test: Add tests for finding end date

test_ADASMELIAE.py

 import pytest
-from datetime import datetime
-from ADASMELIAE import find_start_date
+from datetime import datetime, timedelta
+from ADASMELIAE import find_start_date, find_end_date
 
 
 @pytest.fixture
 def example_result_files():
+    # Fixture for generating content of result dir
     return [
         "result_2023-04-15.nc",
         "result_2023-04-16.nc",
@@ -16,6 +17,12 @@ def example_result_files():
     ]
 
 
+@pytest.fixture
+def today():
+    # Fixture for generating date for testing
+    return datetime.now().date()
+
+
 def test_find_start_date_with_previous_results(example_result_files, monkeypatch):
     MODEL_START_DATE = datetime(2023, 3, 1)
     monkeypatch.setenv("DATA_DIR", "out")
@@ -41,3 +48,20 @@ def test_find_start_date_without_previous_results(monkeypatch):
 
     # Assert the expected start date
     assert start_date == MODEL_START_DATE
+
+
+def test_find_end_date_when_model_end_date_is_in_past(today):
+    # Test when model end date is in the past
+    model_end_date = datetime.now().date() - timedelta(days=1)
+    assert find_end_date(model_end_date=model_end_date) == model_end_date
+
+
+def test_find_end_date_when_model_end_date_is_in_future(today):
+    # Test when model end date is in the future
+    model_end_date = datetime.now().date() + timedelta(days=1)
+    assert find_end_date(model_end_date=model_end_date) == today
+
+
+def test_find_end_date_equal(today):
+    # Test when model end date is today
+    assert find_end_date(model_end_date=today) == today