MattEland.CodeReview

An LLM-powered code review tool that analyzes git diffs for C# and SQL codebases, detecting logic errors, performance issues, and security vulnerabilities that traditional static analysis tools miss.

Features

• Git Diff Analysis: Analyze changes between your current branch and a base branch (defaults to main)
• Multi-Language Support: Specialized rules for C# and SQL
• Hierarchical Rule System: Rules organized by language, category, and specific issue type
• Multiple AI Providers: Supports Azure OpenAI, OpenAI, and Ollama via Microsoft.Extensions.AI
• Extensible Prompts: Built-in rules plus user-defined .prompt files loaded at runtime
• Cross-Platform Desktop App: Uno Platform-based UI for Windows, macOS, and Linux
• CLI Tool: Command-line interface for CI/CD integration

Project Structure

CodeReviewTool/
├── src/
│   ├── MattEland.CodeReview.Core/      # Shared business logic
│   ├── MattEland.CodeReview.Cli/       # Command-line interface
│   └── MattEland.CodeReview.Desktop/   # Uno Platform desktop app
├── tests/
│   └── MattEland.CodeReview.Core.Tests/
├── prompts/                             # Hierarchical .prompt files
│   ├── csharp/
│   │   ├── security/
│   │   ├── performance/
│   │   └── logic/
│   └── sql/
│       ├── performance/
│       ├── security/
│       └── transactions/
└── docs/
    └── adr/                             # Architectural Decision Records

Getting Started

Prerequisites

• .NET 10 SDK
• One of the following AI providers:
  • Azure OpenAI subscription
  • OpenAI API key
  • Ollama running locally

Configuration

Create an appsettings.json file in the CLI or Desktop project:

{
  "CodeReview": {
    "Provider": "AzureOpenAI",
    "AzureOpenAI": {
      "Endpoint": "https://your-resource.openai.azure.com/",
      "DeploymentName": "gpt-4o",
      "ApiKey": "your-api-key"
    },
    "OpenAI": {
      "ApiKey": "your-api-key",
      "Model": "gpt-4o"
    },
    "Ollama": {
      "Endpoint": "http://localhost:11434",
      "Model": "llama3"
    },
    "Git": {
      "DefaultBaseBranch": "main"
    }
  }
}

CLI Usage

# Analyze current branch against main
dotnet run --project src/MattEland.CodeReview.Cli -- analyze

# Specify base branch
dotnet run --project src/MattEland.CodeReview.Cli -- analyze --base develop

# Analyze specific files
dotnet run --project src/MattEland.CodeReview.Cli -- analyze --files "src/Service.cs,scripts/migration.sql"

# Output as JSON
dotnet run --project src/MattEland.CodeReview.Cli -- analyze --output json

Desktop App

# Run the Uno Platform desktop app
dotnet run --project src/MattEland.CodeReview.Desktop/MattEland.CodeReview.Desktop

Built-in Rules

SQL Rules (SQL Caffeine Top 10)

Rule	Description
select-star	SELECT * fetches unnecessary columns
non-sargable	Functions on columns prevent index usage
type-mismatch	Implicit type conversions
n-plus-one-where	Correlated subqueries in WHERE
n-plus-one-select	Scalar subqueries in SELECT
unnecessary-distinct	DISTINCT masking join problems
or-conditions	OR preventing index optimization
not-in-null	NOT IN with nullable columns
missing-indexes	Queries on unindexed columns
no-limit	Unbounded result sets

C# Rules

Category	Rule	Description
Security	hardcoded-secrets	API keys, passwords in code
Security	insecure-deserialization	Unsafe JSON/XML deserialization
Performance	blocking-async	.Result, .Wait() calls
Performance	n-plus-one-linq	LINQ queries in loops
Logic	null-after-check	Null dereference issues
Logic	off-by-one	Loop boundary errors

Custom Prompts

Add custom .prompt files to %AppData%/MattEland.CodeReview/prompts/ (Windows) or ~/.config/MattEland.CodeReview/prompts/ (Linux/macOS).

.prompt File Format

---
id: sql/performance/custom-rule
name: Custom Rule Name
description: What this rule detects
severity: warning
tags: [performance, custom]
---
## Role
You are an expert code reviewer...

## Detection Target
Look for patterns that...

## Input
Analyze this diff:
{{diff}}

## Output Format
Return JSON array of issues...

Architecture

See the Architectural Decision Records for design rationale.

License

MIT License - see LICENSE for details.