chore: import upstream snapshot with attribution

rllib/utils/tests/test_errors.py

@@ -0,0 +1,89 @@
+import unittest
+
+import gymnasium as gym
+
+import ray
+import ray.rllib.algorithms.impala as impala
+import ray.rllib.algorithms.ppo as ppo
+
+
+class TestErrors(unittest.TestCase):
+    """Tests various failure-modes, making sure we produce meaningful errmsgs."""
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        ray.init()
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        ray.shutdown()
+
+    def test_no_gpus_error(self):
+        """Tests errors related to no-GPU/too-few GPUs/etc.
+
+        This test will only work ok on a CPU-only machine.
+        """
+
+        config = (
+            impala.IMPALAConfig()
+            .api_stack(
+                enable_rl_module_and_learner=False,
+                enable_env_runner_and_connector_v2=False,
+            )
+            .environment("CartPole-v1")
+        )
+
+        self.assertRaisesRegex(
+            RuntimeError,
+            # (?s): "dot matches all" (also newlines).
+            "(?s)Found 0 GPUs on your machine.+To change the config",
+            lambda: config.build(),
+        )
+
+    def test_bad_envs(self):
+        """Tests different "bad env" errors."""
+        config = (
+            ppo.PPOConfig().env_runners(num_env_runners=0)
+            # Non existing/non-registered gym env string.
+            .environment("Alien-Attack-v42")
+        )
+
+        self.assertRaisesRegex(
+            gym.error.NameNotFound,
+            "doesn't exist",
+            lambda: config.build(),
+        )
+
+        # Malformed gym env string (must have v\d at end).
+        config.environment("Alien-Attack-part-42")
+        self.assertRaisesRegex(
+            gym.error.NameNotFound,
+            "doesn't exist",
+            lambda: config.build(),
+        )
+
+        # Non-existing class in a full-class-path.
+        config.environment(
+            "ray.rllib.examples.envs.classes.random_env.RandomEnvThatDoesntExist"
+        )
+        self.assertRaisesRegex(
+            gym.error.NameNotFound,
+            "doesn't exist",
+            lambda: config.build(),
+        )
+
+        # Non-existing module inside a full-class-path.
+        config.environment("ray.rllib.examples.envs.module_that_doesnt_exist.SomeEnv")
+        self.assertRaisesRegex(
+            gym.error.NameNotFound,
+            "doesn't exist",
+            lambda: config.build(),
+        )
+
+
+if __name__ == "__main__":
+    import sys
+
+    import pytest
+
+    sys.exit(pytest.main(["-v", __file__]))