fix bug in doubly nested results getting overwriting eachother

graphcore/graphcore_test.py

@@ -479,6 +479,30 @@ def test_search_outputs(self):
             'xyz.id'
         ]
 
+    def test_nested_results(self):
+        gc = graphcore.Graphcore()
+
+        gc.register_rule(
+            [], 'x.id', function=lambda: [1, 2, 3], cardinality='many'
+        )
+        gc.register_rule(
+            ['x.id'], ['x.ys.z'], function=lambda id:id
+        )
+
+        ret = gc.query({
+            'x.ys': [{
+                'z?': None,
+            }]
+        })
+
+        assert ret == [{
+            'x.ys': [{'z': 1}],
+        }, {
+            'x.ys': [{'z': 2}],
+        }, {
+            'x.ys': [{'z': 3}],
+        }]
+
 
 class TestQuerySearch(unittest.TestCase):
 

graphcore/result_set.py

@@ -83,8 +83,15 @@ def extract_json(self, paths):
 
         return ret
 
-    def copy(self):
-        return Result(self)
+    def deepcopy(self):
+        new_result = {}
+        for k, v in self.result.items():
+            if isinstance(v, ResultSet):
+                v = v.deepcopy()
+
+            new_result[k] = v
+
+        return Result(new_result)
 
     def __getitem__(self, k):
         return self.result[str(k)]
@@ -162,6 +169,16 @@ def filter(self, path, relation):
                     path[1:], relation
                 )
 
+    def deepcopy(self):
+        new_results = []
+        for result in self.results:
+            if isinstance(result, Result):
+                result = result.deepcopy()
+
+            new_results.append(result)
+
+        return ResultSet(new_results)
+
     def __repr__(self):
         return '<ResultSet {str}>'.format(str=str(self))
 
@@ -269,7 +286,8 @@ def apply_rule(data, fn, outputs, cardinality, scope):
 
         new_datas = []
         for values in values_set:
-            new_data = data.copy()
+            # deepcopy: recursively copy Result and ResultSet objects only
+            new_data = data.deepcopy()
             for output, value in zip(outputs, values):
                 new_data[output[0]] = value
             new_datas.append(new_data)