Merge pull request #169 from arnauddupuis/arnauddupuis/issue121

[BUG] Actuators needs to return NO_DIR if there is no next_move available.

breaking-changes.txt

@@ -10,11 +10,14 @@ Sprites are not describing the same thing as before.
 
 1.2.0 -> 1.3.0
 
+META: We need some sort of code to show the severity of the breaking change. It should reflect the pain to update.
+
 BoardItem: type in constructor is now item_type. This breaks a lot of things...
 BoardItem: they are now all able to set/get overlappable, restorable, pickable and can_move
 BoardItem: value has been moved to BoardItem.
 BoardItem: change of behavior: now if both model and sprixel are given to the constructor, model is ignored (sprixel has priority). Need an example in the release note.
 BoardItem: there was a conflict with inventory_space. It was defined both as a property and a method. The method has been removed. Concretely: you might have to remove parenthesis when using any_item.inventory_space (vs the old any_item.inventory_space()).
+pygamelib.actuators: all the next_move() methods now returns pygamelib.constants.NO_DIR instead of None if there's no more move to use.
 
 [non breaking][important] Void cells are now initialized with knowing their position.
 [non breaking][important] The observer system has some limitations. One being that notifications are not passed down by attributes.

pygamelib/actuators.py

@@ -156,10 +156,10 @@ def next_move(self):
         """Return a randomly selected movement
 
         The movement is randomly selected from moveset if state is RUNNING,
-        otherwise it should return None.
+        otherwise it returns NO_DIR from the :py:mod:`~pygamelib.constants` module.
 
         :return: The next movement
-        :rtype: int | None
+        :rtype: int | :py:const:`pygamelib.constants.NO_DIR`
 
         Example::
 
@@ -226,12 +226,12 @@ def next_move(self):
         """Return the movement based on current index
 
         The movement is selected from path if state is RUNNING, otherwise
-        it should return None. When state is RUNNING, the movement is selected
-        before incrementing the index by 1. When the index equal the length of
-        path, the index should return back to 0.
+        it returns NO_DIR from the :py:mod:`~pygamelib.constants` module. When state is
+        RUNNING, the movement is selected before incrementing the index by 1. When the
+        index equal the length of path, the index should return back to 0.
 
         :return: The next movement
-        :rtype: int | None
+        :rtype: int | :py:const:`pygamelib.constants.NO_DIR`
 
         Example::
 
@@ -243,6 +243,8 @@ def next_move(self):
             if self.index == len(self.path):
                 self.index = 0
             return move
+        else:
+            return constants.NO_DIR
 
     def set_path(self, path):
         """Defines a new path
@@ -307,14 +309,14 @@ class PatrolActuator(PathActuator):
     def next_move(self):
         """Return the movement based on current index
 
-        The movement is selected from path if state is RUNNING, otherwise it
-        should return None. When state is RUNNING, the movement is selected
-        before incrementing the index by 1. When the index equals the length
-        of path, the index should return back to 0 and the path list should be
-        reversed before the next call.
+        The movement is selected from path if state is RUNNING, otherwise it returns
+        NO_DIR from the :py:mod:`~pygamelib.constants` module. When state is RUNNING,
+        the movement is selected before incrementing the index by 1. When the index
+        equals the length of path, the index should return back to 0 and the path list
+        should be reversed before the next call.
 
         :return: The next movement
-        :rtype: int | None
+        :rtype: int | :py:const:`pygamelib.constants.NO_DIR`
 
         Example::
 
@@ -344,6 +346,8 @@ def next_move(self):
                     elif self.path[i] == constants.DRUP:
                         self.path[i] = constants.DLDOWN
             return move
+        else:
+            return constants.NO_DIR
 
     def serialize(self) -> dict:
         """Return a dictionary with all the attributes of this object.
@@ -398,10 +402,10 @@ def next_move(self):
         """Return the direction.
 
         The movement is always direction if state is RUNNING,
-        otherwise it returns None.
+        otherwise it returns NO_DIR from the :py:mod:`~pygamelib.constants` module.
 
         :return: The next movement
-        :rtype: int | None
+        :rtype: int | :py:const:`pygamelib.constants.NO_DIR`
 
         Example::
 

tests/test_actuators.py

@@ -49,7 +49,7 @@ def test_random_empty(self):
     def test_path(self):
         a = actuators.PathActuator([constants.UP])
         a.pause()
-        self.assertIsNone(a.next_move())
+        self.assertEqual(a.next_move(), constants.NO_DIR)
         a.start()
         self.assertEqual(a.next_move(), constants.UP)
         a.set_path([constants.DOWN])
@@ -69,6 +69,9 @@ def test_patrol(self):
         al = actuators.PatrolActuator.load(data)
         self.assertEqual(al.path, [constants.UP, constants.DOWN])
         self.assertEqual(a.state, al.state)
+        a.pause()
+        self.assertEqual(a.next_move(), constants.NO_DIR)
+        a.start()
         a.next_move()
         self.assertEqual(a.next_move(), constants.DOWN)
         self.assertEqual(a.next_move(), constants.UP)