Add test if type with numpy array serializes back to ndarray

tests/patterns/numpy_type_test.py

@@ -0,0 +1,48 @@
+import asdf
+import numpy as np
+from asdf.extension import Extension
+from numpy.typing import NDArray
+
+from asdf_pydantic import AsdfPydanticConverter, AsdfPydanticModel
+
+
+class ArrayContainer(AsdfPydanticModel):
+    _tag = "asdf://asdf-pydantic/examples/tags/array-container-1.0.0"
+
+    array: NDArray  # Equivalently np.ndarray
+
+
+def setup_module():
+    """Register the ArrayContainer model with the AsdfPydanticConverter.
+
+    Pytest will run this function before the tests in this module.
+    """
+    AsdfPydanticConverter.add_models(ArrayContainer)
+
+    class TestExtension(Extension):
+        extension_uri = "asdf://asdf-pydantic/examples/extensions/test-1.0.0"
+
+        converters = [AsdfPydanticConverter()]  # type: ignore
+        tags = [*AsdfPydanticConverter().tags]  # type: ignore
+
+    asdf.get_config().add_extension(TestExtension())
+
+
+########################################################################################
+# Test Cases
+########################################################################################
+
+
+def test_convert_ArrayContainer_to_asdf(tmp_path):
+    """When writing ArrayContainer to an ASDF file, the array field should be
+    serialized to the original numpy array.
+    """
+    af = asdf.AsdfFile({"data": ArrayContainer(array=np.array([1, 2, 3]))}).write_to(
+        tmp_path / "test.asdf"
+    )
+
+    with asdf.open(tmp_path / "test.asdf") as af:
+        assert isinstance(af.tree["array"], np.ndarray), (
+            f"Expected {type(np.ndarray)}, " f"got {type(af.tree['array'])}"
+        )
+        assert np.all(af.tree["array"] == np.array([1, 2, 3]))