DiffDeck

DiffDeck is a powerful, flexible code difference analysis tool that helps developers understand, document, and secure their code changes. It provides rich diff visualization, security scanning, and various output formats to suit different needs.

Features

• 🔍 Smart Diff Analysis: Compare branches, commits, or local files with intelligent diff algorithms
• 🛡️ Security Scanning: Built-in security checks for sensitive data and potential vulnerabilities
• 📊 Multiple Output Formats: Support for plain text, Markdown, MDX, and XML outputs
• 🎨 Customizable Styling: Line numbers, custom headers, and formatting options
• 🚀 Performance Optimized: Efficient processing of large codebases
• 🔒 Security First: Automatic scanning for sensitive data and security issues
• 📋 Clipboard Integration: Direct copying of diff output to clipboard

Installation

go install github.com/KnockOutEZ/diffdeck/cmd/diffdeck@latest

Or build from source:

git clone https://github.com/KnockOutEZ/diffdeck.git
cd diffdeck
go build ./cmd/diffdeck

Quick Start

1. Compare two branches:

diffdeck --from-branch develop --to-branch main

2. Compare with custom output:

diffdeck --from-branch develop --to-branch main --output diff.md --style markdown

3. Enable security scanning:

diffdeck --from-branch develop --to-branch main --security-check

Configuration

DiffDeck can be configured via JSON configuration file. Default location is diffdeck.config.json.

Basic Configuration Example:

{
  "output": {
    "filePath": "diffdeck-output.txt",
    "style": "mdx",
    "showLineNumbers": true,
    "copyToClipboard": true,
    "topFilesLength": 5
  },
  "include": ["**/*"],
  "ignore": {
    "patterns": [
      ".git/**",
      "node_modules/**",
      "vendor/**"
    ]
  },
  "security": {
    "disableSecurityCheck": false,
    "maxFileSize": 10485760
  }
}

Configuration Options Explained

Output Configuration

"output": {
  "filePath": "diffdeck-output.txt",  // Output file path
  "style": "mdx",                     // Output format: plain, markdown, mdx, xml
  "showLineNumbers": true,            // Include line numbers in diff
  "copyToClipboard": true,           // Copy output to clipboard
  "topFilesLength": 5                // Number of files in summary
}

File Patterns

"include": ["**/*"],              // Files to include
"ignore": {
  "patterns": [                   // Files to ignore
    ".git/**",
    "node_modules/**",
    "vendor/**"
  ]
}

Security Settings

"security": {
  "disableSecurityCheck": false,  // Enable/disable security scanning
  "maxFileSize": 10485760        // Max file size to scan (10MB)
}

Git Settings

"git": {
  "defaultRemote": "",           // Default remote repository
  "cacheDir": "/tmp/cache",      // Cache directory location
  "timeout": "5m"               // Git operation timeout
}

Command Line Usage

Basic Commands

# Compare branches
diffdeck --from-branch feature --to-branch main

# Use specific config file
diffdeck --config my-config.json --from-branch feature --to-branch main

# Generate markdown output
diffdeck --style markdown --output diff.md --from-branch feature --to-branch main

# Disable security checks
diffdeck --no-security-check --from-branch feature --to-branch main

# Show line numbers
diffdeck --show-line-numbers --from-branch feature --to-branch main

Advanced Usage

# Custom include/ignore patterns
diffdeck --include "src/**/*.js" --ignore "**/*.test.js"

# Set custom file size limit
diffdeck --max-file-size 20971520

# Compare specific files
diffdeck --files "src/main.js,src/utils.js"

# Use custom cache directory
diffdeck --cache-dir "/custom/cache/path"

Output Formats

Plain Text

diffdeck --style plain

Generates simple text output with basic formatting.

Markdown

diffdeck --style markdown

Generates GitHub-flavored Markdown with syntax highlighting.

MDX

diffdeck --style mdx

Generates MDX format suitable for React documentation.

XML

diffdeck --style xml

Generates structured XML output for programmatic processing.

Security Scanning

DiffDeck includes built-in security scanning capabilities:

• Sensitive data detection (API keys, tokens)
• Password pattern matching
• Private key detection
• Internal URL/IP detection
• AWS credentials scanning

Enable/disable security scanning:

# Enable
diffdeck --security-check

# Disable
diffdeck --no-security-check

File Pattern Syntax

DiffDeck uses glob patterns for file matching:

• **/* - Match all files
• *.{js,ts} - Match JavaScript and TypeScript files
• src/**/*.go - Match Go files in src directory
• !test/** - Exclude test directory

Performance Tips

1. Use appropriate maxFileSize limit
2. Leverage ignore patterns for large directories
3. Use cache directory for repeated operations
4. Consider disabling security checks for large diffs
5. Use specific include patterns when possible

Integration Examples

GitHub Actions

- name: Run DiffDeck
  run: |
    diffdeck --from-branch ${{ github.event.pull_request.base.ref }} \
             --to-branch ${{ github.event.pull_request.head.ref }} \
             --output diff.md \
             --style markdown

GitLab CI

diff_check:
  script:
    - diffdeck --from-branch $CI_MERGE_REQUEST_TARGET_BRANCH_NAME \
               --to-branch $CI_MERGE_REQUEST_SOURCE_BRANCH_NAME \
               --style markdown \
               --output diff.md

Common Issues and Solutions

1. Large Files

   • Increase maxFileSize in config
   • Use more specific include patterns

2. Performance Issues

   • Optimize ignore patterns
   • Use cache directory
   • Consider disabling security checks

3. Git Integration

   • Ensure correct branch names
   • Check timeout settings
   • Verify git credentials

Contributing

1. Fork the repository
2. Create your feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request

License

MIT License - see LICENSE file for details.