Move subgraph attribute copies tests to a separate file.

1 files changed, 84 insertions, 0 deletions

diff --git a/networkx/algorithms/components/tests/test_subgraph_copies.py b/networkx/algorithms/components/tests/test_subgraph_copies.py
new file mode 100644
index 00000000..b09e245b
--- /dev/null
+++ b/networkx/algorithms/components/tests/test_subgraph_copies.py
@@ -0,0 +1,84 @@
+""" Tests for subgraphs attributes
+"""
+from copy import deepcopy
+from nose.tools import assert_equal
+import networkx as nx
+
+class TestSubgraphAttributesDicts:
+
+    def setUp(self):
+        self.undirected = [
+            nx.connected_component_subgraphs,
+            nx.biconnected_component_subgraphs,
+        ]
+        self.directed = [
+            nx.weakly_connected_component_subgraphs,
+            nx.strongly_connected_component_subgraphs,
+            nx.attracting_component_subgraphs,
+        ]
+        self.subgraph_funcs = self.undirected + self.directed
+        
+        self.D = nx.DiGraph()
+        self.D.add_edge(1, 2, eattr='red')
+        self.D.add_edge(2, 1, eattr='red')
+        self.D.node[1]['nattr'] = 'blue'
+        self.D.graph['gattr'] = 'green'
+
+        self.G = nx.Graph()
+        self.G.add_edge(1, 2, eattr='red')
+        self.G.node[1]['nattr'] = 'blue'
+        self.G.graph['gattr'] = 'green'
+
+    def test_subgraphs_default_copy_behavior(self):
+        # Test the default behavior of subgraph functions 
+        # For the moment (1.10) the default is to copy
+        for subgraph_func in self.subgraph_funcs:
+            G = deepcopy(self.G if subgraph_func in self.undirected else self.D)
+            SG = list(subgraph_func(G))[0]
+            assert_equal(SG[1][2]['eattr'], 'red')
+            assert_equal(SG.node[1]['nattr'], 'blue')
+            assert_equal(SG.graph['gattr'], 'green')
+            SG[1][2]['eattr'] = 'foo'
+            assert_equal(G[1][2]['eattr'], 'red')
+            assert_equal(SG[1][2]['eattr'], 'foo')
+            SG.node[1]['nattr'] = 'bar'
+            assert_equal(G.node[1]['nattr'], 'blue')
+            assert_equal(SG.node[1]['nattr'], 'bar')
+            SG.graph['gattr'] = 'baz'
+            assert_equal(G.graph['gattr'], 'green')
+            assert_equal(SG.graph['gattr'], 'baz')
+
+    def test_subgraphs_copy(self):
+        for subgraph_func in self.subgraph_funcs:
+            test_graph = self.G if subgraph_func in self.undirected else self.D
+            G = deepcopy(test_graph)
+            SG = list(subgraph_func(G, copy=True))[0]
+            assert_equal(SG[1][2]['eattr'], 'red')
+            assert_equal(SG.node[1]['nattr'], 'blue')
+            assert_equal(SG.graph['gattr'], 'green')
+            SG[1][2]['eattr'] = 'foo'
+            assert_equal(G[1][2]['eattr'], 'red')
+            assert_equal(SG[1][2]['eattr'], 'foo')
+            SG.node[1]['nattr'] = 'bar'
+            assert_equal(G.node[1]['nattr'], 'blue')
+            assert_equal(SG.node[1]['nattr'], 'bar')
+            SG.graph['gattr'] = 'baz'
+            assert_equal(G.graph['gattr'], 'green')
+            assert_equal(SG.graph['gattr'], 'baz')
+
+    def test_subgraphs_no_copy(self):
+        for subgraph_func in self.subgraph_funcs:
+            G = deepcopy(self.G if subgraph_func in self.undirected else self.D)
+            SG = list(subgraph_func(G, copy=False))[0]
+            assert_equal(SG[1][2]['eattr'], 'red')
+            assert_equal(SG.node[1]['nattr'], 'blue')
+            assert_equal(SG.graph['gattr'], 'green')
+            SG[1][2]['eattr'] = 'foo'
+            assert_equal(G[1][2]['eattr'], 'foo')
+            assert_equal(SG[1][2]['eattr'], 'foo')
+            SG.node[1]['nattr'] = 'bar'
+            assert_equal(G.node[1]['nattr'], 'bar')
+            assert_equal(SG.node[1]['nattr'], 'bar')
+            SG.graph['gattr'] = 'baz'
+            assert_equal(G.graph['gattr'], 'baz')
+            assert_equal(SG.graph['gattr'], 'baz')