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Browser Testing


Wave native testing tools are no longer supported. Use modern alternatives like Playwright.

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

(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!