Moleculer.services mock services helper function. With this function you can mock services by mocking broker.call and returning the desired result for a service that you don't wan't to test right now.

moleculer-broker-call-mocker.js

function mockBrokerCall(broker, serviceInstance, callSignature, implementationFn) {
  if (serviceInstance.broker.call.mockRestore) {
    serviceInstance.broker.call.mockRestore();
  }

  const originalImplementation = serviceInstance.broker.call;

  // reimplemento la broker.call per verificare se viene chiamata con il servizio
  // da mockare e ritornare l'implementazione passata
  const mockedFn = jest.fn(
    function() {
      // recupero il servizio chiamato nella call
      const actualSignature = arguments[0];
      if (callSignature === actualSignature) {
        // passo tutti gli argomenti e come contesto il broker
        return Promise.resolve(implementationFn.call(broker, ...arguments));
      }
      return Promise.resolve(originalImplementation.call(broker, ...arguments));
    }
  );
  serviceInstance.broker.call = mockedFn;
  return serviceInstance.broker.call;
}

module.exports = {
  mockBrokerCall
};