export SimpleEnv and assert_envs_equal, fix minor bug in action space (#46)

baselines/common/vec_env/test_vec_env.py

@@ -10,6 +10,39 @@ from .shmem_vec_env import ShmemVecEnv
 from .subproc_vec_env import SubprocVecEnv
 
 
+def assert_envs_equal(env1, env2, num_steps):
+    """
+    Compare two environments over num_steps steps and make sure
+    that the observations produced by each are the same when given
+    the same actions.
+    """
+    assert env1.num_envs == env2.num_envs
+    assert env1.action_space.shape == env2.action_space.shape
+    assert env1.action_space.dtype == env2.action_space.dtype
+    joint_shape = (env1.num_envs,) + env1.action_space.shape
+
+    try:
+        obs1, obs2 = env1.reset(), env2.reset()
+        assert np.array(obs1).shape == np.array(obs2).shape
+        assert np.array(obs1).shape == joint_shape
+        assert np.allclose(obs1, obs2)
+        np.random.seed(1337)
+        for _ in range(num_steps):
+            actions = np.array(np.random.randint(0, 0x100, size=joint_shape),
+                               dtype=env1.action_space.dtype)
+            for env in [env1, env2]:
+                env.step_async(actions)
+            outs1 = env1.step_wait()
+            outs2 = env2.step_wait()
+            for out1, out2 in zip(outs1[:3], outs2[:3]):
+                assert np.array(out1).shape == np.array(out2).shape
+                assert np.allclose(out1, out2)
+            assert list(outs1[3]) == list(outs2[3])
+    finally:
+        env1.close()
+        env2.close()
+
+
 @pytest.mark.parametrize('klass', (ShmemVecEnv, SubprocVecEnv))
 @pytest.mark.parametrize('dtype', ('uint8', 'float32'))
 def test_vec_env(klass, dtype):  # pylint: disable=R0914
@@ -26,33 +59,14 @@ def test_vec_env(klass, dtype):  # pylint: disable=R0914
         """
         Get an environment constructor with a seed.
         """
-        return lambda: _SimpleEnv(seed, shape, dtype)
+        return lambda: SimpleEnv(seed, shape, dtype)
     fns = [make_fn(i) for i in range(num_envs)]
     env1 = DummyVecEnv(fns)
     env2 = klass(fns)
-    try:
-        obs1, obs2 = env1.reset(), env2.reset()
-        assert np.array(obs1).shape == np.array(obs2).shape
-        assert np.allclose(obs1, obs2)
-        np.random.seed(1337)
-        for _ in range(num_steps):
-            joint_shape = (len(fns),) + shape
-            actions = np.array(np.random.randint(0, 0x100, size=joint_shape),
-                               dtype=dtype)
-            for env in [env1, env2]:
-                env.step_async(actions)
-            outs1 = env1.step_wait()
-            outs2 = env2.step_wait()
-            for out1, out2 in zip(outs1[:3], outs2[:3]):
-                assert np.array(out1).shape == np.array(out2).shape
-                assert np.allclose(out1, out2)
-            assert list(outs1[3]) == list(outs2[3])
-    finally:
-        env1.close()
-        env2.close()
+    assert_envs_equal(env1, env2, num_steps=num_steps)
 
 
-class _SimpleEnv(gym.Env):
+class SimpleEnv(gym.Env):
     """
     An environment with a pre-determined observation space
     and RNG seed.
@@ -66,7 +80,9 @@ class _SimpleEnv(gym.Env):
         self._max_steps = seed + 1
         self._cur_obs = None
         self._cur_step = 0
-        self.action_space = gym.spaces.Box(low=0, high=100, shape=shape, dtype=dtype)
+        # this is 0xFF instead of 0x100 because the Box space includes
+        # the high end, while randint does not
+        self.action_space = gym.spaces.Box(low=0, high=0xFF, shape=shape, dtype=dtype)
         self.observation_space = self.action_space
 
     def step(self, action):