DOC: Fix and extend docstrings of linkahead.utils.register_tests

src/linkahead/utils/register_tests.py

@@ -18,44 +18,62 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program. If not, see <https://www.gnu.org/licenses/>.
-
-import linkahead as db
-from linkahead import administration as admin
-
-"""
-This module implements a registration procedure for integration tests which
+"""This module implements a registration procedure for integration tests which
 need a running LinkAhead instance.
 
-It ensures that tests do not accidentally overwrite data in real LinkAhead
-instances, as it checks whether the running LinkAhead instance is actually the
-correct one, that
-should be used for these tests.
-
-The test files have to define a global variable TEST_KEY which must be unique
-for each test using
+It ensures that tests do not accidentally overwrite data in real
+LinkAhead instances, as it checks whether the running LinkAhead
+instance is actually the correct one, that should be used for these
+tests.
 
-set_test_key("ABCDE")
+The test files have to define a global variable ``TEST_KEY`` which
+must be unique for each test using
+:py:meth:`~linkahead.utils.register_tests.set_test_key`.
 
 The test procedure (invoked by pytest) checks whether a registration
 information is stored in one of the server properties or otherwise
-- offers to register this test in the currently running database ONLY if this
-  is empty.
+
+- offers to register this test in the currently running database ONLY if this is
+  empty.
 - fails otherwise with a RuntimeError
 
-NOTE: you probably need to use pytest with the -s option to be able to
-      register the test interactively. Otherwise, the server property has to be
-      set before server start-up in the server.conf of the LinkAhead server.
+.. note::
+
+    you probably need to use pytest with the -s option to be able to
+    register the test interactively. Otherwise, the server property
+    has to be set before server start-up in the server.conf of the
+    LinkAhead server.
 
 This module is intended to be used with pytest.
 
-There is a pytest fixture "clear_database" that performs the above mentioned
-checks and clears the database in case of success.
+There is a pytest fixture
+:py:meth:`~linkahead.utils.register_tests.clear_database` that
+performs the above mentioned checks and clears the database in case of
+success.
+
 """
 
+import linkahead as db
+from linkahead import administration as admin
+
 TEST_KEY = None
 
 
-def set_test_key(KEY):
+def set_test_key(KEY: str):
+    """Set the global ``TEST_KEY`` variable to `KEY`. Afterwards, if
+    `KEY` matches the ``_CAOSDB_INTEGRATION_TEST_SUITE_KEY`` server
+    environment variable, mehtods like :py:meth:`clear_database` can
+    be used. Call this function in the beginning of your test file.
+
+    Parameters
+    ----------
+    KEY : str
+        key with which the test using this function is registered and
+        which is checked against the
+        ``_CAOSDB_INTEGRATION_TEST_SUITE_KEY`` server environment
+        variable.
+
+    """
     global TEST_KEY
     TEST_KEY = KEY
 
@@ -122,10 +140,14 @@ try:
 
     @pytest.fixture
     def clear_database():
-        """Remove Records, RecordTypes, Properties, and Files ONLY IF the LinkAhead
-        server the current connection points to was registered with the appropriate key.
+        """Remove Records, RecordTypes, Properties, and Files ONLY IF
+        the LinkAhead server the current connection points to was
+        registered with the appropriate key using
+        :py:meth:`set_test_key`.
+
+        PyTestInfo Records and the corresponding RecordType and
+        Property are preserved.
 
-        PyTestInfo Records and the corresponding RecordType and Property are preserved.
         """
         _assure_test_is_registered()
         yield _clear_database()  # called before the test function