Fix #4 and add corresponding tests

Signed-off-by: Tin Lai <[email protected]>

env.py

@@ -125,6 +125,11 @@ def __getattr__(self, attr):
         """
         return object.__getattribute__(self.visualiser, attr)
 
+    @property
+    def sampler(self):
+        """Pass through attribute access to sampler."""
+        return self.args.sampler
+
     @staticmethod
     def radian_dist(p1: np.ndarray, p2: np.ndarray):
         """Return the (possibly wrapped) distance between two vector of angles in

tests/test_env.py

@@ -0,0 +1,83 @@
+from unittest import TestCase
+
+import numpy as np
+
+import env
+import visualiser
+from planners.basePlanner import Planner
+from samplers.baseSampler import Sampler
+from main import generate_args
+from tests.common_vars import DummyPlannerClass
+from utils import planner_registry
+
+
+class TestGenerateArgs(TestCase):
+    def test_missing_argunment(self):
+        with self.assertRaises(TypeError):
+            generate_args()
+        with self.assertRaises(TypeError):
+            generate_args(planner_id="rrt")
+        with self.assertRaises(TypeError):
+            generate_args(map_fname="maps/4d.png")
+
+        # should not raise error
+        generate_args(planner_id="rrt", map_fname="maps/4d.png")
+
+        # test error if the planner id has not been registered yet
+        with self.assertRaises(ValueError):
+            generate_args(planner_id="my_planner_id", map_fname="maps/4d.png")
+
+        # test that after the planner id is registered, it will work.
+        planner_registry.register_planner(
+            planner_id="my_planner_id",
+            planner_class=DummyPlannerClass,
+            sampler_id="random",
+        )
+        generate_args(planner_id="my_planner_id", map_fname="maps/4d.png")
+
+    def test_actual_planning(self):
+        visualiser.VisualiserSwitcher.choose_visualiser("base")
+        args = generate_args(
+            planner_id="rrt",
+            map_fname="maps/test.png",
+            start_pt=np.array([25, 123]),
+            goal_pt=np.array([225, 42]),
+        )
+        args.no_display = True
+
+        e = env.Env(args, fixed_seed=0)
+        ori_method = e.planner.run_once
+
+        # prepare an exception to escape from the planning loop
+        class PlanningSuccess(Exception):
+            pass
+
+        def planner_run_once_with_side_effect(*args, **kwargs):
+            # pass through to planner
+            ori_method(*args, **kwargs)
+            if e.planner.c_max < float("inf"):
+                raise PlanningSuccess()
+
+        # patch the planner run_once such that it will terminates as soon as the
+        # planning problem is finished.
+        e.planner.run_once = planner_run_once_with_side_effect
+        with self.assertRaises(PlanningSuccess):
+            e.run()
+
+    def test_get_attribute(self):
+        visualiser.VisualiserSwitcher.choose_visualiser("pygame")
+        args = generate_args(
+            planner_id="rrt",
+            map_fname="maps/test.png",
+            start_pt=np.array([25, 123]),
+            goal_pt=np.array([225, 42]),
+        )
+        args.no_display = True
+
+        e = env.Env(args, fixed_seed=0)
+
+        # test get planner
+        assert isinstance(e.planner, Planner)
+
+        # test get sampler
+        assert isinstance(e.sampler, Sampler)