How to mock a responder flow in corda - corda

Question

I am trying to mock a responder flow inside my unit tests, my responder flow does several validations that deals with configurations and off ledger services. I would like to mock the value to always return a true so that the unit test does not have any dependencies on the other components in the network.
The purpose is only for unit tests, is there any way I could mock the response using API as I am aware that we have to register the responder classes during the mock network setup?

Answer 1

Simply define a dummy responder flow, and register that instead of the real responder flow when setting up the mock network:
public class FlowTests {
private MockNetwork network;
private StartedMockNode a;
private StartedMockNode b;
#InitiatedBy(ExampleFlow.Initiator.class)
public static class DummyResponder extends FlowLogic<Void> {
private final FlowSession otherPartySession;
public DummyResponder(FlowSession otherPartySession) {
this.otherPartySession = otherPartySession;
}
#Suspendable
#Override
public Void call() throws FlowException {
otherPartySession.send(true);
return null;
}
}
#Before
public void setup() {
network = new MockNetwork(ImmutableList.of("com.example.contract"));
a = network.createPartyNode(null);
b = network.createPartyNode(null);
// For real nodes this happens automatically, but we have to manually register the flow for tests.
for (StartedMockNode node : ImmutableList.of(a, b)) {
node.registerInitiatedFlow(DummyResponder.class);
}
network.runNetwork();
}
#After
public void tearDown() {
network.stopNodes();
}
#Rule
public final ExpectedException exception = ExpectedException.none();
#Test
public void flowUsesDummyResponder() throws ExecutionException, InterruptedException {
ExampleFlow.Initiator flow = new ExampleFlow.Initiator(-1, b.getInfo().getLegalIdentities().get(0));
CordaFuture<Boolean> future = a.startFlow(flow);
network.runNetwork();
Boolean bool = future.get();
assertEquals(true, bool);
}
}