feat(flow): add eq operator to the flow to enable comparison

gnes/flow/__init__.py

@@ -589,7 +589,7 @@ def _build_graph(self, copy_flow: bool) -> 'Flow':
             raise FlowTopologyError('flow is empty?')
 
         # close the loop
-        op_flow._service_nodes[op_flow._frontend]['incomes'].add(op_flow._last_changed_service[-1])
+        op_flow._service_nodes[op_flow._frontend]['incomes'] = {op_flow._last_changed_service[-1]}
 
         # build all edges
         for k, v in op_flow._service_nodes.items():
@@ -726,3 +726,24 @@ def __getstate__(self):
     def __setstate__(self, d):
         self.__dict__.update(d)
         self.logger = set_logger(self.__class__.__name__)
+
+    def __eq__(self, other):
+        """
+        Comparing the topology of a flow with another flow.
+        Identification is defined by whether two flows share the same set of edges.
+
+        :param other: the second flow object
+        :return:
+        """
+
+        if self._build_level.value < Flow.BuildLevel.GRAPH.value:
+            a = self.build(backend=None, copy_flow=True)
+        else:
+            a = self
+
+        if other._build_level.value < Flow.BuildLevel.GRAPH.value:
+            b = other.build(backend=None, copy_flow=True)
+        else:
+            b = other
+
+        return a._service_edges == b._service_edges

tests/test_gnes_flow.py

@@ -212,3 +212,7 @@ def test_flow_add_set(self):
               .build(backend=None))
 
         print(f2.to_url())
+
+        self.assertEqual(f1, f2)
+
+        self.assertNotEqual(f1, f2.add_router('dummy', yaml_path='BaseRouter'))