Clean some duplicated and unused code (frequenz-floss#1088)

Author: llucax

src/frequenz/sdk/microgrid/component_graph.py

@@ -1065,28 +1065,3 @@ def _validate_leaf_components(self) -> None:
             raise InvalidGraphError(
                 f"Leaf components with graph successors: {with_successors}"
             )
-
-
-def _correct_graph_errors(graph: _MicrogridComponentGraph) -> None:
-    """Attempt to correct errors in component graph data.
-
-    For now, this handles just the special case of graph data that is missing an
-    explicit grid endpoint, but has an implicit one due to one or more
-    components having node 0 as their parent.
-
-    Args:
-        graph: the graph whose data to correct (will be updated in place)
-    """
-    # Check if there is an implicit grid endpoint with id == 0.
-    # This is an expected case from the API: that no explicit
-    # grid endpoint will be provided, but that components connected
-    # to the grid endpoint will have node 0 as their predecessor.
-    # pylint: disable=protected-access
-    if (
-        graph._graph.has_node(0)
-        and graph._graph.in_degree(0) == 0
-        and graph._graph.out_degree(0) > 0
-        and "type" not in graph._graph.nodes[0]
-    ):
-        graph._graph.add_node(0, **asdict(Component(0, ComponentCategory.GRID)))
-    # pylint: enable=protected-access

src/frequenz/sdk/microgrid/connection_manager.py

@@ -155,8 +155,7 @@ async def _update_api(self, server_url: str) -> None:
         await super()._update_api(server_url)  # pylint: disable=protected-access
 
         self._api = ApiClient(server_url)
-        self._metadata = await self._api.metadata()
-        await self._graph.refresh_from_api(self._api)
+        await self._initialize()
 
     async def _initialize(self) -> None:
         self._metadata = await self._api.metadata()

tests/microgrid/test_graph.py

@@ -1426,81 +1426,6 @@ def test__validate_leaf_components(self) -> None:
         graph._graph.add_edges_from([(1, 2), (1, 3), (1, 4)])
         graph._validate_leaf_components()
 
-    def test_graph_correction(self) -> None:
-        """Test the graph correction functionality."""
-        # Simple test cases for our built-in graph correction
-        # functionality.  We test only with `refresh_from`:
-        # for `refresh_from_api` it suffices to test that any
-        # provided `correct_errors` callback gets invoked,
-        # which is already done in `test_refresh_from_api`.
-
-        graph = gr._MicrogridComponentGraph()
-        assert set(graph.components()) == set()
-        assert list(graph.connections()) == []
-
-        # valid graph data: no correction will be applied
-        graph.refresh_from(
-            components={
-                Component(1, ComponentCategory.GRID),
-                Component(2, ComponentCategory.METER),
-            },
-            connections={Connection(1, 2)},
-            correct_errors=gr._correct_graph_errors,
-        )
-        expected = {
-            Component(1, ComponentCategory.GRID),
-            Component(2, ComponentCategory.METER),
-        }
-        assert len(graph.components()) == len(expected)
-        assert set(graph.components()) == expected
-        assert list(graph.connections()) == [Connection(1, 2)]
-
-        # invalid graph data that (for now at least)
-        # cannot be corrected
-        with pytest.raises(gr.InvalidGraphError):
-            graph.refresh_from(
-                components={Component(4, ComponentCategory.METER)},
-                connections={Connection(3, 4)},
-                correct_errors=gr._correct_graph_errors,
-            )
-
-        # graph is still in last known good state
-        assert len(graph.components()) == len(expected)
-        assert set(graph.components()) == expected
-        assert list(graph.connections()) == [Connection(1, 2)]
-
-        # invalid graph data where there is no grid
-        # endpoint but a node has the magic value 0
-        # for its predecessor
-
-        # without the callback, this is identified as
-        # invalid
-        with pytest.raises(gr.InvalidGraphError):
-            graph.refresh_from(
-                components={Component(8, ComponentCategory.METER)},
-                connections={Connection(0, 8)},
-            )
-
-        # graph is still in last known good state
-        assert len(graph.components()) == len(expected)
-        assert set(graph.components()) == expected
-        assert list(graph.connections()) == [Connection(1, 2)]
-
-        # with the callback, this can be corrected
-        graph.refresh_from(
-            components={Component(8, ComponentCategory.METER)},
-            connections={Connection(0, 8)},
-            correct_errors=gr._correct_graph_errors,
-        )
-        expected = {
-            Component(8, ComponentCategory.METER),
-            Component(0, ComponentCategory.GRID),
-        }
-        assert len(graph.components()) == len(expected)
-        assert set(graph.components()) == expected
-
-        assert list(graph.connections()) == [Connection(0, 8)]
-
 
 class TestComponentTypeIdentification:
     """Test the component type identification methods in the component graph."""