added input validation for all sensible parameters with tests

Author: direkkakkar319-ops

pyaptamer/mcts/_algorithm.py

@@ -24,11 +24,13 @@ class MCTS(BaseObject):
     ----------
     states : list[str], optional, default=None
         Possible values for the nodes. Underscores indicate whether the values are
-        supposed to be prepended or appended to the sequence.
+        supposed to be prepended or appended to the sequence. Must be non-empty and
+        contain unique entries.
     depth : int, optional, default=20
-        Maximum depth of the search tree, also the length of the generated sequences.
+        Maximum depth of the search tree, also the length of the generated
+        sequences. Must be >= 1.
     n_iterations : int, optional, default=1000
-        Number of iterations per round for the MCTS algorithm.
+        Number of iterations per round for the MCTS algorithm. Must be >= 1.
     experiment : BaseAptamerEval, optional, default=None
         An instance of an experiment class definingthe goal function for the algorithm.
 
@@ -74,17 +76,23 @@ def __init__(
         n_iterations: int = 1000,
         experiment=None,
     ) -> None:
+        if depth < 1:
+            raise ValueError(f"`depth` must be >= 1, got {depth}.")
         if n_iterations < 1:
             raise ValueError(f"`n_iterations` must be >= 1, got {n_iterations}.")
 
+        if states is None:
+            states = ["A_", "C_", "G_", "U_", "_A", "_C", "_G", "_U"]
+        elif not states:
+            raise ValueError("`states` must contain at least one entry.")
+        elif len(states) != len(set(states)):
+            raise ValueError("`states` must contain unique entries.")
+
         self.experiment = experiment
         self.depth = depth
         self.n_iterations = n_iterations
 
         super().__init__()
-
-        if states is None:
-            states = ["A_", "C_", "G_", "U_", "_A", "_C", "_G", "_U"]
         self.states = states
 
         self.root = TreeNode(

pyaptamer/mcts/tests/test_mcts.py

@@ -241,12 +241,28 @@ def mcts(request):
 class TestMCTS:
     """Tests for the MCTS() class."""
 
+    @pytest.mark.parametrize("depth", [0, -1])
+    def test_init_invalid_depth(self, depth):
+        """Check invalid depths are rejected early."""
+        with pytest.raises(ValueError, match=r"`depth` must be >= 1"):
+            MCTS(depth=depth)
+
     @pytest.mark.parametrize("n_iterations", [0, -1])
     def test_init_invalid_iterations(self, n_iterations):
         """Check invalid iteration counts are rejected early."""
         with pytest.raises(ValueError, match=r"`n_iterations` must be >= 1"):
             MCTS(n_iterations=n_iterations)
 
+    def test_init_empty_states(self):
+        """Check an empty search space is rejected early."""
+        with pytest.raises(ValueError, match=r"`states` must contain at least one"):
+            MCTS(states=[])
+
+    def test_init_duplicate_states(self):
+        """Check duplicate states are rejected early."""
+        with pytest.raises(ValueError, match=r"`states` must contain unique entries"):
+            MCTS(states=["A_", "A_"])
+
     def test_reset(self, mcts):
         """Check correct reset of the inner state."""
         # modify its inner state