Merge "layering: Support layering for primitive types"

deckhand/engine/layering.py

@@ -551,6 +551,13 @@ class DocumentLayering(object):
         overall_data = copy.deepcopy(overall_data)
         child_data = copy.deepcopy(child_data)
 
+        # If None is used, then consider it as a placeholder and coerce the
+        # data into a dictionary.
+        if overall_data is None:
+            overall_data = {}
+        if child_data is None:
+            child_data = {}
+
         action_path = action['path']
         if action_path.startswith('.data'):
             action_path = action_path[5:]
@@ -574,7 +581,7 @@ class DocumentLayering(object):
                 engine_utils.deep_delete(from_child, overall_data.data, None)
 
         elif method == self._MERGE_ACTION:
-            from_parent = utils.jsonpath_parse(overall_data.data, action_path)
+            from_overall = utils.jsonpath_parse(overall_data.data, action_path)
             from_child = utils.jsonpath_parse(child_data.data, action_path)
 
             if from_child is None:
@@ -587,13 +594,29 @@ class DocumentLayering(object):
                     parent_name=overall_data.name,
                     action=action)
 
-            if (isinstance(from_parent, dict) and
-                    isinstance(from_child, dict)):
-                engine_utils.deep_merge(from_parent, from_child)
+            # If both the child and parent data are dictionaries, then
+            # traditional merging is possible using JSON path resolution.
+            # Otherwise, JSON path resolution is not possible, so the only
+            # way to perform layering is to prioritize the child data over
+            # that of the parent. This applies when the child data is a
+            # non-dict, the parent data is a non-dict, or both.
+            if all(isinstance(x, dict) for x in (from_overall, from_child)):
+                engine_utils.deep_merge(from_overall, from_child)
+            else:
+                LOG.info('Child data is type: %s for [%s, %s] %s. Parent data '
+                         'is type: %s for [%s, %s] %s. Both must be '
+                         'dictionaries for regular JSON path merging to work. '
+                         'Because this is not the case, child data will be '
+                         'prioritized over parent data for "merge" action.',
+                         type(from_child), child_data.schema, child_data.layer,
+                         child_data.name, type(from_overall),
+                         overall_data.schema, overall_data.layer,
+                         overall_data.name)
+                from_overall = from_child
 
-            if from_parent is not None:
+            if from_overall is not None:
                 overall_data.data = utils.jsonpath_replace(
-                    overall_data.data, from_parent, action_path)
+                    overall_data.data, from_overall, action_path)
             else:
                 overall_data.data = utils.jsonpath_replace(
                     overall_data.data, from_child, action_path)

deckhand/tests/unit/engine/test_document_layering.py

@@ -610,6 +610,58 @@ class TestDocumentLayering2Layers(TestDocumentLayering):
             documents = doc_factory.gen_test(mapping, site_abstract=False)
             self._test_layering(documents, site_expected[idx])
 
