[core] add is_sdk_model check and tests (Azure#41445)

Author: iscai-msft

sdk/core/azure-core/CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Features Added
 
 - Added a `start_time` keyword argument to the `start_span` and `start_as_current_span` methods in the `OpenTelemetryTracer` class. This allows users to specify a custom start time for created spans. #41106
+- Added `is_generated_model` method to `azure.core.serialization`. Returns whether a given input is a model from one of our generated sdks. #41445
 
 ### Breaking Changes
 

sdk/core/azure-core/azure/core/serialization.py

@@ -129,3 +129,14 @@ def default(self, o: Any) -> Any:
         except AttributeError:
             pass
         return super(AzureJSONEncoder, self).default(o)
+
+
+def is_generated_model(obj: Any) -> bool:
+    """Check if the object is a generated SDK model.
+
+    :param obj: The object to check.
+    :type obj: any
+    :return: True if the object is a generated SDK model, False otherwise.
+    :rtype: bool
+    """
+    return bool(getattr(obj, "_is_model", False) or hasattr(obj, "_attribute_map"))

sdk/core/azure-core/tests/test_serialization.py

@@ -8,7 +8,7 @@
 import json
 import sys
 
-from azure.core.serialization import AzureJSONEncoder, NULL
+from azure.core.serialization import AzureJSONEncoder, NULL, is_generated_model
 import pytest
 from modeltest._utils.model_base import Model as HybridModel, rest_field
 from modeltest import models
@@ -512,3 +512,45 @@ def test_readonly():
     assert model.id == 1
     assert model.as_dict() == {"id": 1}
     assert model.as_dict(exclude_readonly=True) == {}
+
+
+def test_is_generated_model_with_hybrid_model():
+    assert is_generated_model(HybridModel())
+    assert is_generated_model(models.FlattenModel({"name": "wall-e", "properties": {"description": "a dog", "age": 2}}))
+    assert is_generated_model(models.ClientNamedPropertyModel(prop_client_name="wall-e"))
+    assert is_generated_model(models.ReadonlyModel())
+
+
+def test_is_generated_model_with_msrest_model():
+    # Instead of importing msrest, we're just going to do a basic rendering of the msrest models
+    class MsrestModel(object):
+        _subtype_map = {}
+        _attribute_map = {}
+        _validation = {}
+
+        def __init__(self, *args, **kwargs):
+            self.additional_properties = {}
+
+    assert is_generated_model(MsrestModel())
+
+    class InstantiatedMsrestModel(MsrestModel):
+        def __init__(self, *args, **kwargs):
+            super().__init__(*args, **kwargs)
+            self.attr = "value"
+
+    assert is_generated_model(InstantiatedMsrestModel())
+
+
+def test_is_generated_model_with_non_models():
+    assert not is_generated_model({})
+    assert not is_generated_model([])
+    assert not is_generated_model("string")
+    assert not is_generated_model(42)
+    assert not is_generated_model(None)
+    assert not is_generated_model(object)
+
+    class Model:
+        def __init__(self):
+            self.attr = "value"
+
+    assert not is_generated_model(Model())