Function verifyUpdateFromResolver

internal/resolver/dns/dns_resolver_test.go:179–227

Waits for a state update from the DNS resolver.

(ctx context.Context, t *testing.T, stateCh chan resolver.State, want resolverUpdate)

// Waits for a state update from the DNS resolver.
func verifyUpdateFromResolver(ctx context.Context, t *testing.T, stateCh chan resolver.State, want resolverUpdate) {
	t.Helper()

	var state resolver.State
	select {
	case <-ctx.Done():
		t.Fatal("Timeout when waiting for a state update from the resolver")
	case state = <-stateCh:
	}

	wantResolverState := resolver.State{
		Addresses: want.addrs,
		Endpoints: want.endpoints,
		ServiceConfig: &serviceconfig.ParseResult{
			Config: want.serviceConfig,
		},
	}
	if len(want.balancerAddrs) > 0 {
		wantResolverState = grpclbstate.Set(wantResolverState, &grpclbstate.State{
			BalancerAddresses: want.balancerAddrs,
		})
	}

	scComparer := cmp.Comparer(func(a, b *serviceconfig.ParseResult) bool {
		var scA serviceconfig.Config
		var scB serviceconfig.Config
		if a != nil {
			scA = a.Config
		}
		if b != nil {
			scB = b.Config
		}
		return internal.EqualServiceConfigForTesting(scA, scB)
	})
	attrComparer := cmp.Comparer(func(a, b *attributes.Attributes) bool {
		if a == nil && b == nil {
			return true
		}
		if a == nil || b == nil {
			return false
		}
		gA := grpclbstate.Get(resolver.State{Attributes: a})
		gB := grpclbstate.Get(resolver.State{Attributes: b})
		return cmp.Equal(gA.BalancerAddresses, gB.BalancerAddresses)
	})
	if diff := cmp.Diff(wantResolverState, state, cmpopts.EquateEmpty(), scComparer, attrComparer); diff != "" {
		t.Fatalf("Got unexpected resolver.State (-want +got):\n%s", diff)
	}
}

// This is the service config used by the fake net.Resolver in its TXT record.
//   - it contains an array of 5 entries