Add comprehensive tests for Parks API and models

- Implemented extensive test cases for the Parks API, covering endpoints for listing, retrieving, creating, updating, and deleting parks.
- Added tests for filtering, searching, and ordering parks in the API.
- Created tests for error handling in the API, including malformed JSON and unsupported methods.
- Developed model tests for Park, ParkArea, Company, and ParkReview models, ensuring validation and constraints are enforced.
- Introduced utility mixins for API and model testing to streamline assertions and enhance test readability.
- Included integration tests to validate complete workflows involving park creation, retrieval, updating, and deletion.

location/models.py

@@ -73,6 +73,27 @@ class Location(TrackedModel):
             models.Index(fields=['country']),
         ]
         ordering = ['name']
+        constraints = [
+            # Business rule: Latitude must be within valid range (-90 to 90)
+            models.CheckConstraint(
+                name="location_latitude_range",
+                check=models.Q(latitude__isnull=True) | (models.Q(latitude__gte=-90) & models.Q(latitude__lte=90)),
+                violation_error_message="Latitude must be between -90 and 90 degrees"
+            ),
+            # Business rule: Longitude must be within valid range (-180 to 180)
+            models.CheckConstraint(
+                name="location_longitude_range",
+                check=models.Q(longitude__isnull=True) | (models.Q(longitude__gte=-180) & models.Q(longitude__lte=180)),
+                violation_error_message="Longitude must be between -180 and 180 degrees"
+            ),
+            # Business rule: If coordinates are provided, both lat and lng must be present
+            models.CheckConstraint(
+                name="location_coordinates_complete",
+                check=models.Q(latitude__isnull=True, longitude__isnull=True) | 
+                      models.Q(latitude__isnull=False, longitude__isnull=False),
+                violation_error_message="Both latitude and longitude must be provided together"
+            ),
+        ]
 
     def __str__(self):
         location_parts = []