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JavaScript Code Review Guide

The most common JavaScript bugs, security vulnerabilities, and code quality issues — with real examples, secure fixes, and AI-powered detection. Covers Node.js, React, and vanilla JS.

What is JavaScript code review?

JavaScript code review examines JS source code to find bugs, security vulnerabilities, and style issues before they reach production. Because JavaScript is loosely typed and runs in both browser and server environments, it has a unique set of failure modes.

What AI finds that manual review misses

Prototype pollution, ReDoS from catastrophic regex backtracking, and CSRF via missing SameSite cookie attributes. LearnCodeGuide uses GPT-4o + Claude Sonnet in parallel to catch issues from both perspectives.

Security Vulnerabilities

3 guides
Security

XSS in JavaScript

Security

SQL Injection in JavaScript

Security

CSRF in JavaScript

Common Bugs

6 guides
Bug

Undefined Errors

Bug

Async/Await Mistakes

Bug

Closure Bugs

Bug

this Context Bugs

Bug

Hoisting Bugs

Bug

Equality Operator Bugs

Code Quality

6 guides
Code Quality

Callback Hell

Code Quality

Dead Code

Code Quality

Duplicate Code

Code Quality

Long Functions

Code Quality

Magic Numbers

Tool

JS Bug Detector

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Published by LearnCodeGuide Team · Last reviewed: October 2025