Tests for class_load_container v2 (#247)

* Tests for class_load_container v2
  - file as same name as class
  - useless numpy conversations removed
  - switched to built-in type tests
  - human readable tests included
* ruff
* removed dupicate empty list
* load_aggregator: collections.abc.Sequence

---------

Co-authored-by: Dominique Lasserre <lasserre.d@gmail.com>

tests/test_load_aggregator.py

@@ -0,0 +1,39 @@
+import pytest
+
+from akkudoktoreos.prediction.load_aggregator import LoadAggregator
+
+
+def test_initialization():
+    aggregator = LoadAggregator()
+    assert aggregator.prediction_hours == 24
+    assert aggregator.loads == {}
+
+
+def test_add_load_valid():
+    aggregator = LoadAggregator(prediction_hours=3)
+    aggregator.add_load("Source1", [10.0, 20.0, 30.0])
+    assert aggregator.loads["Source1"] == [10.0, 20.0, 30.0]
+
+
+def test_add_load_invalid_length():
+    aggregator = LoadAggregator(prediction_hours=3)
+    with pytest.raises(ValueError, match="Total load inconsistent lengths in arrays: Source1 2"):
+        aggregator.add_load("Source1", [10.0, 20.0])
+
+
+def test_calculate_total_load_empty():
+    aggregator = LoadAggregator()
+    assert aggregator.calculate_total_load() == []
+
+
+def test_calculate_total_load():
+    aggregator = LoadAggregator(prediction_hours=3)
+    aggregator.add_load("Source1", [10.0, 20.0, 30.0])
+    aggregator.add_load("Source2", [5.0, 15.0, 25.0])
+    assert aggregator.calculate_total_load() == [15.0, 35.0, 55.0]
+
+
+def test_calculate_total_load_single_source():
+    aggregator = LoadAggregator(prediction_hours=3)
+    aggregator.add_load("Source1", [10.0, 20.0, 30.0])
+    assert aggregator.calculate_total_load() == [10.0, 20.0, 30.0]