Browser Testing

Wave supports authoring functional tests in Python for the Cypress test framework. This feature lets you automate browser-based point-and-click tests for your app.


Step 1: Install Node.js

Install a recent version of Node.js.

Step 2: Set up Cypress

Using your terminal, go to your Wave installation's test directory and install Cypress

$ cd $HOME/wave/test
$ npm install

Writing a test

See the Wizard example to understand how to author tests for your interactive app. Specifically, note how the @cypress attribute is used. Refer to the Cypress API to learn how to author assertions.

from h2o_wave import cypress
@cypress('Walk through the wizard')
def test_wizard(cy):
cy.locate('text').should('contain.text', 'What is your name?')
cy.locate('text').should('contain.text', 'Hi Fred! How do you feel right now?')
cy.locate('text').should('contain.text', 'What a coincidence, Fred! I feel quirky too!')

To escape Cypress function names that overlap with Python's reserved keywords, prefix the name with an underscore _. For example, use cy._as() instead of

Running your test

Step 1: Start the Cypress test runner

$ cd $HOME/wave/test
$ ./node_modules/.bin/cypress open

Step 2: Start the Wave server and your app as usual

$ ./waved
(venv) $ wave run --no-reload examples.wizard

Step 3: Translate your Python tests to Javascript

To translate your Python tests to Javascript, execute the Python module or file containing your tests like this:

$ CYPRESS_INTEGRATION_TEST_DIR=$HOME/wave/test/cypress/integration ./venv/bin/python examples/

The CYPRESS_INTEGRATION_TEST_DIR environment variable indicates where the Wave SDK should write translated files to. This must be set to the cypress/integration directory.

Alternatively, you can set the CYPRESS_INTEGRATION_TEST_DIR environment variable in your shell (or IDE) to simplify running your test file:

$ export CYPRESS_INTEGRATION_TEST_DIR=$HOME/wave/test/cypress/integration
$ ./venv/bin/python examples/

Step 4: Run your tests

At this point, you should find all your tests displayed in the Cypress UI. Simply click on a test to run it. Happy testing!