cdsbalancer: test cleanup part 2/N (#6554)

internal/credentials/xds/handshake_info.go

@@ -43,12 +43,26 @@ func init() {
 // the Attributes field of resolver.Address.
 type handshakeAttrKey struct{}
 
-// Equal reports whether the handshake info structs are identical (have the
-// same pointer).  This is sufficient as all subconns from one CDS balancer use
-// the same one.
-func (hi *HandshakeInfo) Equal(o any) bool {
-	oh, ok := o.(*HandshakeInfo)
-	return ok && oh == hi
+// Equal reports whether the handshake info structs are identical.
+func (hi *HandshakeInfo) Equal(other *HandshakeInfo) bool {
+	if hi == nil && other == nil {
+		return true
+	}
+	if hi == nil || other == nil {
+		return false
+	}
+	if hi.rootProvider != other.rootProvider ||
+		hi.identityProvider != other.identityProvider ||
+		hi.requireClientCert != other.requireClientCert ||
+		len(hi.sanMatchers) != len(other.sanMatchers) {
+		return false
+	}
+	for i := range hi.sanMatchers {
+		if !hi.sanMatchers[i].Equal(other.sanMatchers[i]) {
+			return false
+		}
+	}
+	return true
 }
 
 // SetHandshakeInfo returns a copy of addr in which the Attributes field is

internal/stubserver/stubserver.go

@@ -216,7 +216,7 @@ func parseCfg(r *manual.Resolver, s string) *serviceconfig.ParseResult {
 // StartTestService spins up a stub server exposing the TestService on a local
 // port. If the passed in server is nil, a stub server that implements only the
 // EmptyCall and UnaryCall RPCs is started.
-func StartTestService(t *testing.T, server *StubServer) *StubServer {
+func StartTestService(t *testing.T, server *StubServer, sopts ...grpc.ServerOption) *StubServer {
 	if server == nil {
 		server = &StubServer{
 			EmptyCallF: func(context.Context, *testpb.Empty) (*testpb.Empty, error) { return &testpb.Empty{}, nil },
@@ -225,7 +225,7 @@ func StartTestService(t *testing.T, server *StubServer) *StubServer {
 			},
 		}
 	}
-	server.StartServer()
+	server.StartServer(sopts...)
 
 	t.Logf("Started test service backend at %q", server.Address)
 	return server