Improve fake server interface (viamrobotics#3698)

config/reader_test.go

@@ -34,24 +34,10 @@ func TestFromReader(t *testing.T) {
 		test.That(t, os.IsNotExist(err), test.ShouldBeTrue)
 	}
 
-	setupFakeServer := func(t *testing.T) (*testutils.FakeCloudServer, func()) {
-		t.Helper()
-
-		logger := logging.NewTestLogger(t)
-
-		fakeServer, err := testutils.NewFakeCloudServer(context.Background(), logger)
-		test.That(t, err, test.ShouldBeNil)
-		cleanup := func() {
-			test.That(t, fakeServer.Shutdown(), test.ShouldBeNil)
-		}
-
-		return fakeServer, cleanup
-	}
-
 	t.Run("online", func(t *testing.T) {
 		setupClearCache(t)
 
-		fakeServer, cleanup := setupFakeServer(t)
+		fakeServer, cleanup := testutils.NewFakeCloudServer(t, ctx, logger)
 		defer cleanup()
 
 		cloudResponse := &Cloud{
@@ -114,7 +100,7 @@ func TestFromReader(t *testing.T) {
 		test.That(t, err, test.ShouldBeNil)
 		defer clearCache(robotPartID)
 
-		fakeServer, cleanup := setupFakeServer(t)
+		fakeServer, cleanup := testutils.NewFakeCloudServer(t, ctx, logger)
 		defer cleanup()
 		fakeServer.FailOnConfigAndCertsWith(context.DeadlineExceeded)
 		fakeServer.StoreDeviceConfig(robotPartID, nil, nil)

config/testutils/fake_cloud.go

@@ -7,8 +7,10 @@ import (
 	"net"
 	"net/http"
 	"sync"
+	"testing"
 
 	pb "go.viam.com/api/app/v1"
+	"go.viam.com/test"
 	"go.viam.com/utils"
 	"go.viam.com/utils/rpc"
 	"google.golang.org/grpc/codes"
@@ -42,10 +44,12 @@ type configAndCerts struct {
 }
 
 // NewFakeCloudServer creates and starts a new grpc server for the Viam Cloud.
-func NewFakeCloudServer(ctx context.Context, logger logging.Logger) (*FakeCloudServer, error) {
+func NewFakeCloudServer(t *testing.T, ctx context.Context, logger logging.Logger) (*FakeCloudServer, func()) { //nolint:revive
+	t.Helper()
+
 	listener, err := net.ListenTCP("tcp", &net.TCPAddr{Port: 0})
 	if err != nil {
-		return nil, err
+		t.Fatalf("failed to start listener for fake cloud server")
 	}
 
 	server := &FakeCloudServer{
@@ -63,7 +67,7 @@ func NewFakeCloudServer(ctx context.Context, logger logging.Logger) (*FakeCloudS
 		)),
 		rpc.WithWebRTCServerOptions(rpc.WebRTCServerOptions{Enable: false}))
 	if err != nil {
-		return nil, err
+		t.Fatalf("failed to create new fake cloud server")
 	}
 
 	err = server.rpcServer.RegisterServiceServer(
@@ -73,9 +77,8 @@ func NewFakeCloudServer(ctx context.Context, logger logging.Logger) (*FakeCloudS
 		pb.RegisterRobotServiceHandlerFromEndpoint,
 	)
 	if err != nil {
-		return nil, err
+		t.Fatalf("failed to register robot service for new fake cloud server")
 	}
-
 	server.exitWg.Add(1)
 	utils.PanicCapturingGo(func() {
 		defer server.exitWg.Done()
@@ -85,8 +88,10 @@ func NewFakeCloudServer(ctx context.Context, logger logging.Logger) (*FakeCloudS
 			logger.Warnf("Error shutting down grpc server", "error", err)
 		}
 	})
-
-	return server, nil
+	shutdown := func() {
+		test.That(t, server.Shutdown(), test.ShouldBeNil)
+	}
+	return server, shutdown
 }
 
 // FailOnConfigAndCerts if `failure` is true the server will return an Internal error on

config/watcher_test.go

@@ -187,11 +187,8 @@ func TestNewWatcherCloud(t *testing.T) {
 
 	deviceID := primitive.NewObjectID().Hex()
 
-	fakeServer, err := testutils.NewFakeCloudServer(context.Background(), logger)
-	test.That(t, err, test.ShouldBeNil)
-	defer func() {
-		test.That(t, fakeServer.Shutdown(), test.ShouldBeNil)
-	}()
+	fakeServer, cleanup := testutils.NewFakeCloudServer(t, context.Background(), logger)
+	defer cleanup()
 
 	storeConfigInServer := func(cfg config.Config) {
 		cloudConfProto, err := config.CloudConfigToProto(cfg.Cloud)