Update test docs (#2901)

* Update unit tests paragraph with regression data

* Update lfs command

* Fix syntax

* Update regression data step.

* Fix reference

* Update note

* Add a note about migrating to regression data

* Removing integration tests section

* Update repo location line

docs/contributing/development/running_tests.rst

@@ -22,39 +22,38 @@ tests, you can run this with:
     > pytest tardis
 
 
-Running the more advanced unit tests requires TARDIS Reference data that can be
+Running the more advanced unit tests requires TARDIS Regression data that can be
 downloaded
-(`tardis-refdata <https://github.com/tardis-sn/tardis-refdata>`_).
+(`tardis-regression-data <https://github.com/tardis-sn/tardis-regression-data>`_).
 `Git LFS <https://www.atlassian.com/git/tutorials/git-lfs>`_ is used
-to download the large refdata files in the tardis-refdata repository.
+to download the large regression data files in the tardis-regression-data repository.
 
-However, it is not required to download the entire repository. Firstly it is
-important to identify the refdata files that are needed. Sometimes, it is possible
-that a preused fixture that is also being used in the current tests is using some
-refdata. So, it is advised to check for such cases beforehand.
-
-After identifying the refdata files to be used in the unit tests, those particular
-files can be downloaded using ``git lfs`` 
 
 .. code-block:: shell
 
-    > git lfs pull --include=filename
+    > git lfs pull
+
 
-It is important to maintain the same directory structure as the tardis-refdata repo
-i.e. the lfs files should be in the same directory tree exactly as in tardis-refdata
-repository.
+The ``tardis-regression-data`` repository should be located outside of the main ``tardis`` repository, rather than being nested within it.
+
+.. warning::
+    We have migrated from ``tardis-refdata`` to``tardis-regression-data``.
 
 Finally, the tests can be run using the following command
 
 .. code-block:: shell
 
-    > pytest tardis --tardis-refdata=/path/to/tardis-refdata/
+    > pytest tardis --tardis-regression-data=/path/to/tardis-regression-data/
 
 Or, to run tests for a particular file or directory
 
 .. code-block:: shell
 
-    > pytest tardis/path/to/test_file_or_directory --tardis-refdata=/path/to/tardis-refdata/
+    > pytest tardis/path/to/test_file_or_directory --tardis-regression-data=/path/to/tardis-regression-data/
+
+
+.. warning::
+    In some cases you might have to update the regression data. The steps to update the regression data are outlined in the :ref:`update regression-data`.
 
 .. warning::
     The `tests workflow <https://github.com/tardis-sn/tardis/blob/master/.github/workflows/tests.yml>`_ runs on 
@@ -74,36 +73,4 @@ You can generate Plasma Reference by the following command:
 .. code-block:: shell
 
     > pytest -rs tardis/plasma/tests/test_complete_plasmas.py 
-    --tardis-refdata="/path/to/tardis-refdata/" --generate-reference
-
-Running the Integration Tests
-=============================
-
-These tests require reference files against which the results of the various
-tardis runs are tested. So you first need to either download the current
-reference files (`here <https://github.com/tardis-sn/tardis-refdata>`_)
-or generate new ones.
-
-Both of these require a configuration file for the integration tests:
-
-.. literalinclude:: integration.yml
-    :language: yaml
-
-Inside the atomic data directory there needs to be atomic data for each of
-the setups that are provided in the ``test_integration`` folder.
-If no references are given, the first step is to generate them.
-The ``--less-packets`` option is useful for debugging purposes and will just
-use very few packets to generate the references and thus make the process much
-faster --- THIS IS ONLY FOR DEBUGGING PURPOSES. The ``-s`` option ensures that
-TARDIS prints out the progress:
-
-.. code-block:: shell
-
-    > pytest --integration=integration.yml -m integration --generate-reference --less-packets
-
-To run the test after having run the ``--generate-references``, all that is
-needed is:
-
-.. code-block:: shell
-
-    > pytest --integration=integration.yml -m integration --less-packets --remote-data
+    --tardis-regression-data="/path/to/tardis-regression-data/" --generate-reference