jusjinuk/code-review

Code Explanation & Review

When to use

• User pastes code in the conversation
• User asks "what does this do?", "review this", "is this correct?"
• User shares a file path or GitHub link for review

Workflow

1. Identify context: language, framework, what part of a system this is
2. Read the code carefully before commenting — understand intent first
3. Explain at the right level: match the user's apparent expertise
   • For "what does this do?" — explain the high-level purpose and flow
   • For "review this" — focus on issues and improvements

What to look for

Correctness

• Logic errors, off-by-one, wrong comparisons
• Missing error handling for operations that can fail (I/O, network, parsing)
• Race conditions in async/concurrent code
• Incorrect types or unchecked type assertions

Performance (only flag if impactful)

• O(n²) or worse in hot paths (loops within loops on large data)
• Repeated computation that should be cached
• Synchronous I/O blocking the event loop
• N+1 query patterns

Security (always flag)

• SQL injection, command injection, XSS
• Hardcoded secrets or credentials
• Missing input validation at system boundaries

Style (mention briefly, don't belabor)

• Naming that obscures intent
• Overly complex logic that could be simplified
• Dead code or unused imports

Formatting for Slack

• Lead with a one-sentence summary: "This is a [description]. It [does X]."
• Group issues by severity — bugs first, then performance, then style
• For each issue: quote the problematic line, explain why it's wrong, show the fix
• Keep it concise — 3-5 observations is better than 15 nitpicks
• If the code is good, say so — don't manufacture issues