Function TestModuleWaitsForAllDependencies

pkg/util/modules/modules_test.go:186–232

(t *testing.T)

}

func TestModuleWaitsForAllDependencies(t *testing.T) {
	var serviceA services.Service

	initA := func() (services.Service, error) {
		serviceA = services.NewIdleService(func(serviceContext context.Context) error {
			// Slow-starting service. Delay is here to verify that service for C is not started before this service
			// has finished starting.
			time.Sleep(1 * time.Second)
			return nil
		}, nil)

		return serviceA, nil
	}

	initC := func() (services.Service, error) {
		return services.NewIdleService(func(serviceContext context.Context) error {
			// At this point, serviceA should be Running, because "C" depends (indirectly) on "A".
			if s := serviceA.State(); s != services.Running {
				return fmt.Errorf("serviceA has invalid state: %v", s)
			}
			return nil
		}, nil), nil
	}

	m := NewManager(log.NewNopLogger())
	m.RegisterModule("A", initA)
	m.RegisterModule("B", nil)
	m.RegisterModule("C", initC)

	// C -> B -> A. Even though B has no service, C must still wait for service A to start, before C can start.
	require.NoError(t, m.AddDependency("B", "A"))
	require.NoError(t, m.AddDependency("C", "B"))

	servsMap, err := m.InitModuleServices("C")
	require.NoError(t, err)

	// Build service manager from services, and start it.
	servs := []services.Service(nil)
	for _, s := range servsMap {
		servs = append(servs, s)
	}

	servManager, err := services.NewManager(servs...)
	require.NoError(t, err)
	assert.NoError(t, services.StartManagerAndAwaitHealthy(context.Background(), servManager))
	assert.NoError(t, services.StopManagerAndAwaitStopped(context.Background(), servManager))
}