DiffCatcher

git clone https://github.com/Teycir/DiffCatcher.git
cd DiffCatcher
cargo build --release
./target/release/diffcatcher --help

# Scan all repos in a directory (fetch-only, no modifications)
diffcatcher ~/projects

# Pull updates and generate security report
diffcatcher ~/projects --pull -o ./report

# Diff two branches in a single repo (PR review mode)
diffcatcher ./my-repo --diff main..feature/auth -o ./pr-report

# Generate SARIF output for GitHub Code Scanning
diffcatcher ~/projects --summary-format sarif,json -o ./report

# Dry run to see what would be scanned
diffcatcher ~/projects --dry-run

# Fast scan with 8 parallel workers
diffcatcher ~/projects -j 8 --quiet

# Scan with default settings (fetch-only)
diffcatcher <ROOT_DIR>

# Custom output directory
diffcatcher ~/projects -o ./my-report

# Include nested repos and follow symlinks
diffcatcher ~/projects --nested --follow-symlinks

# Skip hidden directories
diffcatcher ~/projects --skip-hidden

# Fetch only (default - no working tree changes)
diffcatcher ~/projects

# Actually pull changes
diffcatcher ~/projects --pull

# Force pull with stash/pop for dirty repos
diffcatcher ~/projects --pull --force-pull

# Use rebase strategy
diffcatcher ~/projects --pull --pull-strategy rebase

# Skip fetch/pull entirely (historical diffs only)
diffcatcher ~/projects --no-pull

# Skip element extraction (raw diffs only)
diffcatcher ~/projects --no-summary-extraction

# Extract elements but skip code snippets
diffcatcher ~/projects --no-snippets

# Adjust snippet context and limits
diffcatcher ~/projects --snippet-context 10 --max-snippet-lines 300

# Limit elements per diff
diffcatcher ~/projects --max-elements 1000

# Skip security tagging
diffcatcher ~/projects --no-security-tags

# Include test files in security analysis
diffcatcher ~/projects --include-test-security

# Use custom security patterns
diffcatcher ~/projects --security-tags-file ./custom-patterns.json

output = "reports-local"
no_pull = true
history_depth = 2
summary_formats = ["json", "txt"]
no_security_tags = false

[plugins]
security_pattern_files = ["plugins/security-extra.json"]
extractor_files = ["plugins/extractors.json"]

{
  "version": 1,
  "extractors": [
    {
      "name": "policy-rule",
      "kind": "Config",
      "regex": "^policy\\s+([A-Za-z_][A-Za-z0-9_]*)"
    }
  ]
}

# Diff two branches in a single repo
diffcatcher ./my-repo --diff main..feature/auth

# Diff specific commits
diffcatcher ./my-repo --diff abc123..def456

# Diff with SARIF output for CI integration
diffcatcher ./my-repo --diff origin/main..HEAD --summary-format sarif -o ./pr-report

# Generate SARIF alongside other formats
diffcatcher ~/projects --summary-format sarif,json,md

# SARIF-only for CI/CD upload
diffcatcher ~/projects --summary-format sarif -o ./report

# Incremental mode (skip unchanged repos)
diffcatcher ~/projects --incremental -o ./report

# Filter by branch pattern
diffcatcher ~/projects --branch-filter "main"

# Adjust history depth
diffcatcher ~/projects --history-depth 5

# JSON output for CI/CD
diffcatcher ~/projects --quiet --json > result.json

# Verbose output with discovered paths
diffcatcher ~/projects --verbose

<report_dir>/
├── summary.json                    # Global summary
├── summary.md                      # Markdown summary
├── results.sarif                   # SARIF 2.1.0 output (when --summary-format sarif)
├── security_overview.json          # Cross-repo security aggregation
├── security_overview.md
├── <repo-name>/
│   ├── status.json                 # Repo state
│   ├── pull_log.txt
│   └── diffs/
│       ├── diff_N_vs_N-1.patch     # Raw unified diff
│       ├── changes_N_vs_N-1.txt    # File manifest
│       ├── summary_N_vs_N-1.json   # Element extraction
│       ├── summary_N_vs_N-1.md
│       └── snippets/
│           ├── 001_validate_token_ADDED.rs
│           ├── 002_check_permissions_BEFORE.rs
│           ├── 002_check_permissions_AFTER.rs
│           └── 002_check_permissions.diff
└── ...

{
  "version": 1,
  "mode": "extend",
  "tags": [
    {
      "tag": "pii-handling",
      "description": "PII data processing",
      "severity": "High",
      "patterns": ["ssn", "social_security", "passport"]
    }
  ]
}

src/
├── cli.rs              # Argument parsing
├── scanner.rs          # Repository discovery
├── git/                # Git operations
│   ├── commands.rs     # Git wrappers
│   ├── state.rs        # State capture
│   ├── diff.rs         # Diff generation
│   └── file_retrieval.rs
├── extraction/         # Element extraction
│   ├── parser.rs       # Unified diff parser
│   ├── elements.rs     # Element detection
│   ├── snippets.rs     # Code snippet extraction
│   ├── boundary.rs     # Bracket/indentation tracking
│   └── languages/      # Language-specific patterns
├── security/           # Security tagging
│   ├── tagger.rs       # Pattern matching
│   ├── patterns.rs     # Built-in patterns
│   └── overview.rs     # Cross-repo aggregation
└── report/             # Report generation
    ├── writer.rs       # Directory structure
    ├── json.rs         # JSON serialization
    ├── sarif.rs        # SARIF 2.1.0 output
    ├── markdown.rs     # Markdown formatting
    └── snippet_writer.rs

ls | while read line; do git -C "$line" diff HEAD~1 HEAD || true; done

# Run all tests
cargo test

# Run specific test suite
cargo test security_tagger

# Run with output
cargo test -- --nocapture

# Compile benchmark binaries
cargo bench --no-run

# Run benchmark harness
cargo bench --bench core_bench

cargo doc --open