Merge pull request #2 from esc24/invalidunits_test

unit test for invalid units handling in _make_cube

lib/iris/tests/unit/fileformats/rules/test__make_cube.py

@@ -0,0 +1,67 @@
+# (C) British Crown Copyright 2014, Met Office
+#
+# This file is part of Iris.
+#
+# Iris is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Iris is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Iris.  If not, see <http://www.gnu.org/licenses/>.
+"""Unit tests for :func:`iris.fileformats.rules._make_cube`."""
+
+# Import iris.tests first so that some things can be initialised before
+# importing anything else.
+import iris.tests as tests
+
+import mock
+
+from iris.fileformats.rules import _make_cube
+
+
+class Test(tests.IrisTest):
+    def test_invalid_units(self):
+        # Mock converter() function that returns an invalid
+        # units string amongst the collection of other elements.
+        factories = None
+        references = None
+        standard_name = None
+        long_name = None
+        units = 'wibble'  # Invalid unit.
+        attributes = dict(source='test')
+        cell_methods = None
+        dim_coords_and_dims = None
+        aux_coords_and_dims = None
+        converter = mock.Mock(return_value=(factories,
+                                            references,
+                                            standard_name,
+                                            long_name,
+                                            units,
+                                            attributes,
+                                            cell_methods,
+                                            dim_coords_and_dims,
+                                            aux_coords_and_dims))
+
+        field = mock.Mock()
+        with mock.patch('warnings.warn') as warn:
+            cube, factories, references = _make_cube(field, converter)
+
+        # Check attributes dictionary is correctly populated.
+        expected_attributes = attributes.copy()
+        expected_attributes['invalid_units'] = units
+        self.assertEqual(cube.attributes, expected_attributes)
+
+        # Check warning was raised.
+        self.assertEqual(warn.call_count, 1)
+        warning_msg = warn.call_args[0][0]
+        self.assertIn('invalid units', warning_msg)
+
+
+if __name__ == "__main__":
+    tests.main()