Added exception handling to the model

Author: rofrano

service/models.py

@@ -85,8 +85,13 @@ def create(self):
         logger.info("Creating %s", self.name)
         # id must be none to generate next primary key
         self.id = None  # pylint: disable=invalid-name
-        db.session.add(self)
-        db.session.commit()
+        try:
+            db.session.add(self)
+            db.session.commit()
+        except Exception as e:
+            db.session.rollback()
+            logger.error("Error creating record: %s", self)
+            raise DataValidationError(e) from e
 
     def update(self):
         """
@@ -95,13 +100,23 @@ def update(self):
         logger.info("Saving %s", self.name)
         if not self.id:
             raise DataValidationError("Update called with empty ID field")
-        db.session.commit()
+        try:
+            db.session.commit()
+        except Exception as e:
+            db.session.rollback()
+            logger.error("Error updating record: %s", self)
+            raise DataValidationError(e) from e
 
     def delete(self):
         """Removes a Pet from the data store"""
         logger.info("Deleting %s", self.name)
-        db.session.delete(self)
-        db.session.commit()
+        try:
+            db.session.delete(self)
+            db.session.commit()
+        except Exception as e:
+            db.session.rollback()
+            logger.error("Error deleting record: %s", self)
+            raise DataValidationError(e) from e
 
     def serialize(self) -> dict:
         """Serializes a Pet into a dictionary"""
@@ -111,7 +126,7 @@ def serialize(self) -> dict:
             "category": self.category,
             "available": self.available,
             "gender": self.gender.name,  # convert enum to string
-            "birthday": self.birthday.isoformat()
+            "birthday": self.birthday.isoformat(),
         }
 
     def deserialize(self, data: dict):
@@ -135,7 +150,9 @@ def deserialize(self, data: dict):
         except AttributeError as error:
             raise DataValidationError("Invalid attribute: " + error.args[0]) from error
         except KeyError as error:
-            raise DataValidationError("Invalid pet: missing " + error.args[0]) from error
+            raise DataValidationError(
+                "Invalid pet: missing " + error.args[0]
+            ) from error
         except TypeError as error:
             raise DataValidationError(
                 "Invalid pet: body of request contained bad or no data " + str(error)

tests/test_models.py

@@ -18,6 +18,7 @@
 import os
 import logging
 from unittest import TestCase
+from unittest.mock import patch
 from datetime import date
 from wsgi import app
 from service.models import Pet, Gender, DataValidationError, db
@@ -218,6 +219,34 @@ def test_deserialize_bad_gender(self):
         self.assertRaises(DataValidationError, pet.deserialize, data)
 
 
+######################################################################
+#  T E S T   E X C E P T I O N   H A N D L E R S
+######################################################################
+class TestExceptionHandlers(TestCaseBase):
+    """Pet Model Exception Handlers"""
+
+    @patch("service.models.db.session.commit")
+    def test_create_exception(self, exception_mock):
+        """It should catch a create exception"""
+        exception_mock.side_effect = Exception()
+        pet = PetFactory()
+        self.assertRaises(DataValidationError, pet.create)
+
+    @patch("service.models.db.session.commit")
+    def test_update_exception(self, exception_mock):
+        """It should catch a update exception"""
+        exception_mock.side_effect = Exception()
+        pet = PetFactory()
+        self.assertRaises(DataValidationError, pet.update)
+
+    @patch("service.models.db.session.commit")
+    def test_delete_exception(self, exception_mock):
+        """It should catch a delete exception"""
+        exception_mock.side_effect = Exception()
+        pet = PetFactory()
+        self.assertRaises(DataValidationError, pet.delete)
+
+
 ######################################################################
 #  Q U E R Y   T E S T   C A S E S
 ######################################################################

