# Git Commit Analysis Reference

## Git Commands Reference

### Basic Commit Inspection

```bash
# View commit summary
git show <hash> --stat

# View full diff
git show <hash>

# View commit message
git log -1 <hash> --pretty=format:"%s%n%n%b"

# View specific file in commit
git show <hash>:path/to/file

# View file before commit
git show <hash>^:path/to/file

# Compare with parent commit
git diff <hash>^..<hash>
```

### Advanced Inspection

```bash
# View commit with context
git show <hash> -U10  # 10 lines of context

# View only specific file changes
git show <hash> -- path/to/file

# View commit tree
git show <hash> --name-status

# View commit with word diff
git show <hash> --word-diff
```

## Analysis Depth Levels

### Level 1: Surface Analysis
- Read commit message
- List changed files
- Summarize changes

### Level 2: Code Analysis
- Read changed code sections
- Understand what changed
- Identify patterns

### Level 3: Deep Analysis (This Skill)
- Read surrounding context
- Understand why changes were made
- Analyze design decisions
- Assess impact

## Code Reading Strategies

### Strategy 1: Top-Down
1. Read function/class definition
2. Read callers
3. Read implementation details

### Strategy 2: Bottom-Up
1. Read changed code
2. Read related functions
3. Understand overall pattern

### Strategy 3: Context-First
1. Read 50-100 lines before change
2. Read changed section
3. Read 50-100 lines after change
4. Understand full context

## Common Change Patterns

### Pattern: Variable Rename
- Usually simple but check all usages
- May indicate semantic change

### Pattern: Function Extraction
- Check if extracted function is reused
- Understand abstraction level

### Pattern: Condition Addition
- What edge case is being handled?
- Why wasn't it handled before?

### Pattern: Data Structure Change
- Performance implications?
- API compatibility?

## Analysis Questions Checklist

For each change, ask:

### What Changed?
- [ ] What code was modified?
- [ ] What files were affected?
- [ ] What functions/classes changed?

### Why Changed?
- [ ] What problem does this solve?
- [ ] What requirement drives this?
- [ ] What bug was fixed?

### How Changed?
- [ ] What approach was used?
- [ ] Why this approach vs alternatives?
- [ ] What trade-offs were made?

### Impact?
- [ ] Does this break existing code?
- [ ] Are tests updated?
- [ ] Is documentation needed?
- [ ] Performance implications?

## Code Context Guidelines

### Minimum Context
- **Function changes**: Include entire function
- **Class changes**: Include class definition
- **File-level**: Include imports and related functions

### Recommended Context
- **50-100 lines** before change
- **50-100 lines** after change
- **Related functions** in same file
- **Callers** of changed functions

### Extended Context (when needed)
- **Related files** that interact
- **Similar patterns** in codebase
- **Historical context** (previous commits)

## Output Quality Standards

### Code Snippets
- ✅ Include line numbers
- ✅ Show sufficient context (50-100 lines)
- ✅ Highlight key changes
- ✅ Include both before/after

### Analysis Depth
- ✅ Explain "why" not just "what"
- ✅ Cover business and technical aspects
- ✅ Identify potential issues
- ✅ Suggest improvements if relevant

### Structure
- ✅ Clear sections and subsections
- ✅ Use emojis for visual organization
- ✅ Code blocks properly formatted
- ✅ Links to related code when helpful