Static builder & bundler for Dart projects. Inspired by Webpack.

Warden is a lightweight CLI tool to watch and compile Dart and Sass files for frontend projects that don’t use Flutter, are focused on building to JavaScript for server-side rendered apps, and work with Node-installed packages. It’s ideal for projects that still want custom JS/CSS assets compiled automatically.

📚 Docs: pub.dev/packages/warden

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✨ Features

• 🔁 Watches your Dart and Sass files and recompiles on change
• 📦 Moves specified dependencies (e.g. node_modules assets) into your build output
• 🗂️ Moves specified asset directories (e.g. assets/img/) into your build output
• 🛠️ Bundles your dependency JS files into a single bundle.js (optional)
• 🧱 Fully configurable via a warden.yaml file
• 🎯 Supports multiple tasks like compiling Dart to JS and Sass to CSS
• 🧪 Debug mode logging to see every file operation and build step
• 🚀 Production mode for optimised builds with minified output

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📦 Installation

dart pub global activate warden

Then run:

warden --file=warden.yaml

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▶️ Running

Run Warden in watch mode:

warden --watch
# Or define the file path is not in the project root.
warden --file=warden.yaml --watch

Or for a one-off build:

warden --build
# Or define the file path is not in the project root.
warden --file=warden.yaml --build

Debug mode (development) will show verbose file change and build logs.
Switch to production to build optimised/minified JS and CSS.

dart run warden --file=warden.yaml --watch --debug

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⚙️ Setup

Create a warden.yaml in your project root:

# ==============================
# Warden Configuration
# ==============================

# The root directory of your source files
source_dir: example

# The environment mode to run in (choose 'development' or 'production')
# 🧪 development → Local dev settings, debug logging enabled
# 🚀 production  → Live site settings, minified builds
mode: development # Default is development

# Where to output built files (JavaScript, CSS, etc.)
destination: example/static/

# Main Dart-built JS file (output location)
main_file: example/static/main.js

# ==============================
# Dependencies
# ==============================
dependencies:
  - source: example/node_modules
    bundle: true
    files:
      - "poppyjs/dist/Poppy.min.js"
      - "bootstrap/dist/js/bootstrap.min.js"
      - "bootstrap/scss/bootstrap.scss"

# ==============================
# Static Assets
# ==============================
assets:
  source: example/assets
  directories:
    - img  # Copies `example/assets/img` → `example/static/img`
  compress:
    quality: 70  # File compression for your shipped file assets

# ==============================
# Build Tasks
# ==============================
tasks:
  frontend:
    executable: dart
    args: ["compile", "js", "bin/main.dart", "-O4", "-o", "static/main.js"]
    src: example

  styles:
    executable: dart
    args: ["run", "sass", "sass/index.scss:static/index.css"]
    src: example
    warnings: false

# ==============================
# Environment Variables
# These are injected at compile time for Dart
# ==============================
environment:
  dev:
    API_URL: "http://localhost:1234/api/v1"
    CAT_TYPE: "siberian"
    DEBUG_MODE: "true"
  prod:
    API_URL: "https://www.google.com"
    DEBUG_MODE: "false"

---

🧪 Example Project Structure

examples/
├── bin/
│   └── main.dart
├── lib/
│   └── examples.dart
├── sass/
│   └── index.scss
├── node_modules/
├── warden.yaml

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Contributions
Please open an issue or reply to an existing issue requesting that you would like to work on it. PRs that do not fix a known bug or add new features will be closed.

License
MIT © 2025 joegasewicz