feat: Engine pie – Tortensegmente mit Übrige-Regel und SVG-Pfaden (A13-T3)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

finance/tests/test_pie.py

@@ -0,0 +1,76 @@
+from decimal import Decimal
+
+import pytest
+
+from app.engine.pie import UEBRIGE, pie_slices
+
+D = Decimal
+
+
+def test_leer_und_nullwerte():
+    assert pie_slices([]) == []
+    assert pie_slices([("A", D("0")), ("B", D("-5"))]) == []
+
+
+def test_segmente_lueckenlos_und_anteile():
+    sl = pie_slices([("C", D("20")), ("A", D("50")), ("B", D("30"))])
+    assert [s.label for s in sl] == ["A", "B", "C"]
+    assert [s.color for s in sl] == ["s1", "s2", "s3"]
+    assert [s.share for s in sl] == [D("50.0"), D("30.0"), D("20.0")]
+    assert sl[0].start == 0.0 and sl[-1].end == pytest.approx(1.0)
+    for a, b in zip(sl, sl[1:]):
+        assert a.end == pytest.approx(b.start)
+    assert sl[0].path.startswith("M 0 0 L 0.0000 -1.0000 A 1 1 0 0 1 ")
+
+
+def test_large_arc_flag():
+    a, b = pie_slices([("A", D("70")), ("B", D("30"))])
+    assert " A 1 1 0 1 1 " in a.path
+    assert " A 1 1 0 0 1 " in b.path
+
+
+def test_einzelsegment_ist_vollkreis():
+    (s,) = pie_slices([("A", D("12.34"))])
+    assert s.path is None and s.share == D("100.0") and s.color == "s1"
+
+
+def test_kleine_werte_zu_uebrige():
+    sl = pie_slices([("A", D("95")), ("B", D("2")), ("C", D("2")), ("D", D("1"))])
+    assert [s.label for s in sl] == ["A", UEBRIGE]
+    u = sl[1]
+    assert (u.value, u.color, u.merged, u.members) == (D("5"), "uebrige", True, ("B", "C", "D"))
+
+
+def test_einzelner_kleiner_wert_behaelt_namen():
+    sl = pie_slices([("A", D("98")), ("B", D("2"))])
+    assert [(s.label, s.color, s.merged) for s in sl] == [("A", "s1", False), ("B", "uebrige", False)]
+
+
+def test_hoechstens_acht_benannte_segmente():
+    sl = pie_slices([(f"K{i}", D("10")) for i in range(10)], rest=D("5"),
+                    rest_label="Frei verfügbar")
+    assert [s.color for s in sl] == ["s1", "s2", "s3", "s4", "s5", "s6", "s7", "s8",
+                                     "uebrige", "frei"]
+    assert sl[-2].merged and sl[-2].members == ("K8", "K9")
+
+
+def test_acht_kategorien_ohne_uebrige():
+    sl = pie_slices([(f"K{i}", D("10")) for i in range(8)])
+    assert [s.color for s in sl] == [f"s{i}" for i in range(1, 9)]
+    assert not any(s.merged for s in sl)
+
+
+def test_rest_wird_nie_zusammengefasst():
+    sl = pie_slices([("A", D("99.5"))], rest=D("0.5"), rest_label="Frei verfügbar")
+    assert [(s.label, s.color, s.merged) for s in sl] == [("A", "s1", False), ("Frei verfügbar", "frei", False)]
+    assert sl[1].share == D("0.5")
+
+
+def test_nur_rest_ist_vollkreis():
+    (s,) = pie_slices([], rest=D("100"), rest_label="Frei verfügbar")
+    assert (s.label, s.color, s.path) == ("Frei verfügbar", "frei", None)
+
+
+def test_rest_none_oder_null_ignoriert():
+    assert len(pie_slices([("A", D("1"))], rest=None)) == 1
+    assert len(pie_slices([("A", D("1"))], rest=D("0"), rest_label="X")) == 1