Redesign access to migrogrid.grid()

RELEASE_NOTES.md

@@ -8,6 +8,10 @@ This version ships an experimental version of the **Power Manager**, adds prelim
 
 - `microgrid.battery_pool()` method now accepts a priority value.
 
+- `microgrid.grid()`
+
+  * Similar to `microgrid.battery_pool()`, the Grid is now similarily accessed.
+
 - `BatteryPool`'s control methods
 
   * Original methods `{set_power/charge/discharge}` are now replaced by `propose_{power/charge/discharge}`

src/frequenz/sdk/microgrid/__init__.py

@@ -123,8 +123,15 @@
 """  # noqa: D205, D400
 
 from ..actor import ResamplerConfig
-from . import _data_pipeline, client, component, connection_manager, fuse, grid
-from ._data_pipeline import battery_pool, ev_charger_pool, frequency, logical_meter
+from . import _data_pipeline, client, component, connection_manager, fuse
+from ._data_pipeline import (
+    battery_pool,
+    ev_charger_pool,
+    frequency,
+    grid,
+    logical_meter,
+)
+from ._grid import initialize as initialize_grid
 
 
 async def initialize(host: str, port: int, resampler_config: ResamplerConfig) -> None:
@@ -139,7 +146,7 @@ async def initialize(host: str, port: int, resampler_config: ResamplerConfig) ->
 
     api_client = connection_manager.get().api_client
     components = await api_client.components()
-    grid.initialize(components)
+    initialize_grid(components)
 
     await _data_pipeline.initialize(resampler_config)
 

src/frequenz/sdk/microgrid/_data_pipeline.py

@@ -22,6 +22,8 @@
 from ..microgrid.component import Component
 from ..timeseries._grid_frequency import GridFrequency
 from . import connection_manager
+from ._grid import Grid
+from ._grid import get as get_grid
 from .component import ComponentCategory
 
 _logger = logging.getLogger(__name__)
@@ -186,6 +188,18 @@ def ev_charger_pool(
             )
         return self._ev_charger_pools[key]
 
+    def grid(
+        self,
+    ) -> Grid | None:
+        """Return the grid instance.
+
+        If a Grid instance doesn't exist, a new one is created and returned.
+
+        Returns:
+            A Grid instance.
+        """
+        return get_grid()
+
     def battery_pool(
         self,
         battery_ids: abc.Set[int] | None = None,
@@ -454,6 +468,15 @@ def battery_pool(
     return _get().battery_pool(battery_ids, name, priority)
 
 
+def grid() -> Grid | None:
+    """Return the grid instance.
+
+    Returns:
+        The Grid instance.
+    """
+    return _get().grid()
+
+
 def _get() -> _DataPipeline:
     if _DATA_PIPELINE is None:
         raise RuntimeError(

tests/microgrid/test_grid.py

@@ -3,14 +3,13 @@
 
 """Tests for the `Grid` module."""
 
-from frequenz.sdk import microgrid
+from frequenz.sdk.microgrid import _grid
 from frequenz.sdk.microgrid.component import Component, ComponentCategory, GridMetadata
 from frequenz.sdk.microgrid.fuse import Fuse
-from frequenz.sdk.microgrid.grid import Grid
 from frequenz.sdk.timeseries import Current
 
 
-async def test_grid() -> None:
+async def test_grid_1() -> None:
     """Test the grid connection module."""
     # The tests here need to be in this exact sequence, because the grid connection
     # is a singleton. Once it gets created, it stays in memory for the duration of
@@ -21,15 +20,29 @@ async def test_grid() -> None:
         Component(2, ComponentCategory.METER),
     ]
 
-    microgrid.grid.initialize(components)
-
-    grid = microgrid.grid.get()
+    _grid.initialize(components)
+    grid = _grid.get()
     assert grid is None
 
-    # validate that the microgrid initialization fails when there are multiple
-    # grid connection points.
+
+def _create_fuse() -> Fuse:
+    """Create a fuse with a fixed current.
+
+    Returns:
+        Fuse: The fuse.
+    """
     fuse_current = Current.from_amperes(123.0)
     fuse = Fuse(fuse_current)
+    return fuse
+
+
+async def test_grid_2() -> None:
+    """Test the grid connection module, slightly more complex.
+
+    Validate that the microgrid initialization fails
+    when there are multiple grid connection points.
+    """
+    fuse = _create_fuse()
 
     components = [
         Component(1, ComponentCategory.GRID, None, GridMetadata(fuse)),
@@ -38,29 +51,27 @@ async def test_grid() -> None:
     ]
 
     try:
-        microgrid.grid.initialize(components)
-        assert False, "Expected microgrid.grid.initialize to raise a RuntimeError."
+        _grid.initialize(components)
+        assert False, "Expected microgrid.grid() to raise a RuntimeError."
     except RuntimeError:
         pass
 
-    grid = microgrid.grid.get()
-    assert grid is None
 
-    # validate that microgrids with one grid connection are accepted.
+async def test_grid_3() -> None:
+    """Validate that microgrids with one grid connection are accepted."""
     components = [
-        Component(1, ComponentCategory.GRID, None, GridMetadata(fuse)),
+        Component(1, ComponentCategory.GRID, None, GridMetadata(_create_fuse())),
         Component(2, ComponentCategory.METER),
     ]
 
-    microgrid.grid.initialize(components)
-
-    grid = microgrid.grid.get()
+    _grid.initialize(components)
+    grid = _grid.get()
     assert grid is not None
 
     expected_fuse_current = Current.from_amperes(123.0)
     expected_fuse = Fuse(expected_fuse_current)
 
-    assert grid == Grid(fuse=expected_fuse)
+    assert grid == _grid.Grid(fuse=expected_fuse)
 
     fuse_current = grid.fuse.max_current
     assert fuse_current == expected_fuse_current