Committing changes

Before committing changes, run grunt (which runs tests and linting):


If grunt doesn’t succeed, the continuous integration tests will fail as well.

Modifying .ad.js files

Files with names which end with .ad.js are transformed to use AD primitives when WebPPL is installed.

During development it is necessary to run this transform after any such files have been modified. A grunt task is provided that will monitor the file system and run the transform when any .ad.js files are updated. Start the task with:

grunt build-watch

Alternatively, the transform can be run directly with:

grunt build

The scope of the transform is controlled with the 'use ad' directive. If this directive appears directly after the 'use strict' directive at the top of a file, then the whole file will be transformed. Otherwise, those functions which include the directive before any other statements or expressions in their body will be transformed. Any function nested within a function which includes the directive will also be transformed.


To only run the tests, do:

npm test

To reproduce intermittent test failures run the inference tests with the random seed displayed in the test output. For example:

RANDOM_SEED=2344512342 nodeunit tests/test-inference.js

nodeunit can also run individual tests or test groups. For example:

nodeunit tests/test-inference.js -t Enumerate

See the nodeunit documentation for details.


To only run the linter:

grunt lint

For more semantic linting, try:

grunt hint

If the linter complains about style errors (like indentation), you can fix many of them automatically using:

grunt lint --fix --force

Browser version

To generate a version of WebPPL for in-browser use, run:

npm install -g browserify uglify-js
grunt bundle

The output is written to bundle/webppl.js and a minified version is written to bundle/webppl.min.js.

To use in web pages:

<script src="webppl.js"></script>

We also provide an in-browser editor for WebPPL code.


To check that compilation was successful, run the browser tests using:

grunt test-browser

The tests will run in the default browser. Specify a different browser using the BROWSER environment variable. For example:

BROWSER="Google Chrome" grunt test-browser

Incremental compilation

Repeatedly making changes to the code and then testing the changes in the browser can be a slow process. watchify speeds up this process by performing an incremental compile whenever it detects changes to source files. To start watchify use:

npm install -g watchify
grunt browserify-watch

Note that this task only updates bundle/webppl.js. Before running the browser tests and deploying, create the minified version like so:

grunt uglify


Packages can also be used in the browser. For example, to include the webppl-viz package use:

grunt bundle:path/to/webppl-viz

Multiple packages can specified, separated by colons.