Added tests for split rules

Author: velochy

tests/test_split_rules.py

@@ -0,0 +1,24 @@
+import numpy as np
+
+from pymc_bart.split_rules import ContinuousSplitRule, OneHotSplitRule, SubsetSplitRule
+import pytest
+
+@pytest.mark.parametrize(
+    argnames="Rule",
+    argvalues=[ContinuousSplitRule, OneHotSplitRule, SubsetSplitRule],
+    ids=["continuous", "one_hot", "subset"],
+)
+def test_split_rule(Rule):
+
+    # Should return None if only one available value to pick from
+    assert Rule.get_split_value(np.zeros(1)) is None
+
+    # get_split should return a value divide can use
+    available_values = np.arange(10).astype(float)
+    sv = Rule.get_split_value(available_values)
+    left = Rule.divide(available_values,sv)
+
+    # divide should return a boolean numpy array
+    # This de facto ensures it is a binary split
+    assert len(left) == len(available_values)
+    assert left.dtype == 'bool'