add tests for input handling

tests/tests_unit/test_input_handling.py

@@ -125,3 +125,43 @@ def test_handle_input_rates_start_and_end_date_equal_works_fine():
 
     for key in expected_result.keys():
         assert handled_inputs[key] == expected_result[key]
+
+
+def test_handle_input_rates_with_pairs_works_fine():
+    handled_inputs = handle_get_rates_inputs(
+        start_date=datetime.datetime.now(),
+        end_date=datetime.datetime.now(),
+        pairs="USDEUR,EURUSD,GBPZAR",
+        dry_run=False,
+        rates_source="mock",
+        ignore_warnings=True,
+        output="test_output.csv",
+    )
+    expected_result = {
+        "date_range": DateRange(
+            start_date=datetime.datetime.now().date(),
+            end_date=datetime.datetime.now().date(),
+        ),
+        "pairs": {"Pending real object"},
+        "dry_run": False,
+        "rates_source": "mock",
+        "ignore_warnings": True,
+        "output": pathlib.Path("test_output.csv"),
+    }
+
+    for key in expected_result.keys():
+        assert handled_inputs[key] == expected_result[key]
+
+
+def test_handle_input_rates_raises_with_both_currencies_and_pairs():
+    with pytest.raises(ValueError):
+        handle_get_rates_inputs(
+            start_date=datetime.datetime.now(),
+            end_date=datetime.datetime.now(),
+            currencies="EUR,USD,ZAR",
+            pairs="USDEUR,EURUSD,GBPZAR",
+            dry_run=False,
+            rates_source="mock",
+            ignore_warnings=True,
+            output="test_output.csv",
+        )