init

tests/test_category_tree.py

@@ -0,0 +1,64 @@
+from common_cents.category_tree import build_category_tree
+
+
+def _by_name(nodes):
+    return {n.name: n for n in nodes}
+
+
+def test_flat_paths():
+    nodes = build_category_tree({"Food": 1000, "Travel": 500})
+    by_name = _by_name(nodes)
+    assert set(by_name) == {"Food", "Travel"}
+    assert by_name["Food"].self_total == 1000
+    assert by_name["Food"].total() == 1000
+
+
+def test_nested_paths_roll_up():
+    nodes = build_category_tree(
+        {"Food": 1000, "Food:Restaurants": 2000, "Food:Restaurants:Sushi": 500}
+    )
+    food = _by_name(nodes)["Food"]
+    assert food.self_total == 1000
+    assert food.total() == 3500
+    rest = food.children["Restaurants"]
+    assert rest.self_total == 2000
+    assert rest.total() == 2500
+
+
+def test_intermediate_ancestors_have_zero_self_total():
+    nodes = build_category_tree({"A:B:C": 100})
+    a = _by_name(nodes)["A"]
+    assert a.self_total == 0
+    assert a.total() == 100
+    assert a.children["B"].self_total == 0
+    assert a.children["B"].children["C"].self_total == 100
+
+
+def test_prev_totals_separate_from_current():
+    nodes = build_category_tree({"Food": 100}, prev_totals={"Food": 200, "Travel": 50})
+    by_name = _by_name(nodes)
+    assert by_name["Food"].self_total == 100
+    assert by_name["Food"].self_prev_total == 200
+    # Travel exists only in prev — appears in tree.
+    assert by_name["Travel"].self_total == 0
+    assert by_name["Travel"].self_prev_total == 50
+
+
+def test_extra_paths_create_empty_nodes():
+    nodes = build_category_tree({}, extra_paths=["Food:Restaurants"])
+    food = _by_name(nodes)["Food"]
+    assert food.total() == 0
+    assert "Restaurants" in food.children
+
+
+def test_empty_inputs():
+    assert build_category_tree({}) == []
+    assert build_category_tree({}, {}) == []
+
+
+def test_blank_segments_skipped():
+    """A path like ``::A`` should not create empty-named nodes."""
+    nodes = build_category_tree({"::Food": 100})
+    by_name = _by_name(nodes)
+    assert "" not in by_name
+    assert "Food" in by_name