docs: testing: Update contents with tox

Signed-off-by: Erik Skultety <eskultet@redhat.com>

1 files changed, 64 insertions, 10 deletions

diff --git a/docs/testing.rst b/docs/testing.rst
index 425dce6..c990683 100644
--- a/docs/testing.rst
+++ b/docs/testing.rst
@@ -2,17 +2,71 @@
 Testing
 =======
 
-This project utilizes the pytest framework. Make sure you add a new test case
-with any new logic you introduce to the lcitool code base.
-Whenever you add new package mappings the test suite will naturally fail
-because it simply doesn't know about them. In that case, just re-run the test
-suite as
+Running tests
+-------------
+This project utilizes the pytest framework. You can either run it directly
+yourself or make use of the power of tox and test in different environments.
+
+Pytest
+~~~~~~
+
+You can run a smoke check of your changes quickly with
+
+::
+
+    $ pytest
+
+For more extensive checking in different environments please consider using
+tox, see below.
+
+Tox
+~~~
+Make sure you have tox installed for this one. You can either install it
+manually or via ``dev-requirements.txt`` which will also install all
+dependencies for overall lcitool development. Once installed, simply run
+
+::
+
+    $ tox
+
+Running specific test environments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+We define a couple of test environments for tox:
+
+* ``lint`` flake8 linter
+* ``py38`` which reflects our minimum requirement for Python 3.8
+* ``py311`` which is supposed to catch early deprecations with latest Python
+
+You can select which test environment tox should execute with
+
+::
+
+    $ tox -e <test_env>
+
+
+Adding test cases
+-----------------
+Make sure you add a new test case with any new logic you introduce to the
+lcitool code base. Note that whenever you add new package mappings the test
+suite will naturally fail because it simply doesn't know about them. In that
+case, just re-run the test suite as
+
+::
+
+    $ pytest --regenerate-output
+
+or
 
 ::
 
-    $ python3 -m pytest --regenerate-output
+    $ tox -e py38 -- --regenerate-output
 
-and the expected package data sets will be updated. You can then just grab the
-changes and add them to your commit. Beware though that if you test a buggy
-code this way the tests would not be able to catch regressions since the
-"correct" test output would now match the flawed output.
+depending on what tool you prefer for testing and the expected package data
+sets will be updated automatically. You can then just grab the changes and add
+them to your commit. Beware though that if you test a buggy code this way the
+tests would not be able to catch regressions since the "correct" test output
+would now match the flawed output. Note however that when regenerating output
+with ``tox`` you **must** select a test environment with ``tox`` because
+otherwise all environments will get the ``--regenerate-output`` option which
+could make some of them fail.