var swfPath = require("path/to/AS3/source.as");

module: {
        loaders: [
            {
                test: /\.as$/,
                loader: 'flex',
                query: {
                    lib: 'src/flash/libs',
                    src: 'src/flash/src',
                    build: 'src/flash/build/swf',
                    name: '/swf/[name].swf'
                }
            }
        ]
    }

var swfPath = require("flex?name=[name].swf&lib=lib/path&src=src/path&build=build/path!./path/to/AS3/source.as");