+    def test_layering_with_primitives(self):
+        """Validates that layering works with non-dictionaries or "primitives"
+        for short, which include integers, strings, etc.
+        """
+        # Validate layering with strings.
+        mapping = {
+            "_GLOBAL_DATA_1_": {"data": "global"},
+            "_SITE_DATA_1_": {"data": "site"},
+            "_SITE_ACTIONS_1_": {
+                "actions": [{"method": "merge", "path": "."}]}
+        }
+        doc_factory = factories.DocumentFactory(2, [1, 1])
+        documents = doc_factory.gen_test(mapping, site_abstract=False)
+        self._test_layering(documents, site_expected="site")
+
+        # Validate layering with integers.
+        mapping = {
+            "_GLOBAL_DATA_1_": {"data": 2},
+            "_SITE_DATA_1_": {"data": 1},
+            "_SITE_ACTIONS_1_": {
+                "actions": [{"method": "merge", "path": "."}]}
+        }
+        doc_factory = factories.DocumentFactory(2, [1, 1])
+        documents = doc_factory.gen_test(mapping, site_abstract=False)
+        self._test_layering(documents, site_expected=1)
+
+        # Validate layering with mixed primitives.
+        mapping = {
+            "_GLOBAL_DATA_1_": {"data": False},
+            "_SITE_DATA_1_": {"data": 'a'},
+            "_SITE_ACTIONS_1_": {
+                "actions": [{"method": "merge", "path": "."}]}
+        }
+        doc_factory = factories.DocumentFactory(2, [1, 1])
+        documents = doc_factory.gen_test(mapping, site_abstract=False)
+        self._test_layering(documents, site_expected='a')
+
+    def test_layering_with_incompatible_types(self):
+        """Validates that layering works for incompatible types: that is,
+        merging a dictionary with a primitive is not possible. For this
+        case, the child data is simply selected over the parent data.
+        """
+        mapping = {
+            "_GLOBAL_DATA_1_": {"data": {"foo": "bar"}},
+            "_SITE_DATA_1_": {"data": "site"},
+            "_SITE_ACTIONS_1_": {
+                "actions": [{"method": "merge", "path": "."}]}
+        }
+        doc_factory = factories.DocumentFactory(2, [1, 1])
+        documents = doc_factory.gen_test(mapping, site_abstract=False)
+        self._test_layering(documents, site_expected="site")
+
 
 class TestDocumentLayering2LayersAbstractConcrete(TestDocumentLayering):
     """The the 2-layer payload with site/global layers concrete.

deckhand/tests/unit/engine/test_document_layering_and_substitution.py

@@ -219,7 +219,7 @@ class TestDocumentLayeringWithSubstitution(
                     "path": "."
                 }
             }],
-            "_SITE_DATA_1_": {"data": "placeholder"},
+            "_SITE_DATA_1_": {"data": {}},
             "_SITE_ACTIONS_1_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_1_": [{
@@ -275,7 +275,7 @@ class TestDocumentLayeringWithSubstitution(
                     "path": "."
                 }
             }],
-            "_SITE_DATA_1_": {"data": "placeholder"},
+            "_SITE_DATA_1_": {"data": {}},
             "_SITE_ACTIONS_1_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_1_": [{
@@ -288,7 +288,7 @@ class TestDocumentLayeringWithSubstitution(
                     "path": "."
                 }
             }],
-            "_SITE_DATA_2_": {"data": "placeholder"},
+            "_SITE_DATA_2_": {"data": {}},
             "_SITE_ACTIONS_2_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_2_": [{
@@ -349,7 +349,7 @@ class TestDocumentLayeringWithSubstitution(
                     "path": "."
                 }
             }],
-            "_SITE_DATA_1_": {"data": "placeholder"},
+            "_SITE_DATA_1_": {"data": {}},
             "_SITE_ACTIONS_1_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_1_": [{
@@ -362,7 +362,7 @@ class TestDocumentLayeringWithSubstitution(
                     "path": "."
                 }
             }],
-            "_SITE_DATA_2_": {"data": "placeholder"},
+            "_SITE_DATA_2_": {"data": {}},
             "_SITE_ACTIONS_2_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_2_": [{
@@ -423,7 +423,7 @@ class TestDocumentLayeringWithSubstitution(
                     "path": "."
                 }
             }],
-            "_SITE_DATA_1_": {"data": "placeholder"},
+            "_SITE_DATA_1_": {"data": {}},
             "_SITE_ACTIONS_1_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_1_": [
@@ -448,7 +448,7 @@ class TestDocumentLayeringWithSubstitution(
                     }
                 }
             ],
-            "_SITE_DATA_2_": {"data": "placeholder"},
+            "_SITE_DATA_2_": {"data": {}},
             "_SITE_ACTIONS_2_": {
                 "actions": [{"method": "merge", "path": "."}]},
             "_SITE_SUBSTITUTIONS_2_": [