Code Review

Review code for quality issues, code smells, and pragmatic programming violations.

Review Modes

Mode 1: PR/Diff Review

# Get changed files
git diff --name-only <base>..HEAD
git diff <base>..HEAD

Focus only on changed lines and their immediate context.

Mode 2: Full Codebase Audit

Scan all source files, prioritizing:

1. •Entry points (main, index, app)
2. •Core business logic
3. •Frequently modified files (git log --format='%H' | head -100 | xargs -I{} git diff-tree --no-commit-id --name-only -r {} | sort | uniq -c | sort -rn)

Review Checklist

1. Code Smells (Critical)

See references/code-smells.md for full catalog.

Bloaters - Code that grows too large

• •Long Method (>20 lines)
• •Large Class (>200 lines)
• •Long Parameter List (>3 params)
• •Primitive Obsession

Object-Orientation Abusers

• •Switch Statements (replace with polymorphism)
• •Refused Bequest
• •Alternative Classes with Different Interfaces

Change Preventers

• •Divergent Change (one class, many reasons to change)
• •Shotgun Surgery (one change, many classes affected)
• •Parallel Inheritance Hierarchies

Dispensables

• •Dead Code
• •Duplicate Code
• •Lazy Class
• •Speculative Generality

Couplers

• •Feature Envy
• •Inappropriate Intimacy
• •Message Chains
• •Middle Man

2. Pragmatic Programmer Principles

DRY (Don't Repeat Yourself)

• •Duplicated logic or knowledge
• •Copy-paste code
• •Repeated magic values

Orthogonality

• •Components that should be independent but aren't
• •Changes rippling across unrelated modules

Reversibility

• •Hard-coded decisions that should be configurable
• •Vendor lock-in without abstraction

Tracer Bullets

• •Is the code testable end-to-end?
• •Are there integration points?

Good Enough Software

• •Over-engineering for unlikely scenarios
• •Premature optimization

Broken Windows

• •Commented-out code
• •TODO/FIXME without tickets
• •Inconsistent formatting

3. Security & Safety

• •Input validation
• •SQL injection risks
• •XSS vulnerabilities
• •Hardcoded secrets
• •Unsafe deserialization

4. Maintainability

• •Unclear naming
• •Missing or outdated comments
• •Complex conditionals
• •Deep nesting (>3 levels)
• •Missing error handling

Output Format

Generate CODE_REVIEW.md:

# Code Review Report

**Date**: YYYY-MM-DD
**Scope**: [PR #123 | Full Audit]
**Files Reviewed**: N

## Summary

| Severity | Count |
|----------|-------|
| Critical | X |
| Major    | X |
| Minor    | X |
| Info     | X |

## Critical Issues

### [Category]: Issue Title
**File**: `path/to/file.ts:42`
**Smell**: [Code smell name]

Description of the issue.

**Before**:
```language
// problematic code

Suggested Fix:

// improved code

Major Issues

...

Minor Issues

...

Recommendations

1. •Priority fixes
2. •Refactoring suggestions
3. •Architecture improvements

## Severity Levels

| Level | Description | Action |
|-------|-------------|--------|
| **Critical** | Security risks, bugs, data loss potential | Must fix before merge |
| **Major** | Code smells, maintainability blockers | Should fix soon |
| **Minor** | Style, minor improvements | Nice to have |
| **Info** | Suggestions, alternatives | Optional |

## Resources

- [references/code-smells.md](references/code-smells.md) - Complete catalog of code smells with examples