add test on value error for new argument

Author: Florian Gardin

skrules/skope_rules.py

@@ -205,6 +205,9 @@ def fit(self, X, y, sample_weight=None):
                              " in the data, but the data contains only one"
                              " class: %r" % self.classes_[0])
 
+        if not isinstance(self.max_depth_duplication, int) and self.max_depth_duplication is not None:
+            raise ValueError("max_depth_duplication should be an integer"
+                             )
         if not set(self.classes_) == set([0, 1]):
             warn("Found labels %s. This method assumes target class to be"
                  " labeled as 1 and normal data to be labeled as 0. Any label"

skrules/tests/test_skope_rules.py

@@ -93,6 +93,7 @@ def test_skope_rules_error():
     assert_no_warnings(SkopeRules(max_samples=np.int64(2)).fit, X, y)
     assert_raises(ValueError, SkopeRules(max_samples='foobar').fit, X, y)
     assert_raises(ValueError, SkopeRules(max_samples=1.5).fit, X, y)
+    assert_raises(ValueError, SkopeRules(max_depth_duplication=1.5).fit, X, y)
     assert_raises(ValueError, SkopeRules().fit(X, y).predict, X[:, 1:])
     assert_raises(ValueError, SkopeRules().fit(X, y).decision_function,
                   X[:, 1:])