diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 8a156e0f9..ea911c86a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -81,25 +81,25 @@ jobs:
         run: |
           make build
 
-      - name: Verify core rendering (windows-latest)
+      - name: Test (windows-latest)
         if: matrix.step == 'check' && matrix.os == 'windows-latest' && always()
         shell: msys2 {0}
         env:
           MESA_GL_VERSION_OVERRIDE: 3.3COMPAT
         run: |
-          GL_CTX=-autoGlContext make verify-cores
+          GL_CTX=-autoGlContext make test verify-cores
 
-      - name: Verify core rendering (ubuntu-latest)
+      - name: Test (ubuntu-latest)
         if: matrix.step == 'check' && matrix.os == 'ubuntu-latest' && always()
         env:
           MESA_GL_VERSION_OVERRIDE: 3.3COMPAT
         run: |
-          GL_CTX=-autoGlContext xvfb-run --auto-servernum make verify-cores
+          GL_CTX=-autoGlContext xvfb-run --auto-servernum make test verify-cores
 
-      - name: Verify core rendering (macos-latest)
+      - name: Test (macos-latest)
         if: matrix.step == 'check' && matrix.os == 'macos-latest' && always()
         run: |
-          make verify-cores
+          make test verify-cores
 
       - uses: actions/upload-artifact@v3
         if: matrix.step == 'check' && always()
diff --git a/Makefile b/Makefile
index f8097ac01..f0afe6ad7 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,8 @@ CGO_CFLAGS='-g -O3 -funroll-loops'
 CGO_LDFLAGS='-g -O3'
 GO_TAGS=static
 
+.PHONY: clean test
+
 fmt:
 	@goimports -w cmd pkg tests
 	@gofmt -s -w cmd pkg tests
@@ -32,6 +34,9 @@ build.worker:
 
 build: build.coordinator build.worker
 
+test:
+	go test -v ./pkg/...
+
 verify-cores:
 	go test -run TestAll ./pkg/worker/room -v -renderFrames $(GL_CTX) -outputPath "../../../_rendered"
 
diff --git a/pkg/config/config.yaml b/pkg/config/config.yaml
index 30737b082..1944c8f3f 100644
--- a/pkg/config/config.yaml
+++ b/pkg/config/config.yaml
@@ -205,6 +205,7 @@ emulator:
         nes:
           lib: nestopia_libretro
           roms: [ "nes" ]
+          scale: 3
         snes:
           lib: snes9x_libretro
           roms: [ "smc", "sfc", "swc", "fig", "bs" ]
diff --git a/pkg/worker/caged/libretro/frontend_test.go b/pkg/worker/caged/libretro/frontend_test.go
index bf3c3c313..fc0f23418 100644
--- a/pkg/worker/caged/libretro/frontend_test.go
+++ b/pkg/worker/caged/libretro/frontend_test.go
@@ -9,6 +9,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"runtime"
 	"sync"
 	"testing"
 	"unsafe"
@@ -16,7 +17,9 @@ import (
 	"github.com/giongto35/cloud-game/v3/pkg/config"
 	"github.com/giongto35/cloud-game/v3/pkg/logger"
 	"github.com/giongto35/cloud-game/v3/pkg/worker/caged/app"
+	"github.com/giongto35/cloud-game/v3/pkg/worker/caged/libretro/manager"
 	"github.com/giongto35/cloud-game/v3/pkg/worker/caged/libretro/nanoarch"
+	"github.com/giongto35/cloud-game/v3/pkg/worker/thread"
 )
 
 type testRun struct {
@@ -44,6 +47,20 @@ type EmulatorPaths struct {
 	save   string
 }
 
+var root string
+
+var syncOnce sync.Once
+
+func init() {
+	runtime.LockOSThread()
+	p, _ := filepath.Abs("../../../../")
+	root = p + string(filepath.Separator)
+}
+
+func TestMain(m *testing.M) {
+	thread.Wrap(func() { os.Exit(m.Run()) })
+}
+
 // GetEmulatorMock returns a properly stubbed emulator instance.
 // Due to extensive use of globals -- one mock instance is allowed per a test run.
 // Don't forget to init one image channel consumer, it will lock-out otherwise.
@@ -55,12 +72,35 @@ func GetEmulatorMock(room string, system string) *EmulatorMock {
 	if _, err := config.LoadConfig(&conf, ""); err != nil {
 		panic(err)
 	}
+	conf.Worker.Library.BasePath = filepath.FromSlash(root + "/assets/games")
+
+	conf.Emulator.Libretro.Cores.Repo.ExtLock =
+		filepath.FromSlash(filepath.Join(root, "tests", ".cr", "cloud-game.lock"))
+
+	conf.Emulator.Libretro.Cores.Paths.Libs =
+		filepath.FromSlash(root + conf.Emulator.Libretro.Cores.Paths.Libs)
+	conf.Emulator.LocalPath = filepath.FromSlash(filepath.Join(root, "tests", conf.Emulator.LocalPath))
+	conf.Emulator.Storage = filepath.FromSlash(filepath.Join(root, "tests", "storage"))
+
+	for k, config_ := range conf.Emulator.Libretro.Cores.List {
+		if config_.IsGlAllowed {
+			config_.AutoGlContext = true
+		}
+		conf.Emulator.Libretro.Cores.List[k] = config_
+	}
+
+	l := logger.Default()
+
+	syncOnce.Do(func() {
+		if err := manager.CheckCores(conf.Emulator, l); err != nil {
+			l.Warn().Err(err).Msgf("a Libretro cores sync fail")
+		}
+	})
 
 	meta := conf.Emulator.GetLibretroCoreConfig(system)
 
 	nano := nanoarch.NewNano(cleanPath(conf.Emulator.LocalPath))
 
