In November 2021 Astronomer switched from using the helm-unittest software to using a pytest setup for testing the astronomer/airflow-chart helm chart. This mirrors the Airflow community's effort in chart testing. There are many good reasons reasons for choosing pytest over the more helm-specific helm-unittest software:

• pytest skills are something you can learn and take with you pretty much anywhere.
• pytest skills are something engineers can bring to the table without having any inside knowledge of Astronomer, Airflow, kubernetes or helm.
• pytest is extensively documented, has many useful plugins, and is debuggable though all the normal python testing tools.

See astronomer/astronomer/tests/chart_tests/README.md for a tutorial on how to write these tests.