Refactor opportunity_to_dict tests for dynamic import

Refactor tests to import opportunity_to_dict dynamically and use a fake Opportunities class.

Author: jaswanthDuddu

tests/test_single_opportunity_routes.py

@@ -1,17 +1,17 @@
 import pytest
 
-from labconnect import db
-from labconnect.main.opportunity_routes import opportunity_to_dict
-from labconnect.models import Opportunities
-
-
 def test_opportunity_to_dict_none():
-    assert opportunity_to_dict(None) == {}
+    from importlib import import_module
+    opp_mod = import_module("labconnect.main.opportunity_routes")
+    assert opp_mod.opportunity_to_dict(None) == {}
 
 
 def test_opportunity_to_dict_populated():
     # create a lightweight Opportunities instance (no DB persistence needed)
-    opp = Opportunities()
+    import
+    class FakeOpp:
+        pass
+    opp = FakeOpp()
     opp.id = 123
     opp.name = "Unit Test Opportunity"
     opp.description = "A test description"
@@ -25,7 +25,9 @@ def test_opportunity_to_dict_populated():
     opp.year = 2025
     opp.active = True
 
-    out = opportunity_to_dict(opp)
+    from importlib import import_module
+    opp_mod = import_module("labconnect.main.opportunity_routes")
+    out = opp_mod.opportunity_to_dict(opp)
 
     assert out["id"] == 123
     assert out["name"] == "Unit Test Opportunity"
@@ -45,6 +47,9 @@ def test_get_single_opportunity_not_found(test_client):
 @pytest.mark.usefixtures("test_client")
 def test_get_single_opportunity_success_and_json_variant(test_client):
     # create and persist an opportunity to the test database
+    from labconnect import db
+    from labconnect.models import Opportunities
+    
     opp = Opportunities()
     opp.name = "Endpoint Test Opportunity"
     opp.description = "Endpoint description"