PR Reviewer — AI-Powered Code Diff Analyser

PR Reviewer is a zero-friction AI code review tool built for the IBM Bob 2.0 Hackathon. THE PROBLEM Code reviews are slow, inconsistent, and error-prone — especially under time pressure. Developers reviewing their own PRs regularly miss security vulnerabilities, forget to write tests, and leave vague commit messages. Manual review doesn't scale. THE SOLUTION PR Reviewer lets you paste any raw git diff directly into a single web page — no GitHub login, no OAuth setup, no API tokens to configure. Hit submit, and Gemini 2.5 Flash analyses the diff and returns a structured three-section report: ⚠️ Risky / Breaking Changes — catches security flaws, signature bypasses, logic bugs, and breaking API changes 🧪 Missing Test Coverage — identifies untested code paths and new functions with no corresponding tests 📝 Unclear / Missing Commit Messages — flags vague, generic, or missing commit descriptions In our demo, the tool correctly caught a JWT decode signature bypass, a plaintext password comparison vulnerability, and a login function that always returned success — all explained clearly with no false positives. HOW IT WORKS The frontend is a single Next.js 15 App Router page with a textarea and a submit button. On submit, the diff is sent to a server-side API route (/api/review) which constructs a structured prompt and calls the Gemini 2.5 Flash API. The response is parsed into three labelled sections and rendered as bulleted result cards. The page includes a light/dark theme toggle with smooth gradient transitions. BUILT WITH IBM BOB 2.0 The entire project was designed and built using IBM Bob 2.0 as the AI coding assistant — from architecture planning in Plan mode (3 sub-tasks: scaffold, API route, UI) to full code generation in Agent mode. Bob autonomously resolved Next.js version vulnerabilities, handled gitignore conflicts during scaffolding, and iterated on the UI in real time. No code was written by hand. TECH STACK - Next.js 15 (App Router, TypeScript) - Tailwind CSS v3 - Google Gemini 2.5 Flash (@google/generative-ai) - Node.js server-side API route