Diffy

A modern, native diff tool for macOS built with Tauri and TypeScript.

Features

• Side-by-side text comparison
• Syntax highlighting for differences
• Drag & drop file support
• Text manipulation tools (lowercase, sort, trim)
• Diff history with configurable retention
• Keyboard shortcuts for productivity
• Native macOS app with system integration

Installation

Homebrew (Recommended)

Install with a single command:

brew install --cask atlascodesai/diffy/diffy

This automatically taps the repository and installs Diffy. No separate tap command needed!

Alternative: If you prefer to tap first:

brew tap atlascodesai/diffy
brew install --cask diffy

Manual Installation

1. Download the latest release for your architecture:

   • Apple Silicon (M1/M2/M3): diffy-aarch64-apple-darwin.tar.gz
   • Intel: diffy-x86_64-apple-darwin.tar.gz

2. Extract the archive and drag Diffy.app to your Applications folder

3. On first launch, if you see a security warning, go to System Settings → Privacy & Security and click "Open Anyway"

Usage

Launch Diffy from Applications or run from terminal:

open -a Diffy
# or
diffy

Keyboard Shortcuts

• ⌘ + Enter or ⌘ + R - Run comparison
• ⌘ + N - New diff (clear all)
• ⌘ + H - Toggle history sidebar
• ⌃ + ⌥ + S - Switch left and right text
• ⌃ + ⌥ + R - Clear all
• ESC - Close history sidebar

Development

Prerequisites

• Node.js 20+
• Rust (latest stable)
• Xcode Command Line Tools

Setup

npm install

Run Development Server

npm run tauri dev

Build for Production

npm run tauri build

Release Process

Releases are fully automated via GitHub Actions when a version tag is pushed.

Creating a New Release

1. Update version numbers in all config files:

   • src-tauri/Cargo.toml - version = "X.Y.Z"
   • src-tauri/tauri.conf.json - "version": "X.Y.Z"
   • package.json - "version": "X.Y.Z"
   • index.html - version number in settings modal

2. Commit changes:

   git add .
   git commit -m "Bump version to vX.Y.Z"
   git push

3. Create and push tag:

   git tag vX.Y.Z
   git push origin vX.Y.Z

4. Automated workflow will:

   • Build for both Intel (x86_64) and Apple Silicon (aarch64)
   • Sign the app with Developer ID Application certificate
   • Notarize with Apple for Gatekeeper
   • Create GitHub Release with binaries and SHA256 checksums
   • Automatically update Homebrew cask formula

GitHub Secrets Required

The following secrets must be set in the repository:

• APPLE_CERTIFICATE_BASE64 - Base64-encoded .p12 certificate
• APPLE_CERTIFICATE_PASSWORD - Certificate password
• APPLE_ID - Apple Developer email
• APPLE_TEAM_ID - Apple Developer Team ID
• APPLE_APP_PASSWORD - App-specific password for notarization
• HOMEBREW_TAP_TOKEN - GitHub PAT with repo access for homebrew-diffy

Code Signing & Notarization

The app is signed with a Developer ID Application certificate and notarized with Apple to ensure it passes Gatekeeper checks. This happens automatically in CI.

For local signing setup:

1. Export certificate from Keychain as .p12
2. Convert to base64: base64 -i certificate.p12 -o certificate.p12.base64
3. Add to GitHub Secrets

Architecture

• Frontend: Vanilla TypeScript + Vite
• Backend: Rust + Tauri 2.0
• Diff Engine: jsdiff
• Styling: Custom CSS with system fonts
• Build: GitHub Actions with matrix builds for multi-architecture support

Repository Structure

• src/ - TypeScript frontend code
• src-tauri/ - Rust backend code
• .github/workflows/ - CI/CD pipelines
• public/ - Static assets

Distribution

• Primary: Homebrew Cask via homebrew-diffy
• Secondary: Direct downloads from GitHub Releases
• Platforms: macOS only (Intel & Apple Silicon)

License

MIT

Credits

Built with:

• Tauri
• jsdiff
• Vite
• TypeScript