add dice parser tests

tests/dice/test_dice.py

@@ -0,0 +1,44 @@
+import pytest
+
+from src.dice.dice import DiceRoller
+
+
+@pytest.fixture()
+def dice_roller():
+    return DiceRoller()
+
+
+@pytest.mark.parametrize(
+    "expression, range_min, range_max",
+    [
+        ("d20", 1, 20),
+        ("d12", 1, 12),
+        ("d10", 1, 10),
+        ("d8", 1, 8),
+        ("d6", 1, 6),
+        ("d4", 1, 4),
+        ("2d20", 2, 40),
+        ("2d12", 2, 24),
+        ("2d10", 2, 20),
+        ("2d8", 2, 16),
+        ("2d6", 2, 12),
+        ("2d4", 2, 8),
+        ("d20+1", 1, 21),
+        ("d12+1", 1, 13),
+        ("d10+1", 1, 11),
+        ("d8+1", 1, 9),
+        ("d6+1", 1, 7),
+        ("d4+1", 1, 5),
+        ("d20-1", 1, 19),
+        ("d12-1", 1, 11),
+        ("d10-1", 1, 9),
+        ("d8-1", 1, 7),
+        ("d6-1", 1, 5),
+        ("d4-1", 1, 3),
+    ],
+)
+def test_die_roll(expression, range_min, range_max, dice_roller):
+    # let the dies roll...
+    for i in range(100):
+        result = dice_roller.roll(expression)
+        assert range_min <= result <= range_max