The YUI Easy Testing Interface: run browser JS unit tests from the command line!
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Yeti Next

Build Status

Yeti is a command-line tool for launching JavaScript unit tests in a browser and reporting the results without leaving your terminal. Yeti is designed to work with tests built on YUI Test just as they are.

Using Yeti

Running a test

Just run Yeti with the HTML file containing your test.

$ yeti test/fixture/basic.html
Creating a Hub at http://localhost:9000
Waiting for agents to connect at http://localhost:9000.
When ready, press Enter to begin testing.

Point your browsers at that URL, then come back and press Enter.

  Agent connected: Safari (5.1.2) / Mac OS [Hit Enter]

✔ Testing started!
✔ Yeti Simple Test Suite on Safari (5.1.2) / Mac OS
✔ Agent completed: Safari (5.1.2) / Mac OS
1 test passed! (175ms)

Yeti exits automatically when all tests complete. If test failures occur, Yeti will exit with a non-zero status code.

Yeti Hub

To save time, start a Yeti Hub.

$ yeti --server
Yeti Hub listening on port 9000.

Point browsers at your local Yeti on port 9000. Now, you're ready to run tests without having to reconnect browsers each time.

In another Terminal, running Yeti will connect to this Hub instead of starting a new one.

$ yeti test/fixture/basic.html
Connected to http://localhost:9000
Waiting for agents to connect at http://localhost:9000.
When ready, press Enter to begin testing. [Hit Enter]
✔ Testing started!
✔ Yeti Simple Test Suite on Safari (5.1.2) / Mac OS
✔ Agent completed: Safari (5.1.2) / Mac OS
1 test passed! (107ms)

Sharing Your Yeti Hub

Your Yeti Hub can be shared with other developers.

First, I'll start a Hub on on port 80.

$ yeti --server --port 80

Go ahead and point a few browsers there.

Now, others can connect to it from their computer like so:

$ yeti --hub test/fixture/basic.html
Connected to
Waiting for agents to connect at
When ready, press Enter to begin testing.

Your pwd and your test file will be served through the Hub. Like magic.

[Hit Enter]
✔ Testing started!
✔ Yeti Simple Test Suite on Safari (5.1.2) / Mac OS
✔ Agent completed: Safari (5.1.2) / Mac OS
1 test passed! (189ms)

This makes it really simple to setup an ad-hoc testing lab shared with your team.

Caveat: Yeti Next has not been tested with a large number of browsers and Hub clients. If you'd like to help change this, see the Contribute section below.

Error handling

Yeti will report an uncaught exceptions as Script Errors.

Yeti enforces No-Quirks Mode in your tests because it may impact DOM-related APIs. Add a DOCTYPE to your test document to fix this.

Mobile testing made easy

When combined with localtunnel, mobile testing is simple. If you're not dealing with sensitive information, startup your Yeti Hub and then run:

$ localtunnel 9000
   Port 9000 is now publicly accessible from ...

You can then visit that URL on your mobile (or any other) device and have it run new tests.

Yeti API

You can require("yeti") inside your application to script Yeti for your own use.

For API documentation:

  • Run make html to build HTML documentation to ./build_docs.
  • Review code comments inside lib/yeti.js, lib/client.js and lib/hub/index.js.

Yeti follows Semantic Versioning but is currently at a 0.x.y release. The public API is not stable. There will be changes.


Yeti is known to work on Mac OS X and Linux.

You must start Yeti's client in the directory you'll be serving tests from. For security reasons, Yeti will reject requests that try to access files outside of the directory you start Yeti in.


Yeti requires Node.js v0.6.x.

Latest snapshot

# Install Yeti from the latest source from GitHub's yui/yeti repo.
npm install -g

Latest release

If you have problems with the latest Yeti, you may install the last stable release instead:

npm install -g yeti


Installing localtunnel helps proxy Yeti outside of your firewall. It's available as a Ruby gem:

gem install localtunnel

Develop Yeti

Do you want to add new features or fix bugs in Yeti itself? We made it easy for you to hack on Yeti.

Install dependencies

Clone Yeti.

git clone
cd yeti

Install Yeti's devDependencies.

npm install

Yeti's automated tests use PhantomJS. Install it.

# For Mac OS X and Homebrew:
brew update
brew install phantomjs

Run tests

Requires PhantomJS to be installed.

make test

Code coverage

Requires PhantomJS to be installed.

make coverage

This command uses JSCoverage for Node.js, which will be built and installed to ./tools/jscoverage.

HTML documentation


Documentation will be built to build_docs/.

make html

Yeti uses Selleck to generate its website. Selleck files are located in doc/.

JavaScript API

Documentation will be built to build_docs/api/everything/.

make html-api

Yeti uses YUIDocJS to generate API documentation from inline JSDoc comment blocks.


make lint

You may also run the linter on individual files with ./lint:

./lint test/blizzard.js

Yeti uses JSHint to analyze code for problems. See .jshintrc for options used by Yeti.

Contribute to Yeti

Your contributions are welcome! Please review the YUI contributor guide before contributing.

If you haven't contributed to a YUI project before, you'll need to review and sign the YUI CLA before we can accept your pull request.

Contribution Checklist

  1. Run make lint and make sure your new code runs through the linter without error.
  2. Run make coverage and make sure your new code is covered with a test. Tests are located in test and use Vows.

Bugs & Feedback

Open a ticket on's Yeti Issue Tracker to report bugs or feature requests.

Yeti is an experimental project of YUI Labs. As such, it doesn't receive the same level of support as other mature YUI projects.


Yeti is free to use under YUI's BSD license. See the LICENSE file or the YUI license page for license text and copyright information.