Support only new step API (while retaining compatibility functions) (#3019)

tests/vector/test_async_vector_env.py

@@ -68,7 +68,7 @@ def test_step_async_vector_env(shared_memory, use_single_action_space):
         actions = [env.single_action_space.sample() for _ in range(8)]
     else:
         actions = env.action_space.sample()
-    observations, rewards, dones, _ = env.step(actions)
+    observations, rewards, terminateds, truncateds, _ = env.step(actions)
 
     env.close()
 
@@ -83,10 +83,15 @@ def test_step_async_vector_env(shared_memory, use_single_action_space):
     assert rewards.ndim == 1
     assert rewards.size == 8
 
-    assert isinstance(dones, np.ndarray)
-    assert dones.dtype == np.bool_
-    assert dones.ndim == 1
-    assert dones.size == 8
+    assert isinstance(terminateds, np.ndarray)
+    assert terminateds.dtype == np.bool_
+    assert terminateds.ndim == 1
+    assert terminateds.size == 8
+
+    assert isinstance(truncateds, np.ndarray)
+    assert truncateds.dtype == np.bool_
+    assert truncateds.ndim == 1
+    assert truncateds.size == 8
 
 
 @pytest.mark.parametrize("shared_memory", [True, False])
@@ -169,7 +174,7 @@ def test_step_timeout_async_vector_env(shared_memory):
     with pytest.raises(TimeoutError):
         env.reset()
         env.step_async(np.array([0.1, 0.1, 0.3, 0.1]))
-        observations, rewards, dones, _ = env.step_wait(timeout=0.1)
+        observations, rewards, terminateds, truncateds, _ = env.step_wait(timeout=0.1)
     env.close(terminate=True)
 
 
@@ -262,7 +267,7 @@ def test_custom_space_async_vector_env():
     assert isinstance(env.action_space, Tuple)
 
     actions = ("action-2", "action-3", "action-5", "action-7")
-    step_observations, rewards, dones, _ = env.step(actions)
+    step_observations, rewards, terminateds, truncateds, _ = env.step(actions)
 
     env.close()