wraps up your node modules into web modules
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  • WrapUp compiles CommonJS 1.0 modules for the browser.
  • WrapUp does not try to have a working require implementation for the browser, infact the loader WrapUp uses is incredibly simple.
  • WrapUp ignores duplicates that may be present when using npm to install packages.
  • WrapUp supports building multiple versions of the same package.
  • WrapUp supports circular module dependencies.
  • WrapUp can watch source files for changes and rebuild automatically.
  • WrapUp can convert CommonJS modules to AMD modules.

Build Status


WrapUp is installed via npm:

npm install wrapup -g

After that, you will have access to wrup in your cli.

wrup --help

You can also install locally:

npm install wrapup

And require WrapUp in your node javascripts:

var wrup = require("wrapup")()


In a nutshell, you tell WrapUp you require something, it calculates dependencies for something using static analysis, and compiles a single JavaScript file that only exposes that something you required. require paths inside modules are replaced with unique identifiers for brevity, and you will only be able to access directly that something you required, never dependencies (unless specifically required).


The main WrapUp method is require(namespace, module).

It resolves a module using node's own modules and packages logic, so for instance, wrup.require("colors") would look in your node_modules folder for a package named colors, then proceed to load its main. The namespace parameter is optional, but it's used to expose the module to the browser. Without a namespace, the module will be required without being assigned. A bit like doing var x = require(y) vs require(y).


wrup --require colors colors --require someName ./path/to/otherModule --require someOtherPackage


var wrup = require("wrapup")() // require + instantiate

wrup.require("colors", "colors")
    .require("someName", "./path/to/otherModule")
    .up(function(err, js){

the above would let you access colors and someName, while having someOtherPackage simply required without being assigned to any variable. The ouput code assigning variables would look like this:

// those are global var statements
var colors = require("colors")
var someName = require("someName")


WrapUp supports watching source files and rebuilds automatically whenever one of these changes.




Instead of using the .up() method, the .watch() method is used.

var wrup = require("wrapup")() // require + instantiate
wrup.require("y", "./moduley.js").watch()

wrup.on("data", function(js){
    fs.writeFile("path/to/wherever", js)

wrup.on("change", function(file){
    console.log(file + " changed.")

In the above example, whenever module y and any module required by module y changes, .up() is called again. The data event is fired whenever WrapUp builds, either be a direct .up() call or an .up() call triggered by a changed file. The change event is fired whenever watch is set to true and one of the source files changes.


Set some options for the output.

    globalize: "MyNamespace"
  • globalize define the global scope where named modules are attached to. By default it uses global var statements.
  • compress if set to true, will compress the resulting javascript file using uglify-js. Defaults to false.
  • output only available in the cli, used to specify an output file. defaults to stdout.
  • sourcemap (cli: --source-map) Specify an output file where to generate source map.
  • sourcemapURL (cli: --source-map-url) //@ sourceMappingURL value, URL to the saved sourcemap file.
  • sourcemapRoot (cli: --source-map-root) The path to the original source to be included in the source map.
  • ast the output is a JSON object of the AST, instead of JavaScript. Can be used as uglifyjs input, using uglifyjs --spidermonkey.


Additional cli options:

  • --amd when using the --amd, it will convert CommonJS modules to AMD modules. The --output option should be a directory.
  • --digraph generate a dot output. If you've installed graphviz, you can use the --output option, like --output graph.png


        globalize: "MyNameSpace",
        compress: true,
        sourcemap: "./somefile.map"
    }).on("data", function(js){
        fs.writeFile("./somefile.js", js)

Using Source Maps

The options for source-maps that can be used are --source-map and --source-map-root.

Once the .map file is created, the page with the JavaScript can be opened. It is important that the original files are accessible through http too. For example when using --require ./test/a --source-map test.map --source-map-root http://foo.com/src the file http://foo.com/src/test/a.js should be the original JavaScript module.

Using with Uglify-JS

The WrapUp output can be piped into UglifyJS if more compression options are desired. For example using the --define option to set global definitions.

wrup -r ./main.js --source-map ./main.map \
     | uglify -d DEV=false --compress --mangle --output ./main.min.js \
              --source-map main.map --in-source-map main.map

Using the --ast option, and the UglifyJS --spidermonkey option, the code can be piped to UglifyJS as an Abstract Syntax Tree JSON. This saves UglifyJS parsing the generated WrapUp JavaScript.

wrup -r ./main --ast | uglifyjs --spidermonkey -c -m --output compressed.js

Stream and pipe

WrapUp implements Node Stream which means it is possible to pipe the WrapUp output to other writable streams, like fs.WriteStream, process.stdout or http.ServerResponse.

http.createServer(function(req, res){
    var wrup = wrapup()



# simple building a file
wrup --require ./main.js --output built.js

# compressing the file
wrup --require ./main.js --output built.js --compress

# watching, and use another global object, so MyNameSpace.modulename == module.exports of main.js
wrup --require modulename ./main.js --globalize MyNameSpace --compress --output path/to/file.js --watch

# export modules in the global scope with "var" statements
# this will create a "var moofx = ..." statement
wrup -r moofx ./moofx

# building AMD
wrup --require ./main.js --amd --output ./converted-to-amd

# piping the AST JSON into uglifyjs
wrup --require ./main.js --ast | uglifyjs --spidermonkey -c -m

# source maps
wrup -r ./main.js --output test.js --source-map test.map

# generating a visual dependency graph
wrup -r ./main --digraph
# this requires that graphviz is installed
wrup -r ./main --digraph --output graph.png
# or pipe it into the "dot" command line tool
wrup -r ./main --digraph | dot -Tpng -o graph.png


coming soon... :)