Webpack 'use-strict' loader

use-strict-loader.js

var OriginalSource = require('webpack/lib/OriginalSource');

module.exports = function(source, map){
    var identifier = this._module.identifier();

    this.cacheable();

    var origMap = this.sourceMap ? new OriginalSource(source, identifier, map) : null;

    var strictPrefix = '"use strict";\n';
    source = strictPrefix + source;
    if (origMap) origMap.node().prepend(strictPrefix);

    return this.callback(null, source, origMap ? origMap.map() : null);
};

Lovely!
why is this not on npm yet? ;)

@danielberndt @loganfsmyth it's on npm now: https://www.npmjs.com/package/strict-loader