Merge pull request #11 from thecodingmachine/jindun

handling None type merge
thecodingmachine · Jun 11, 2018 · 9b80009 · 9b80009
2 parents 76dbece + ce6c214
commit 9b80009
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diff --git a/src/tests/tests.py b/src/tests/tests.py
@@ -137,6 +137,9 @@ class TestMergeByType(unittest.TestCase):
     test:
       - item3
     """
+    mock_None = 'test: '
+
+    # from scalar to any 
 
     def test_merge_scalar_to_scalar(self):
         out = yaml_tools.successive_merge([self.mock_scalar_1, self.mock_scalar_2])
@@ -156,6 +159,13 @@ def test_merge_scalar_to_list(self):
         """
         expected_out = ruamel.yaml.round_trip_load(expected_out_str)
         self.assertEqual(out, expected_out)
+
+    def test_merge_scalar_to_None(self):
+        out = yaml_tools.successive_merge([self.mock_None, self.mock_scalar_2])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_scalar_2)
+        self.assertEqual(out, expected_out)
+
+    # from dict to any
 
     def test_merge_dict_to_scalar(self):
         self.assertRaises(TypeError, yaml_tools.successive_merge, [self.mock_scalar_1, self.mock_dict_2])
@@ -173,6 +183,13 @@ def test_merge_dict_to_dict(self):
 
     def test_merge_dict_to_list(self):
         self.assertRaises(TypeError, yaml_tools.successive_merge, [self.mock_list_1, self.mock_dict_2])
+
+    def test_merge_dict_to_None(self):
+        out = yaml_tools.successive_merge([self.mock_None, self.mock_dict_2])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_dict_2)
+        self.assertEqual(out, expected_out)
+
+    ##  from list to any
 
     def test_merge_list_to_scalar(self):
         out = yaml_tools.successive_merge([self.mock_scalar_1, self.mock_list_2])
@@ -198,6 +215,26 @@ def test_merge_list_to_list(self):
         expected_out = ruamel.yaml.round_trip_load(expected_out_str)
         self.assertEqual(out, expected_out)
 
+    def test_merge_list_to_None(self):
+        out = yaml_tools.successive_merge([self.mock_None, self.mock_list_2])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_list_2)
+        self.assertEqual(out, expected_out)
+
+    ##  from None to any
+    def test_merge_None_to_any(self):
+        out = yaml_tools.successive_merge([self.mock_None, self.mock_None])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_None)
+        self.assertEqual(out, expected_out, 'Merge None to None should succeed')
+        out = yaml_tools.successive_merge([self.mock_scalar_1, self.mock_None])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_scalar_1)
+        self.assertEqual(out, expected_out, 'Merge None to scalar should succeed')
+        out = yaml_tools.successive_merge([self.mock_dict_1, self.mock_None])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_dict_1)
+        self.assertEqual(out, expected_out, 'Merge None to dict should succeed')
+        out = yaml_tools.successive_merge([self.mock_list_1, self.mock_None])
+        expected_out = ruamel.yaml.round_trip_load(self.mock_list_1)
+        self.assertEqual(out, expected_out, 'Merge None to list should succeed')
+
 
 if __name__ == '__main__':  # pragma: no cover
     unittest.main()
diff --git a/src/yaml_tools.py b/src/yaml_tools.py
@@ -23,16 +23,22 @@ def _merge(dest, src, current_path=""):
                 if k in src.ca._items and src.ca._items[k][2] and \
                         src.ca._items[k][2].value.strip():
                     dest.ca._items[k] = src.ca._items[k]  # copy non-empty comment
+        elif dest is None:
+            dest = src
         else:
             raise get_type_error(dest, src, current_path)
     elif isinstance(src, ruamel.yaml.comments.CommentedSeq):
         if isinstance(dest, ruamel.yaml.comments.CommentedMap):
             raise get_type_error(dest, src, current_path)
         elif isinstance(dest, ruamel.yaml.comments.CommentedSeq):
             dest.extend(src)
+        elif dest is None:
+            dest=src
         else:
             src.append(dest)
             dest = src
+    elif src is None:
+        return dest
     else:
         if isinstance(dest, ruamel.yaml.comments.CommentedMap):
             raise get_type_error(dest, src, current_path)