Plotting tests

A frequent frustration in testing is the reproducibility of the plots and matplotlib’s behaviour in different environments. We have some tooling to help with this.

Viewing plots from failed tests on Azure pipelines

The fixtures check_same_image and image_comparer upload plots from failing tests so you can view them from the azure pipelines test viewer. To find these, navigate to the tests tab for your build


Select your failing test


And open the attachments tab


From here you can view and download the images which were compared, as well as a diff between them.


matplotlib.testing.setup() tries to establish a consistent environment for creating plots. Make sure it’s active!