tests/test_routes.py

@@ -23,6 +23,7 @@
 # from unittest.mock import MagicMock, patch
 from urllib.parse import quote_plus
 from wsgi import app
+
 # from service import create_app
 from service.common import status
 from service.models import Pet, db
@@ -79,7 +80,9 @@ def _create_pets(self, count):
             test_pet = PetFactory()
             response = self.client.post(BASE_URL, json=test_pet.serialize())
             self.assertEqual(
-                response.status_code, status.HTTP_201_CREATED, "Could not create test pet"
+                response.status_code,
+                status.HTTP_201_CREATED,
+                "Could not create test pet",
             )
             new_pet = response.get_json()
             test_pet.id = new_pet["id"]
@@ -189,8 +192,7 @@ def test_query_pet_list_by_category(self):
         test_category = pets[0].category
         category_pets = [pet for pet in pets if pet.category == test_category]
         response = self.client.get(
-            BASE_URL,
-            query_string=f"category={quote_plus(test_category)}"
+            BASE_URL, query_string=f"category={quote_plus(test_category)}"
         )
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         data = response.get_json()
@@ -200,9 +202,46 @@ def test_query_pet_list_by_category(self):
             self.assertEqual(pet["category"], test_category)
 
     ######################################################################
-    #  T E S T   S A D   P A T H S
+    #  T E S T   A C T I O N S
     ######################################################################
 
+    def test_purchase_a_pet(self):
+        """It should Purchase a Pet"""
+        pets = self._create_pets(10)
+        available_pets = [pet for pet in pets if pet.available is True]
+        pet = available_pets[0]
+        response = self.client.put(f"{BASE_URL}/{pet.id}/purchase")
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        response = self.client.get(f"{BASE_URL}/{pet.id}")
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        data = response.get_json()
+        logging.debug("Response data: %s", data)
+        self.assertEqual(data["available"], False)
+
+    def test_purchase_not_available(self):
+        """It should not Purchase a Pet that is not available"""
+        pets = self._create_pets(10)
+        unavailable_pets = [pet for pet in pets if pet.available is False]
+        pet = unavailable_pets[0]
+        response = self.client.put(f"{BASE_URL}/{pet.id}/purchase")
+        self.assertEqual(response.status_code, status.HTTP_409_CONFLICT)
+
+
+######################################################################
+#  T E S T   S A D   P A T H S
+######################################################################
+class TestSadPaths(TestCase):
+    """Test REST Exception Handling"""
+
+    def setUp(self):
+        """Runs before each test"""
+        self.client = app.test_client()
+
+    def test_method_not_allowed(self):
+        """It should not allow update without a pet id"""
+        response = self.client.put(BASE_URL)
+        self.assertEqual(response.status_code, status.HTTP_405_METHOD_NOT_ALLOWED)
+
     def test_create_pet_no_data(self):
         """It should not Create a Pet with missing data"""
         response = self.client.post(BASE_URL, json={})
@@ -233,35 +272,10 @@ def test_create_pet_bad_gender(self):
         logging.debug(pet)
         # change gender to a bad string
         test_pet = pet.serialize()
-        test_pet["gender"] = "male"    # wrong case
+        test_pet["gender"] = "male"  # wrong case
         response = self.client.post(BASE_URL, json=test_pet)
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
 
-    ######################################################################
-    #  T E S T   A C T I O N S
-    ######################################################################
-
-    def test_purchase_a_pet(self):
-        """It should Purchase a Pet"""
-        pets = self._create_pets(10)
-        available_pets = [pet for pet in pets if pet.available is True]
-        pet = available_pets[0]
-        response = self.client.put(f"{BASE_URL}/{pet.id}/purchase")
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-        response = self.client.get(f"{BASE_URL}/{pet.id}")
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-        data = response.get_json()
-        logging.debug("Response data: %s", data)
-        self.assertEqual(data["available"], False)
-
-    def test_purchase_not_available(self):
-        """It should not Purchase a Pet that is not available"""
-        pets = self._create_pets(10)
-        unavailable_pets = [pet for pet in pets if pet.available is False]
-        pet = unavailable_pets[0]
-        response = self.client.put(f"{BASE_URL}/{pet.id}/purchase")
-        self.assertEqual(response.status_code, status.HTTP_409_CONFLICT)
-
     ######################################################################
     #  T E S T   M O C K S
     ######################################################################