Method TestPickFirstLeaf_HealthUpdates

balancer/pickfirst/pickfirst_ext_test.go:2502–2596

Test mocks the updates sent to the health listener and verifies that the balancer correctly reports the health state once the SubConn's connectivity state becomes READY.

(t *testing.T)

// balancer correctly reports the health state once the SubConn's connectivity
// state becomes READY.
func (s) TestPickFirstLeaf_HealthUpdates(t *testing.T) {
	// Wrap the clientconn to intercept NewSubConn.
	// Capture the health list by wrapping the SC.
	// Wrap the picker to unwrap the SC.
	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()
	healthListenerCh := make(chan func(balancer.SubConnState))
	scConnectivityStateCh := make(chan balancer.SubConnState, 5)

	bf := stub.BalancerFuncs{
		Init: func(bd *stub.BalancerData) {
			ccw := &healthListenerCapturingCCWrapper{
				ClientConn:       bd.ClientConn,
				healthListenerCh: healthListenerCh,
				subConnStateCh:   scConnectivityStateCh,
			}
			bd.ChildBalancer = balancer.Get(pfbalancer.Name).Build(ccw, bd.BuildOptions)
		},
		Close: func(bd *stub.BalancerData) {
			bd.ChildBalancer.Close()
		},
		UpdateClientConnState: func(bd *stub.BalancerData, ccs balancer.ClientConnState) error {
			ccs.ResolverState = pfbalancer.EnableHealthListener(ccs.ResolverState)
			return bd.ChildBalancer.UpdateClientConnState(ccs)
		},
	}

	stub.Register(t.Name(), bf)
	svcCfg := fmt.Sprintf(`{ "loadBalancingConfig": [{%q: {}}] }`, t.Name())
	backend := stubserver.StartTestService(t, nil)
	defer backend.Stop()
	opts := []grpc.DialOption{
		grpc.WithTransportCredentials(insecure.NewCredentials()),
		grpc.WithDefaultServiceConfig(svcCfg),
	}
	cc, err := grpc.NewClient(backend.Address, opts...)
	if err != nil {
		t.Fatalf("grpc.NewClient(%q) failed: %v", backend.Address, err)

	}
	defer cc.Close()
	cc.Connect()

	var healthListener func(balancer.SubConnState)
	select {
	case healthListener = <-healthListenerCh:
	case <-ctx.Done():
		t.Fatal("Context timed out waiting for health listener to be registered.")
	}

	// Wait for the raw connectivity state to become READY. The LB policy should
	// wait for the health updates before transitioning the channel to READY.
	for {
		var scs balancer.SubConnState
		select {
		case scs = <-scConnectivityStateCh:
		case <-ctx.Done():
			t.Fatal("Context timed out waiting for the SubConn connectivity state to become READY.")