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Version: 1.1


Hydra uses nox - a build automation tool - to manage tests, linting, code coverage, etc. The command nox will run all the configured sessions. List the sessions using nox -l and run specific sessions with nox -s NAME (you may need to quote the session name in some cases)

Testing with pytest​

Run pytest at the repository root to run all the Hydra core tests. To run the tests of individual plugins, use pytest plugins/NAME (The plugin must be installed).


Some plugins support fewer versions of Python than the Hydra core.

Testing with nox​

See nox -l. a few examples:

  • nox -s test_core will test Hydra core on all supported Python versions
  • nox -s "test_plugins-3.8" will test plugins on Python 3.8.
  • nox -s "test_plugins-3.8" will test plugins on Python 3.8.

The is checking some environment variables to decide what to run. For example, to test a single plugin:

$ PLUGINS=hydra_colorlog nox -s test_plugins-3.8
Operating system : Linux
NOX_PYTHON_VERSIONS : ['3.6', '3.7', '3.8', '3.9']
PLUGINS : ['hydra_colorlog']
FIX : False
nox > Running session test_plugins-3.8