REF/TST: Add more pytest idiom to resample/test_base.py (pandas-dev#24377)

Author: simonjayhawkins

pandas/tests/resample/conftest.py

@@ -86,10 +86,22 @@ def series(index, _series_name, _static_values):
 
 
 @pytest.fixture
-def frame(index, _static_values):
+def empty_series(series):
+    return series[:0]
+
+
+@pytest.fixture
+def frame(index, _series_name, _static_values):
+    # _series_name is intentionally unused
     return DataFrame({'value': _static_values}, index=index)
 
 
+@pytest.fixture
+def empty_frame(series):
+    index = series.index[:0]
+    return DataFrame(index=index)
+
+
 @pytest.fixture(params=[Series, DataFrame])
 def series_and_frame(request, series, frame):
     if request.param == Series: