To test the functionality of the library, we make use of e2e tests (end to end tests). In this library, we spin up a headless chrome using puppeteer and interactively and programmatically tell the mouse pointer to click and drag on various elements while making assertions along the way.
We use Jest for the assertions and the interactivity is handled by puppeteer. Due to the laborious nature of writing e2e tests, there is a helper method that is provided in each test that makes interacting with the diagrams a lot easier. Using this helper, you can easily tell the mouse to drag links between nodes, select them and also easily assert information about them. The important thing here, is that this helper does not touch the model in any way, but is purely a helper for writing the tests themselves. Please make use of this helper when writing tests, as it ensure that the tests are defensive in nature, and also reduces the overhead of physically writing them.