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A Nose plugin for integrating JavaScript tests into a Python test suite.

Project description

NoseJS is a Nose plugin for integrating JavaScript tests into a Python test suite.


NoseJS is designed for Python projects that require JavaScript code for some Web functionality. It currently has two features:

  • Discover and run JavaScript tests alongside Python tests

  • Validate JavaScript syntax (check for lint).


There are some optional external dependencies in the sections below.

You can get NoseJS with easy_install

$ easy_install NoseJS

Or you can clone the source using Mercurial from and install it with

$ python develop

Checking JavaScript Syntax

NoseJS will find JavaScript files (e.g. app.js) along the Nose path and run them through the jsl command line tool to check for “lint.” In other words, show you syntax errors, warnings, etc. You can install jsl on most systems using your package manager (i.e. port install javascript-lint on Mac OS X) otherwise it is available for download on the jsl site.


To check for lint without running any JavaScript unit tests, type:

$ nosetests --with-javascript --no-javascript-tests path/to/javascript

To disable lint checking, add --no-javascript-lint

Running JavaScript Tests

NoseJS will also find and run JavaScript test files, those that match Nose’s test pattern and end in .js. Currently, NoseJS supports running executing tests in Rhino, a Java implementation of the JavaScript language. There is experimental support for python-spidermonkey using the --spidermonkey switch.


Assuming you’ve downloaded Rhino into ~/src, discover and run JavaScript tests with this command:

$ nosetests --with-javascript --rhino-jar ~/src/rhino1_7R1/js.jar path/to/javascript/tests

This command would look for any files along Nose’s path ending in .js that match Nose’s current test pattern, collect them all, then execute them using Rhino in a single Java subprocess at the end of all other tests. By default, files looking like test*.js will be collected and run.

The idea behind NoseJS is that you might have a Python web application that relies on JavaScript for some of its functionality and you want to run both Python and JavaScript tests with one command, nosetests. You can put these JavaScript tests wherever you want in your project.

Here is a more realistic example that shows how the Fudge project is tested simultaneously for Python and JavaScript functionality. Its project layout looks roughly like this:

|-- fudge
|   |--
|   |--
|   |-- tests
|   |   |--
|   |   |--
|   |   |--
|-- javascript
|   |-- fudge
|   |   |-- fudge.js
|   |   |-- tests
|   |   |   |-- test_fudge.html
|   |   |   `-- test_fudge.js

Both Python and JavaScript tests can be run with this command:

$ nosetests  --with-javascript \
             --rhino-jar ~/src/rhino1_7R1/js.jar \
             --with-dom \
             --javascript-dir javascript/fudge/tests/
Test Fake
  can find objects
  can create objects
  expected call not called
  call intercepted
  returns value
  returns fake
Test ExpectedCall
  ExpectedCall properties
  call is logged
Test fudge.registry
  expected call not called
  start resets calls
  stop resets calls
  global stop
  global clear expectations

Loaded 6 JavaScript files

Ran 54 tests in 0.392s


The dots are the Python tests that were run and the output below that is what Fudge’s JavaScript test files printed out. Be sure to read the Caveats section below ;)

Specifying a path to JavaScript files

If JavaScript files are nested in a subdirectory, like the above example, specify that directory with:

$ nosetests --with-javascript --javascript-dir javascript/fudge/tests/ --javascript-dir ./another/dir

nosejs JavaScript namespace

All JavaScripts have the nosejs JavaScript namespace available for use. The following methods are available:

  • nosejs.requireFile(path)

    • Load a JavaScript file from your test script. If you require the same file multiple times, it will only be loaded once. If the file does not start with a slash, then it should be a path relative to the directory of the script where requireFile() was called from. For example, here is how test_fudge.js requires the fudge library before testing:

      if (typeof nosejs !== 'undefined') {
  • nosejs.requireResource(name)

    • Require a JavaScript file that is bundled with NoseJS. There are a few available resources:


      Will load the JQuery library before loading any other tests


      Will load a very minimal set of JavaScript functions for testing. It is a partial implementation of the QUnit test runner interface. Supported methods: module(), test(), equals(), ok(), and expect()

      For example, test_fudge.js uses jquery and the testrunner

      if (typeof nosejs !== 'undefined') {

Using the DOM

If your JavaScript under test relies on a browser-like DOM environment, it might still work! Just run:

$ nosetests --with-javascript --with-dom

This will load a copy of John Resig’s env.js script to simulate a DOM before loading any other JavaScript. There are a few very minor patches made to env.js, marked with @@nosejs in the NoseJS source.


  • Currently if JavaScript tests fail, nosetests will not indicate failure and its exit status will be unaffected. I can’t figure out a clean way to do this. Please get in touch if you’d like to help.

  • In general, JavaScript tests are not very well integrated into Nose.

Wait … Python and Java?

Rhino is pretty much the only stable, command line oriented implementation of JavaScript I know of and it’s well supported by Mozilla.

Alternatively, John J. Lee created a Python binding to the fast Spider Monkey engine, Atul Varma revived it once in a fork on Google Code, and now Paul J. Davis is working on it (in git and it is released on PyPI).

There is current experimental support for Python Spidermonkey in NoseJS using the --spidermonkey option, which switches out the JavaScript engine.


Please submit bugs and patches. All contributors will be acknowledged. Thanks!


  • 0.9.4

    • Multiple paths for the –javascript-dir option can now be specified on multiple lines in setup.cfg

  • 0.9.3

    • Added –with-javascript-only option to stop execution of any other Nose tests when needed.

  • 0.9.2

    • CHANGED: The –js-test-dir option is now known as –javascript-dir

    • Added experimental support for python-spidermonkey

    • Added JavaScript lint check using the jsl tool

    • Fixed bugs in how custom paths to JavaScript were expanded

  • 0.9.1

    • Fixed distribution problem

  • 0.9

    • Initial release

To Do

  • Better spidermonkey support

  • Distribute a Rhino js.jar with NoseJS

  • Upgrade env.js using git repo

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