jupyter_puppeteer_helpers

Some helpful code for controlling Jupyter from puppeteer using a headless browser.

Although the code does not depend on jest and jest-puppeteer this repository was primarily built to provide common tools for creating end-to-end tests for Jupyter widget implementations using jest with puppeteer as a testing engine.

The module may also be helpful for automatically capturing (very many) images from notebook based visualizations in an automated manner, among other use cases.

Running the tests

The npm tests for the module are end-to-end tests which do not attempt to install all the components required to run the tests. The tests assume the following have been installed in the environment:

• Python 3 (tested with 3.6)
• jupyterlab=2.1.2
• jupyter labextension install @jupyter-widgets/jupyterlab-manager
• ipywidgets

The test suite was built using these versions:

$ npm -v
6.14.4
$ node -v
v10.13.0

Before running the tests you must install the dependencies:

$ cd <root>/jupyter_puppeteer_helpers
$ npm install

After the external and internal dependencies have been installed run the tests like this:

$ npm run test

To watch the tests running in slow motion (not headless)

HEADLESS="false" SLOWMO=100 npm run test

To watch the a single test running by itself in slow motion, specify its name:

HEADLESS="false" SLOWMO=100 jest -t "runs a widget in an example notebook"