Various 'empty' cell-method testcases: failing.

lib/iris/tests/unit/fileformats/netcdf/test_parse_cell_methods.py

@@ -17,18 +17,21 @@
 
 
 class TestParseCellMethods:
- def _check_answers(self, test_strings, result):
+ def _check_answers(self, test_string_or_strings, result):
  """
  Compare a list of test strings against a single expected result.
 
  Done this way so that any failures produce intelligible Pytest messages.
  """
+ if isinstance(test_string_or_strings, str):
+ test_string_or_strings = [test_string_or_strings]
  expected_tests_and_results = [
- (cell_method_str, result) for cell_method_str in test_strings
+ (cell_method_str, result)
+ for cell_method_str in test_string_or_strings
  ]
  actual_tests_and_results = [
  (cell_method_str, parse_cell_methods(cell_method_str))
- for cell_method_str in test_strings
+ for cell_method_str in test_string_or_strings
  ]
  assert actual_tests_and_results == expected_tests_and_results
 
@@ -146,7 +149,7 @@ def test_comment_bracket_mismatch_warning(self):
  with pytest.warns(UserWarning, match=msg):
  self._check_answers(cell_method_strings, expected)
 
- def test_badly_formatted_warning(self):
+ def test_badly_formatted__warns(self):
  cell_method_strings = [
  (
  "time: (interval: 1 hr comment: first bit) "
@@ -187,7 +190,7 @@ def test_climatology(self):
  )
  self._check_answers(cell_method_strings, expected)
 
- def test_climatology_with_unknown_method(self):
+ def test_climatology_with_unknown_method__warns(self):
  cell_method_strings = [
  "time: min within days time: mean over days",
  "time : min within days time: mean over days",
@@ -203,3 +206,38 @@ def test_climatology_with_unknown_method(self):
  with pytest.warns(UnknownCellMethodWarning, match=msg):
  res = parse_cell_methods(cell_method_str)
  assert res == expected
+
+ def test_empty__warns(self):
+ cm_str = ""
+ msg = "contains no valid cell methods"
+ with pytest.warns(UserWarning, match=msg):
+ result = parse_cell_methods(cm_str)
+ assert result == ()
+
+ def test_whitespace__warns(self):
+ cm_str = " \t "
+ msg = "contains no valid cell methods"
+ with pytest.warns(UserWarning, match=msg):
+ result = parse_cell_methods(cm_str)
+ assert result == ()
+
+ def test_barename__warns(self):
+ cm_str = "time"
+ msg = "contains no valid cell methods"
+ with pytest.warns(UserWarning, match=msg):
+ result = parse_cell_methods(cm_str)
+ assert result == ()
+
+ def test_missedspace__warns(self):
+ cm_str = "time:mean"
+ msg = "contains no valid cell methods"
+ with pytest.warns(UserWarning, match=msg):
+ result = parse_cell_methods(cm_str)
+ assert result == ()
+
+ def test_random_junk__warns(self):
+ cm_str = "y:12+4#?x:this"
+ msg = "contains no valid cell methods"
+ with pytest.warns(UserWarning, match=msg):
+ result = parse_cell_methods(cm_str)
+ assert result == ()