bugfix #141: check_path_exists and tests

flatland/core/transition_map.py

@@ -312,7 +312,7 @@ class GridTransitionMap(TransitionMap):
             tmp = tmp >> 1
         return nbits == 1
 
-    def _path_exists(self, start, direction, end):
+    def check_path_exists(self, start, direction, end):
         # print("_path_exists({},{},{}".format(start, direction, end))
         # BFS - Check if a path exists between the 2 nodes
 

flatland/envs/schedule_generators.py

@@ -183,8 +183,8 @@ def random_schedule_generator(speed_ratio_map: Mapping[float, float] = None) ->
                 valid_starting_directions = []
                 for m in valid_movements:
                     new_position = get_new_position(agents_position[i], m[1])
-                    if m[0] not in valid_starting_directions and rail._path_exists(new_position, m[0],
-                                                                                   agents_target[i]):
+                    if m[0] not in valid_starting_directions and rail.check_path_exists(new_position, m[0],
+                                                                                        agents_target[i]):
                         valid_starting_directions.append(m[0])
 
                 if len(valid_starting_directions) == 0:

tests/test_flatland_core_transition_map.py

@@ -63,7 +63,7 @@ def check_path(env, rail, position, direction, target, expected, rendering=False
         renderer = RenderTool(env, gl="PILSVG")
         renderer.render_env(show=True, show_observations=False)
         input("Continue?")
-    assert rail._path_exists(agent.position, agent.direction, agent.target) == expected
+    assert rail.check_path_exists(agent.position, agent.direction, agent.target) == expected
 
 
 def test_path_exists(rendering=False):