams

Workflow

Phase 1: Get Change Information

Case A: User provided a commit ID

1. Get commit basic info (message, author, time)
2. Get commit code diff
3. Count changed files, assess change scope

Case B: User specified file paths (no commit ID)

1. Read the user-specified file contents
2. Find recent related commit history for those files
3. Confirm the relevant commits and get their diffs

Phase 2: Analyze Change Intent

1. [Change type] What kind of change is this? (New feature / Bug fix / Performance optimization / Refactoring)
2. [Problem/Goal] What problem does this change solve, or what goal does it achieve?
3. [Change scope] Which files are involved? What's the purpose of each file's change?
4. [Core logic] What's the key behavioral change (not code change)?
5. [External dependencies] Does the change introduce new dependencies (npm packages, utility functions, components, APIs)?
6. [Porting prerequisites] What baseline conditions must other projects meet before porting?

Phase 3: Collect File Paths

1. For file paths in the commit diff, combine with project root to form absolute paths
2. Use git rev-parse --show-toplevel to get the project root
3. All file paths in the final document should use absolute path format

Phase 4: Assess Porting Complexity

Complexity	Criteria	Porting advice
Simple	Single file change, no new dependencies, independent logic	Can directly reference code implementation
Medium	Multi-file change, few dependencies, related logic	Port file by file in order
Complex	Involves architectural changes, many dependencies, requires prerequisite work	Port in phases

Phase 5: Generate Porting Document

The document must include these sections:

• Change overview (type, goal, background)
• File scope (file list + change description)
• Core logic explanation (before/after behavior comparison)
• Dependency list (new dependencies, prerequisites)
• Porting steps (step-by-step instructions)
• Notes (common issues, risk points)

---

Output Format

## [Feature Name] Porting Document

### Change Overview

- **Type**: New feature / Bug fix / Performance optimization / Refactoring
- **Goal**: [One-sentence description]
- **Background**: [Why this change was needed]

### File Scope

| File path           | Change description  |
| ------------------- | ------------------- |
| /abs/path/file1.ts  | [Purpose of change] |
| /abs/path/file2.tsx | [Purpose of change] |

### Core Logic Explanation

**Before**: [Original behavior]

**After**: [New behavior]

### Dependency List

**New dependencies**:

- [Dependency package/utility function/component]

**Prerequisites**:

- [Baseline conditions the project must meet]

### Porting Steps

1. [Step 1: specific action]
2. [Step 2: specific action]
3. [Step 3: specific action]

### Notes

- [Risk point or common issue]

---

Important Notes

• Paths must be absolute — All file paths in the document must use absolute paths
• Intent over code — The core of the document is communicating "why it changed"
• Reader's perspective — Write for someone who doesn't know the original project
• Dependencies must be complete — All newly introduced dependencies must be listed
• Steps must be executable — Porting steps must be specific enough to follow