#62 increase unit test coverage

flatland/core/grid/grid4.py

@@ -49,6 +49,9 @@ class Grid4Transitions(Transitions):
         # row,col delta for each direction
         self.gDir2dRC = np.array([[-1, 0], [0, 1], [1, 0], [0, -1]])
 
+        # These bits represent all the possible dead ends
+        self.maskDeadEnds = 0b0010000110000100
+
     def get_type(self):
         return np.uint16
 
@@ -210,3 +213,19 @@ class Grid4Transitions(Transitions):
 
     def get_direction_enum(self) -> IntEnum:
         return Grid4TransitionsEnum
+
+    def has_deadend(self, cell_transition):
+        """
+        Checks if one entry can only by exited by a turn-around.
+        """
+        if cell_transition & self.maskDeadEnds > 0:
+            return True
+        else:
+            return False
+
+    def remove_deadends(self, cell_transition):
+        """
+        Remove all turn-arounds (e.g. N-S, S-N, E-W,...).
+        """
+        cell_transition &= cell_transition & (~self.maskDeadEnds) & 0xffff
+        return cell_transition

flatland/core/grid/rail_env_grid.py

@@ -43,9 +43,6 @@ class RailEnvTransitions(Grid4Transitions):
             transitions=self.transition_list
         )
 
-        # These bits represent all the possible dead ends
-        self.maskDeadEnds = 0b0010000110000100
-
         # create this to make validation faster
         self.transitions_all = set()
         for index, trans in enumerate(self.transitions):
@@ -112,13 +109,3 @@ class RailEnvTransitions(Grid4Transitions):
             True or False
         """
         return cell_transition in self.transitions_all
-
-    def has_deadend(self, cell_transition):
-        if cell_transition & self.maskDeadEnds > 0:
-            return True
-        else:
-            return False
-
-    def remove_deadends(self, cell_transition):
-        cell_transition &= cell_transition & (~self.maskDeadEnds) & 0xffff
-        return cell_transition

tests/test_flatland_core_transitions.py

@@ -4,18 +4,20 @@
 """Tests for `flatland` package."""
 import numpy as np
 
+from flatland.core.grid.grid4 import Grid4Transitions
 from flatland.core.grid.grid8 import Grid8Transitions
 from flatland.core.grid.rail_env_grid import RailEnvTransitions
 from flatland.envs.env_utils import validate_new_transition
 
 
+# remove whitespace in string; keep whitespace below for easier reading
+def rw(s):
+    return s.replace(" ", "")
+
+
 def test_rotate_railenv_transition():
     rail_env_transitions = RailEnvTransitions()
 
-    # remove whitespace in string; keep whitespace below for easier reading
-    def rw(s):
-        return s.replace(" ", "")
-
     # TODO test all cases
     transition_cycles = [
         # empty cell - Case 0
@@ -68,9 +70,17 @@ def test_rotate_railenv_transition():
         # int('1100110000110011', 2),   \ #  noqa: E800
         # Case 6 - symmetrical
         # int('0101001000000010', 2),   \ #  noqa: E800
-        # Case 7 - dead end
-        # int('0010000000000000', 2),   \ #  noqa: E800
 
+        # Case 7 - dead end
+        #
+        #
+        #     |
+        [
+            int(rw('0010 0000 0000 0000'), 2),
+            int(rw('0000 0001 0000 0000'), 2),
+            int(rw('0000 0000 1000 0000'), 2),
+            int(rw('0000 0000 0000 0100'), 2),
+        ],
     ]
 
     for index, cycle in enumerate(transition_cycles):
@@ -206,3 +216,33 @@ def test_diagonal_transitions():
 
     assert (diagonal_trans_env.rotate_transition(
         south_northeast_transition, 180) == north_southwest_transition)
+
+
+def test_rail_env_has_deadend():
+    deadends = set([int(rw('0010 0000 0000 0000'), 2),
+                    int(rw('0000 0001 0000 0000'), 2),
+                    int(rw('0000 0000 1000 0000'), 2),
+                    int(rw('0000 0000 0000 0100'), 2)])
+    ret = RailEnvTransitions()
+    transitions_all = ret.transitions_all
+    for t in transitions_all:
+        expected_has_deadend = t in deadends
+        actual_had_deadend = ret.has_deadend(t)
+        assert actual_had_deadend == expected_has_deadend, \
+            "{} should be deadend = {}, actual = {}".format(t, )
+
+
+def test_rail_env_remove_deadend():
+    ret = Grid4Transitions([])
+    rail_env_deadends = set([int(rw('0010 0000 0000 0000'), 2),
+                             int(rw('0000 0001 0000 0000'), 2),
+                             int(rw('0000 0000 1000 0000'), 2),
+                             int(rw('0000 0000 0000 0100'), 2)])
+    for t in rail_env_deadends:
+        expected_has_deadend = 0
+        actual_had_deadend = ret.remove_deadends(t)
+        assert actual_had_deadend == expected_has_deadend, \
+            "{} should be deadend = {}, actual = {}".format(t, )
+
+    assert ret.remove_deadends(int(rw('0010 0001 1000 0100'), 2)) == 0
+    assert ret.remove_deadends(int(rw('0010 0001 1000 0110'), 2)) == int(rw('0000 0000 0000 0010'), 2)