Add network.json existence check

Signed-off-by: Herbert Wolverson <herberticus@gmail.com>

v1.3/integrationCommon.py

@@ -181,6 +181,11 @@ class NetworkGraph:
 			if self.nodes[idx].type == NodeType.client:
 				self.nodes[idx].parentIndex = 0
 
+	def doesNetworkJsonExist(self):
+		# Returns true if "network.json" exists, false otherwise
+		import os
+		return os.path.isfile("network.json")
+
 	def plotNetworkGraph(self, showClients=False):
 		# Requires `pip install graphviz` to function.
 		# You also need to install graphviz on your PC.

v1.3/testGraph.py

@@ -194,6 +194,18 @@ class TestGraph(unittest.TestCase):
         self.assertEqual(len(unconnected), 0)
         self.assertEqual(graph.nodes[6].parentIndex, 0)
 
+    def test_network_json_exists(self):
+        from integrationCommon import NetworkGraph
+        import os
+        if os.path.exists("network.json"):
+            os.remove("network.json")
+        graph = NetworkGraph()
+        self.assertEqual(graph.doesNetworkJsonExist(), False)
+        with open('network.json', 'w') as f:
+            f.write('Dummy')
+        self.assertEqual(graph.doesNetworkJsonExist(), True)
+        os.remove("network.json")
+
     def test_graph_render_to_pdf(self):
         """
         Requires that graphviz be installed with