Add test for event forwarding from a subgraph

spec/Subgraph.coffee

@@ -511,3 +511,49 @@ describe 'NoFlo Graph component', ->
           return done err if err
           sendNext()
       return
+  describe 'event forwarding on parent network', ->
+    graph = null
+    network = null
+    before (done) ->
+      graph = new noflo.Graph 'main'
+      graph.baseDir = root
+      network = new noflo.Network graph
+      network.loader.listComponents (err) ->
+        return done err if err
+        network.loader.components.Split = Split
+        network.loader.components.Merge = SubgraphMerge
+        sg = new noflo.Graph 'Subgraph'
+        sg.addNode 'A', 'Split'
+        sg.addNode 'B', 'Merge'
+        sg.addEdge 'A', 'out', 'B', 'in'
+        sg.addInport 'in', 'A', 'in'
+        sg.addOutport 'out', 'B', 'out'
+        network.loader.registerGraph 'foo', 'AB', sg, (err) ->
+          return done err if err
+          network.connect done
+    it 'should instantiate the subgraph when node is added', (done) ->
+      setTimeout ->
+        chai.expect(network.processes).not.to.be.empty
+        chai.expect(network.processes.Sub).to.exist
+        done()
+      , 10
+      graph.addNode 'Sub', 'foo/AB'
+      graph.addNode 'Split', 'Split'
+      graph.addEdge 'Sub', 'out', 'Split', 'in'
+    it 'should be possible to start the graph', (done) ->
+      network.start done
+    it 'should forward IP events', (done) ->
+      network.once 'ip', (ip) ->
+        chai.expect(ip.id).to.equal 'DATA -> IN Sub()'
+        chai.expect(ip.type).to.equal 'data'
+        chai.expect(ip.data).to.equal 'foo'
+        chai.expect(ip.subgraph).to.be.undefined
+        network.once 'ip', (ip) ->
+          chai.expect(ip.id).to.equal 'A() OUT -> IN B()'
+          chai.expect(ip.type).to.equal 'data'
+          chai.expect(ip.data).to.equal 'foo'
+          chai.expect(ip.subgraph).to.eql [
+            'Sub'
+          ]
+          done()
+      graph.addInitial 'foo', 'Sub', 'in'