-	l := logger.Default()
 	l2 := l.Extend(l.Level(logger.ErrorLevel).With())
 	nano.SetLogger(l2)
 
@@ -115,10 +155,15 @@ func (emu *EmulatorMock) loadRom(game string) {
 		log.Fatal(err)
 	}
 	w, h := emu.FrameSize()
-	if emu.conf.Scale == 0 {
-		emu.conf.Scale = 1
+
+	conf := emu.conf.GetLibretroCoreConfig(game)
+
+	scale := 1.0
+	if conf.Scale > 1 {
+		scale = conf.Scale
 	}
-	emu.SetViewport(w, h, emu.conf.Scale)
+	emu.scale = scale
+	emu.SetViewport(w, h)
 }
 
 // Shutdown closes the emulator and cleans its resources.
diff --git a/pkg/worker/caged/libretro/manager/http.go b/pkg/worker/caged/libretro/manager/http.go
index 8609314e9..1f2dbc881 100644
--- a/pkg/worker/caged/libretro/manager/http.go
+++ b/pkg/worker/caged/libretro/manager/http.go
@@ -2,6 +2,7 @@ package manager
 
 import (
 	"os"
+	"path/filepath"
 
 	"github.com/giongto35/cloud-game/v3/pkg/config"
 	"github.com/giongto35/cloud-game/v3/pkg/logger"
@@ -31,6 +32,15 @@ func NewRemoteHttpManager(conf config.LibretroConfig, log *logger.Logger) Manage
 	}
 	log.Debug().Msgf("Using .lock file: %v", fileLock)
 
+	if err := os.MkdirAll(filepath.Dir(fileLock), 0770); err != nil {
+		log.Error().Err(err).Msgf("couldn't create lock")
+	} else {
+		f, err := os.Create(fileLock)
+		if err != nil {
+			log.Error().Err(err).Msgf("couldn't create lock")
+		}
+		_ = f.Close()
+	}
 	ar, err := arch.Guess()
 	if err != nil {
 		log.Error().Err(err).Msg("couldn't get Libretro core file extension")
@@ -73,8 +83,16 @@ func CheckCores(conf config.Emulator, log *logger.Logger) error {
 
 func (m *Manager) Sync() error {
 	// IPC lock if multiple worker processes on the same machine
-	m.fmu.Lock()
-	defer m.fmu.Unlock()
+	err := m.fmu.Lock()
+	if err != nil {
+		m.log.Error().Err(err).Msg("file lock fail")
+	}
+	defer func() {
+		err := m.fmu.Unlock()
+		if err != nil {
+			m.log.Error().Err(err).Msg("file unlock fail")
+		}
+	}()
 
 	installed, err := m.GetInstalled(m.arch.LibExt)
 	if err != nil {
diff --git a/pkg/worker/room/room_test.go b/pkg/worker/room/room_test.go
index 5d082229e..3ebeb51ba 100644
--- a/pkg/worker/room/room_test.go
+++ b/pkg/worker/room/room_test.go
@@ -255,6 +255,9 @@ func fixEmulators(config *config.WorkerConfig, autoGlContext bool) {
 	config.Emulator.LocalPath = filepath.FromSlash(filepath.Join(root, "tests", config.Emulator.LocalPath))
 	config.Emulator.Storage = filepath.FromSlash(filepath.Join(root, "tests", "storage"))
 
+	config.Emulator.Libretro.Cores.Repo.ExtLock =
+		filepath.FromSlash(filepath.Join(root, "tests", ".cr", "cloud-game.lock"))
+
 	for k, conf := range config.Emulator.Libretro.Cores.List {
 		if conf.IsGlAllowed && autoGlContext {
 			conf.AutoGlContext = true
diff --git a/pkg/worker/thread/mainthread_darwin_test.go b/pkg/worker/thread/mainthread_darwin_test.go
index bab4a92c3..15ce9328f 100644
--- a/pkg/worker/thread/mainthread_darwin_test.go
+++ b/pkg/worker/thread/mainthread_darwin_test.go
@@ -1,16 +1,14 @@
 package thread
 
-import "testing"
+import (
+	"os"
+	"testing"
+)
 
-func init() {
-	runtime.LockOSThread()
+func TestMain(m *testing.M) {
+	Wrap(func() { os.Exit(m.Run()) })
 }
 
 func TestMainThread(t *testing.T) {
-	value := 0
-	fn := func() { value = 1 }
-	Main(fn)
-	if value != 1 {
-		t.Errorf("wrong value %v", value)
-	}
+	_ = 10
 }