diedeadcode 0.1.0

# diedeadcode

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[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
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**Conservative dead code detection for TypeScript and JavaScript.**

`ddd` finds unused exports, unreachable functions, and dead code in your codebase with confidence scoring to minimize false positives.

## Features

- **Fast** - Built on [oxc](https://oxc.rs) for blazing-fast parsing
- **Conservative** - Confidence scoring reduces false positives
- **Transitive analysis** - Detects code that's only called by other dead code
- **Framework-aware** - Understands Next.js, Express, Jest, Vitest patterns
- **Configurable** - Ignore patterns, entry points, and more

## Installation

### npm (recommended)

```bash
npm install -D @dean0x/diedeadcode
```

Or run directly with npx:

```bash
npx @dean0x/diedeadcode .
```

### Cargo

```bash
cargo install diedeadcode
```

### Homebrew (macOS)

```bash
brew install dean0x/tap/diedeadcode
```

### Build from source

```bash
git clone https://github.com/dean0x/diedeadcode.git
cd diedeadcode
cargo build --release
```

## Quick Start

```bash
# Analyze current directory
ddd .

# Analyze with verbose output
ddd . --verbose

# Initialize config file
ddd init

# Output as JSON
ddd analyze . --format json

# Check mode (exit code 1 if dead code found, useful for CI)
ddd analyze . --check
```

## Configuration

Run `ddd init` to generate a `ddd.toml` in your project root, or create one manually:

```toml
# Files to analyze
include = ["**/*.ts", "**/*.tsx", "**/*.js", "**/*.jsx"]
exclude = ["**/node_modules/**", "**/dist/**", "**/*.test.*"]

# Entry points
[entry]
files = ["src/index.ts", "src/main.ts"]
patterns = ["**/pages/**/*.tsx"]  # e.g., Next.js pages
autoDetect = true  # Detect from package.json

# Output settings
[output]
format = "table"  # table, json, or compact
minConfidence = "high"  # high, medium, or low
showChains = true

# Analysis settings
[analysis]
ignoreSymbols = ["logger", "debug"]
ignorePatterns = ["^_"]  # Ignore symbols starting with _
```

## How It Works

1. **Parse** - Uses oxc to build an AST for each file
2. **Extract** - Identifies all exports, functions, classes, and variables
3. **Graph** - Builds a call graph tracking all references
4. **Propagate** - BFS from entry points to find unreachable code
5. **Score** - Assigns confidence based on patterns and heuristics

### Confidence Scoring

Not all dead code warnings are equal. `ddd` scores each finding:

| Score | Meaning |
|-------|---------|
| 90-100 | High confidence - likely dead |
| 70-89 | Medium confidence - review recommended |
| <70 | Lower confidence - may be false positive |

Factors that reduce confidence:
- Dynamic imports (`import()`)
- Reflection (`eval`, `Reflect.*`)
- Decorated symbols (decorators often indicate framework usage)
- String property access patterns
- Exported symbols (may be used externally)

## Output Formats

```bash
# Table (default)
ddd .

# JSON for tooling integration
ddd analyze . --format json

# Compact single-line per issue
ddd analyze . --format compact
```

## Exit Codes

| Code | Meaning |
|------|---------|
| 0 | No dead code found |
| 1 | Dead code found |
| 2 | Error during analysis |

## Performance

`ddd` is designed for large codebases:

- Parallel file parsing with rayon
- Memory-efficient AST traversal

## Contributing

See [CONTRIBUTING.md](CONTRIBUTING.md) for guidelines.

## License

MIT - see [LICENSE](LICENSE)