spaces equality fixes and tests (#1375)

* spaces equality fixes and tests

* squash-merged master

* added better equality tests and more checks against bad space creation

gym/spaces/box.py

@@ -57,4 +57,4 @@ class Box(Space):
         return "Box" + str(self.shape)
 
     def __eq__(self, other):
-        return np.allclose(self.low, other.low) and np.allclose(self.high, other.high)
+        return isinstance(other, Box) and np.allclose(self.low, other.low) and np.allclose(self.high, other.high)

gym/spaces/dict_space.py

@@ -36,6 +36,8 @@ class Dict(Space):
         assert (spaces is None) or (not spaces_kwargs), 'Use either Dict(spaces=dict(...)) or Dict(foo=x, bar=z)'
         if spaces is None:
             spaces = spaces_kwargs
+        for space in spaces.values():
+            assert isinstance(space, gym.Space), 'Values of the dict should be instances of gym.Space'
         if isinstance(spaces, dict) and not isinstance(spaces, OrderedDict):
             spaces = OrderedDict(sorted(list(spaces.items())))
         if isinstance(spaces, list):
@@ -80,4 +82,4 @@ class Dict(Space):
         return ret
 
     def __eq__(self, other):
-        return self.spaces == other.spaces
+        return isinstance(other, Dict) and self.spaces == other.spaces

gym/spaces/discrete.py

@@ -34,4 +34,4 @@ class Discrete(Space):
         return "Discrete(%d)" % self.n
 
     def __eq__(self, other):
-        return self.n == other.n
+        return isinstance(other, Discrete) and self.n == other.n

gym/spaces/multi_binary.py

@@ -28,4 +28,4 @@ class MultiBinary(Space):
         return "MultiBinary({})".format(self.n)
 
     def __eq__(self, other):
-        return self.n == other.n
+        return isinstance(other, MultiBinary) and self.n == other.n

gym/spaces/multi_discrete.py

@@ -54,4 +54,4 @@ class MultiDiscrete(Space):
         return "MultiDiscrete({})".format(self.nvec)
 
     def __eq__(self, other):
-        return np.all(self.nvec == other.nvec)
+        return isinstance(other, MultiDiscrete) and np.all(self.nvec == other.nvec)

gym/spaces/tests/test_spaces.py

@@ -84,3 +84,26 @@ def test_sample(space):
     else:
         raise NotImplementedError
     np.testing.assert_allclose(expected_mean, samples.mean(), atol=3.0 * samples.std())
+
+@pytest.mark.parametrize("spaces", [
+    (Discrete(5), MultiBinary(5)),
+    (Box(low=np.array([-10, 0]), high=np.array([10,10]), dtype=np.float32), MultiDiscrete([2, 2, 8])),
+    (Dict({"position": Discrete(5)}), Tuple([Discrete(5)])),
+    (Dict({"position": Discrete(5)}), Discrete(5)),
+    (Tuple((Discrete(5),)), Discrete(5)),
+])
+def test_class_inequality(spaces):
+    assert spaces[0] == spaces[0]
+    assert spaces[1] == spaces[1]
+    assert spaces[0] != spaces[1]
+    assert spaces[1] != spaces[0]
+
+
+@pytest.mark.parametrize("space_fn", [
+    lambda: Dict(space1='abc'),
+    lambda: Dict({'space1': 'abc'}),
+    lambda: Tuple(['abc'])
+])
+def test_bad_space_calls(space_fn):
+    with pytest.raises(AssertionError):
+        space_fn()

gym/spaces/tuple_space.py

@@ -11,6 +11,8 @@ class Tuple(Space):
     """
     def __init__(self, spaces):
         self.spaces = spaces
+        for space in spaces:
+            assert isinstance(space, Space), "Elements of the tuple must be instances of gym.Space"
         super(Tuple, self).__init__(None, None)
 
     def seed(self, seed):
@@ -43,4 +45,4 @@ class Tuple(Space):
         return len(self.spaces)
       
     def __eq__(self, other):
-        return self.spaces == other.spaces
+        return isinstance(other, Tuple) and self.spaces == other.spaces