plugin: sort tests by topology name

This is needed in order to allow one-time topology setup and teardown.

If the tests would not be sorted by topology, we would have to run
topology setup and teardown for each test, which has its use cases
but in most majority of cases you want to setup environment for
given topology only once and then run all tests for this topology
in order to speed things up.

We will provide hooks to do both - one-time setup and per-test setup.

pytest_mh/_private/plugin.py

@@ -218,8 +218,9 @@ def pytest_collection_modifyitems(self, config: pytest.Config, items: list[pytes
         :meta private:
         """
 
-        selected = []
-        deselected = []
+        selected: list[pytest.Item] = []
+        deselected: list[pytest.Item] = []
+        mapping: dict[str, list[pytest.Item]] = {}
 
         for item in items:
             data = MultihostItemData(self.multihost, item.stash[MarkStashKey]) if self.multihost else None
@@ -229,8 +230,16 @@ def pytest_collection_modifyitems(self, config: pytest.Config, items: list[pytes
                 deselected.append(item)
                 continue
 
-            selected.append(item)
+            # Map test items by topology name so we can sort them later
+            if data is None or data.topology_mark is None:
+                mapping.setdefault("", []).append(item)
+            else:
+                mapping.setdefault(data.topology_mark.name, []).append(item)
+
+        # Sort test by topology name
+        selected = sum([y for _, y in sorted(mapping.items())], [])
 
+        # Yield result to pytest
         config.hook.pytest_deselected(items=deselected)
         items[:] = selected