Plotly Dash Testing

[mgiammar]

These are some notes on how Dash testing needs to be set up and run. Dash testing uses GoogleChrome by default and these instructions also use GoogleChrome. See the Dash documentation for more info on the testing api.

Here are the steps to install and run a Dash test using the built in functionality. Note: This was done on MacOS 11.5 intel with Python 3.7.10 and Dash 1.21.0.

1. Open a new terminal window and navigate to your Python environment for mrsimulator-app.
2. Type pip install 'dash[testing]' and press enter. This will install optional dependencies essential for running a dash test.
3. Go to https://chromedriver.chromium.org and download the latest stable version of ChromeDriver. The version of ChromeDriver must match the version of GoogleChrome installed on your machine. Here is info on how to find your GoogleChrome version.
4. The downloaded file should be named chromedriver. This file needs to be added to your PATH.
   • Info on moving/linking an executable to your PATH (Recommended)
   • OR
   • Info on adding a directory to your PATH variable.
5. Navigate to the mrsimulator-app directory.
6. In terminal run pytest dash_testing/test_example.py. An Unidentified Developer message should pop up. Go to System Preferences > Security & Privacy > General and press Allow Anyway. The pytest will fail. This is expected.
7. Run pytest dash_testing/test_example.py again. This should open mrsimulator-app and wait on the landing page for a few seconds.