chore: import upstream snapshot with attribution

python/ray/train/v2/tests/test_env_callbacks.py

@@ -0,0 +1,109 @@
+import os
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from ray.train.v2._internal.callbacks.env_callback import _initialize_env_callbacks
+from ray.train.v2._internal.constants import RAY_TRAIN_CALLBACKS_ENV_VAR
+from ray.train.v2._internal.execution.callback import RayTrainCallback
+
+
+class MockCallback(RayTrainCallback):
+    pass
+
+
+@pytest.mark.parametrize(
+    "env_value,expected_callback_count",
+    [
+        ("my.module.Callback1", 1),
+        ("module1.Callback1,module2.Callback2", 2),
+        ("", 0),
+        ("   ", 0),
+        ("module.Callback1, ,module.Callback2", 2),
+    ],
+)
+@patch("importlib.import_module")
+def test_env_callbacks_loading(mock_import, env_value, expected_callback_count):
+    """Test loading execution callbacks from environment variable with various inputs."""
+    if env_value:
+        with patch.dict(os.environ, {RAY_TRAIN_CALLBACKS_ENV_VAR: env_value}):
+
+            mock_module = MagicMock()
+            mock_module.Callback1 = MockCallback
+            mock_module.Callback2 = MockCallback
+            mock_import.return_value = mock_module
+
+            callbacks = _initialize_env_callbacks()
+
+            assert len(callbacks) == expected_callback_count
+            for callback in callbacks:
+                assert isinstance(callback, RayTrainCallback)
+
+    else:
+        with patch.dict(
+            os.environ, {RAY_TRAIN_CALLBACKS_ENV_VAR: env_value}, clear=True
+        ):
+            callbacks = _initialize_env_callbacks()
+            assert len(callbacks) == 0
+
+
+@pytest.mark.parametrize(
+    "env_value,original_error_type",
+    [
+        ("invalid_module", ValueError),
+        ("module.Class", TypeError),
+        ("module.NonExistentClass", AttributeError),
+    ],
+)
+@patch("importlib.import_module")
+def test_callback_loading_errors(mock_import, env_value, original_error_type):
+    """Test handling of various error conditions when loading callbacks."""
+    with patch.dict(os.environ, {RAY_TRAIN_CALLBACKS_ENV_VAR: env_value}):
+        if "invalid_module" in env_value:
+            pass
+        elif "NonExistentClass" in env_value:
+            mock_module = MagicMock()
+            del mock_module.NonExistentClass
+            mock_import.return_value = mock_module
+        else:
+            mock_module = MagicMock()
+
+            class RegularClass:
+                pass
+
+            mock_module.Class = RegularClass
+            mock_import.return_value = mock_module
+
+        with pytest.raises(
+            ValueError, match=f"Failed to import callback from '{env_value}'"
+        ) as exc_info:
+            _initialize_env_callbacks()
+
+        assert isinstance(exc_info.value.__cause__, original_error_type)
+
+
+def test_import_error_handling():
+    """Test handling of import errors when loading callbacks."""
+    with patch.dict(
+        os.environ, {RAY_TRAIN_CALLBACKS_ENV_VAR: "nonexistent.module.TestCallback"}
+    ):
+        with pytest.raises(
+            ValueError,
+            match="Failed to import callback from 'nonexistent.module.TestCallback'",
+        ):
+            _initialize_env_callbacks()
+
+
+def test_no_env_variable():
+    """Test that no callbacks are loaded when environment variable is not set."""
+    if RAY_TRAIN_CALLBACKS_ENV_VAR in os.environ:
+        del os.environ[RAY_TRAIN_CALLBACKS_ENV_VAR]
+
+    callbacks = _initialize_env_callbacks()
+    assert len(callbacks) == 0
+
+
+if __name__ == "__main__":
+    import sys
+
+    sys.exit(pytest.main(["-v", __file__]))