fixes bugs in timeflip and reflect

nathanlct · Jul 29, 2021 · de356da · de356da
1 parent a8004a0
commit de356da
Show file tree

Hide file tree

Showing 2 changed files with 58 additions and 7 deletions.
diff --git a/reeds_shepp.py b/reeds_shepp.py
@@ -18,6 +18,7 @@
 from utils import *
 import math
 from enum import Enum
+from dataclasses import dataclass, replace
 
 
 class Steering(Enum):
@@ -31,11 +32,11 @@ class Gear(Enum):
     BACKWARD = -1
 
 
+@dataclass
 class PathElement:
-    def __init__(self, param, steering, gear):
-        self.param = param
-        self.steering = steering
-        self.gear = gear
+    param: float
+    steering: Steering
+    gear: Gear
 
     def __repr__(self):
         s = "{ Steering: " + self.steering.name + "\tGear: " + self.gear.name \
@@ -102,16 +103,17 @@ def timeflip(path):
     """
     timeflip transform described around the end of the article
     """
-    new_path = path.copy()
+    new_path = [replace(e) for e in path]
     for e in new_path:
         e.reverse_gear()
     return new_path
 
+
 def reflect(path):
     """
     reflect transform described around the end of the article
     """
-    new_path = path.copy()
+    new_path = [replace(e) for e in path]
     for e in new_path:
         e.reverse_steering()
     return new_path

diff --git a/test_reeds_shepp.py b/test_reeds_shepp.py
@@ -1,5 +1,5 @@
 import unittest
-from reeds_shepp import PathElement, Steering, Gear, path_length
+from reeds_shepp import PathElement, Steering, Gear, path_length, timeflip, reflect
 
 
 class TestPathElement(unittest.TestCase):
@@ -36,5 +36,54 @@ def test_with_positive_path_elements(self):
         )
 
 
+class TestTimeflip(unittest.TestCase):
+    def setUp(self) -> None:
+        self.path = [PathElement(1, Steering.LEFT, g) for g in (Gear.FORWARD, Gear.BACKWARD)]
+        self.timeflipped = timeflip(self.path)
+
+    def test_it_flips_forward_backward(self):
+        self.assertEqual(
+            self.timeflipped[0].gear,
+            Gear.BACKWARD
+        )
+        self.assertEqual(
+            self.timeflipped[1].gear,
+            Gear.FORWARD
+        )
+
+    def test_it_does_not_mutate_original_path(self):
+        self.assertEqual(
+            self.path[0].gear,
+            Gear.FORWARD,
+        )
+
+
+class TestReflect(unittest.TestCase):
+    def setUp(self) -> None:
+        self.path = [PathElement(1, s, Gear.FORWARD) for s in (Steering.LEFT, Steering.STRAIGHT, Steering.RIGHT)]
+        self.reflected = reflect(self.path)
+
+    def test_it_reflects_steering(self):
+        self.assertEqual(
+            self.reflected[0].steering,
+            Steering.RIGHT
+        )
+        self.assertEqual(
+            self.reflected[1].steering,
+            Steering.STRAIGHT
+        )
+        self.assertEqual(
+            self.reflected[2].steering,
+            Steering.LEFT
+        )
+
+    def test_it_does_not_mutate_original_path(self):
+        self.assertEqual(
+            self.path[0].steering,
+            Steering.LEFT,
+        )
+
+
+
 if __name__ == '__main__':
     unittest.main()