brunch-config.js

exports.config = {
  // See http://brunch.io/#documentation for docs.
  files: {
    javascripts: {
      joinTo: "js/app.js"

      // To use a separate vendor.js bundle, specify two files path
      // http://brunch.io/docs/config#-files-
      // joinTo: {
      //  "js/app.js": /^(web\/static\/js)|(node_modules)/,
      //  "js/vendor.js": /^(web\/static\/vendor)/
      // }
      //
      // To change the order of concatenation of files, explicitly mention here
      // order: {
      //   before: [
      //     "web/static/vendor/js/jquery-2.1.1.js",
      //     "web/static/vendor/js/bootstrap.min.js"
      //   ]
      // }
    },
    stylesheets: {
      joinTo: "css/app.css",
      order: {
        after: ["web/static/css/app.css"] // concat app.css last
      }
    },
    templates: {
      joinTo: "js/app.js"
    }
  },

  conventions: {
    // This option sets where we should place non-css and non-js assets in.
    // By default, we set this to "/web/static/assets". Files in this directory
    // will be copied to `paths.public`, which is "priv/static" by default.
    assets: /^(web\/static\/assets)/
  },

  // Phoenix paths configuration
  paths: {
    // Dependencies and current project directories to watch
    watched: [
      "web/static",
      "test/static"
    ],

    // Where to compile files to
    public: "priv/static"
  },

  // Configure your plugins
  plugins: {
    babel: {
      // Do not use ES6 compiler in vendor code
      ignore: [/web\/static\/vendor/]
    }
  },

  modules: {
    autoRequire: {
      "js/app.js": ["web/static/js/app"]
    }
  },

  npm: {
    enabled: true
  }
};

package.json

{
  "repository": {},
  "license": "MIT",
  "scripts": {
    "deploy": "brunch build --production",
    "watch": "brunch watch --stdin"
  },
  "dependencies": {
    "phoenix": "file:../..",
    "phoenix_html": "file:deps/phoenix_html"
  },
  "devDependencies": {
    "babel-brunch": "6.0.6",
    "brunch": "2.9.1",
    "clean-css-brunch": "2.0.0",
    "css-brunch": "2.6.1",
    "javascript-brunch": "2.0.0",
    "uglify-js-brunch": "2.0.1"
  }
}