when calling Datamodel.validate use a schema if available (#140)

* add test for validate when datamodel modified as dict

adds a minimal case for RCAL-538

* have validate use a schema if available

fixes RCAL-538

CHANGES.rst

@@ -12,6 +12,8 @@
 
 - update minimum version of ``numpy`` to ``1.20`` and add minimum dependency testing to CI [#114]
 
+- Use available tag schema if available during datamodels.validate [#140]
+
 0.14.1 (2023-01-31)
 ===================
 

src/roman_datamodels/validate.py

@@ -33,7 +33,7 @@ def value_change(value, pass_invalid_values, strict_validation):
         if pass_invalid_values:
             update = True
         if strict_validation:
-            raise jsonschema.ValidationError(errmsg)
+            raise errmsg
         else:
             warnings.warn(errmsg, ValidationWarning)
     return update
@@ -61,7 +61,10 @@ def _check_value(value):
 
     validator_context = AsdfFile()
 
-    temp_schema = {"$schema": "http://stsci.edu/schemas/asdf-schema/0.1.0/asdf-schema"}
+    if hasattr(value, "_schema"):
+        temp_schema = value._schema()
+    else:
+        temp_schema = {"$schema": "http://stsci.edu/schemas/asdf-schema/0.1.0/asdf-schema"}
     validator = asdf_schema.get_validator(temp_schema, validator_context, validators=validator_callbacks)
 
     value = yamlutil.custom_tree_to_tagged_tree(value, validator_context)

tests/test_models.py

@@ -750,3 +750,17 @@ def test_crds_parameters(tmp_path):
 
     crds_pars = ramp.get_crds_parameters()
     assert "roman.meta.exposure.start_time" in crds_pars
+
+
+def test_model_validate_without_save():
+    # regression test for rcal-538
+    img = utils.mk_level1_science_raw()
+    m = datamodels.ImageModel(img)
+
+    # invalidate pointing without using the
+    # data model/node api to avoid a validation
+    # failure here
+    m.meta["pointing"] = {}
+
+    with pytest.raises(ValidationError):
+        m.validate()