Check gt4py-backend options in config

ndsl/dsl/stencil_config.py

@@ -6,6 +6,7 @@
 from collections.abc import Callable, Hashable, Iterable, Sequence
 from typing import Any, Self
 
+from gt4py.cartesian.backend import from_name as check_backend_existence
 from gt4py.cartesian.gtc.passes.oir_pipeline import DefaultPipeline, OirPipeline
 
 from ndsl.comm.communicator import Communicator
@@ -43,6 +44,7 @@ def __init__(
         if "gpu" not in backend and device_sync is True:
             raise RuntimeError("Device sync is true on a CPU based backend")
         # GT4Py backend args
+        check_backend_existence(backend)
         self.backend = backend
         self.rebuild = rebuild
         self.validate_args = validate_args

tests/dsl/test_stencil_wrapper.py

@@ -313,24 +313,38 @@ def test_frozen_field_after_parameter() -> None:
     )
 
 
+@pytest.mark.parametrize("backend", ("numpy", "gt:gpu"))
 def test_backend_options(
+    backend: str,
     rebuild: bool = True,
     validate_args: bool = True,
 ) -> None:
-    backend = "numpy"
     expected_options = {
-        "backend": "numpy",
-        "rebuild": True,
-        "format_source": False,
-        "name": "tests.dsl.test_stencil_wrapper.copy_stencil",
+        "numpy": {
+            "backend": "numpy",
+            "rebuild": True,
+            "format_source": False,
+            "name": "tests.dsl.test_stencil_wrapper.copy_stencil",
+        },
+        "gt:gpu": {
+            "backend": "gt:gpu",
+            "rebuild": True,
+            "device_sync": False,
+            "format_source": False,
+            "name": "tests.dsl.test_stencil_wrapper.copy_stencil",
+        },
     }
 
     actual = get_stencil_config(
-        backend=backend,
-        rebuild=rebuild,
-        validate_args=validate_args,
+        backend=backend, rebuild=rebuild, validate_args=validate_args
     ).stencil_kwargs(func=copy_stencil)
-    assert actual == expected_options
+    expected = expected_options[backend]
+    assert actual == expected
+
+
+def test_illegal_backend_options():
+    with pytest.raises(ValueError):
+        get_stencil_config(backend="illegal")
 
 
 def get_mock_quantity():