Add __repr__ for DNode objects. (#245)

CHANGES.rst

@@ -22,6 +22,8 @@
 
 - Include tests in coverage and turn testing warnings into errors. [#238]
 
+- Add ``__repr__`` to ``DNode``. [#245]
+
 0.16.1 (2023-06-27)
 ===================
 

src/roman_datamodels/stnode/_node.py

@@ -221,6 +221,9 @@ def __delitem__(self, key):
     def __iter__(self):
         return iter(self._data)
 
+    def __repr__(self):
+        return repr(self._data)
+
     def copy(self):
         instance = self.__class__.__new__(self.__class__)
         instance.__dict__.update(self.__dict__.copy())

tests/test_stnode.py

@@ -303,3 +303,24 @@ def test_will_strict_validate(env_strict_var):
     del os.environ[validate.ROMAN_STRICT_VALIDATION]
     assert os.getenv(validate.ROMAN_STRICT_VALIDATION) is None
     assert validate.will_strict_validate() is True
+
+
+@pytest.mark.parametrize("model", [mdl for mdl in datamodels.MODEL_REGISTRY.values() if "Ref" not in mdl.__name__])
+def test_node_representation(model):
+    """
+    Regression test for #244.
+
+    The DNode object was lacking the __repr__ method, which is used to return
+    the representation of the object. The reported issue was with ``mdl.meta.instrument``,
+    so that is directly checked here.
+    """
+    mdl = maker_utils.mk_datamodel(model)
+
+    if hasattr(mdl, "meta"):
+        assert repr(mdl.meta.instrument) == repr(
+            {
+                "name": "WFI",
+                "detector": "WFI01",
+                "optical_element": "F158",
+            }
+        )