fix race condition in test

Author: iwysiu

backend/instancemgmt/instance_manager.go

@@ -19,10 +19,10 @@ var (
 		Name:      "active_instances",
 		Help:      "The number of active plugin instances",
 	})
-	disposeTTL = 5 * time.Second
+	defaultDisposeTTL = 5 * time.Second
 
-	instanceTTL     = 24 * time.Hour
-	instanceCleanup = 48 * time.Hour
+	defaultInstanceTTL     = 24 * time.Hour
+	defaultInstanceCleanup = 48 * time.Hour
 )
 
 // Instance is a marker interface for an instance.
@@ -77,6 +77,10 @@ type InstanceProvider interface {
 
 // New create a new instance manager.
 func New(provider InstanceProvider) InstanceManager {
+	return NewWithOptions(provider, defaultInstanceTTL, defaultInstanceCleanup, defaultDisposeTTL)
+}
+
+func NewWithOptions(provider InstanceProvider, instanceTTL, instanceCleanup, disposeTTL time.Duration) InstanceManager {
 	if provider == nil {
 		panic("provider cannot be nil")
 	}

backend/instancemgmt/instance_manager_test.go

@@ -21,7 +21,7 @@ func TestInstanceManager(t *testing.T) {
 	}
 
 	tip := &testInstanceProvider{}
-	im := New(tip)
+	im := NewWithOptions(tip, defaultInstanceTTL, defaultInstanceCleanup, time.Millisecond)
 
 	t.Run("When getting instance should create a new instance", func(t *testing.T) {
 		instance, err := im.Get(ctx, pCtx)
@@ -43,11 +43,6 @@ func TestInstanceManager(t *testing.T) {
 					Updated: time.Now(),
 				},
 			}
-			origDisposeTTL := disposeTTL
-			disposeTTL = time.Millisecond
-			t.Cleanup(func() {
-				disposeTTL = origDisposeTTL
-			})
 			newInstance, err := im.Get(ctx, pCtxUpdated)
 
 			t.Run("New instance should be created", func(t *testing.T) {
@@ -79,17 +74,8 @@ func TestInstanceManagerExpiration(t *testing.T) {
 		},
 	}
 
-	origInstanceTTL := instanceTTL
-	instanceTTL = time.Millisecond
-	origInstanceCleanup := instanceCleanup
-	instanceCleanup = 2 * time.Millisecond
-	t.Cleanup(func() {
-		instanceTTL = origInstanceTTL
-		instanceCleanup = origInstanceCleanup
-	})
-
 	tip := &testInstanceProvider{}
-	im := New(tip)
+	im := NewWithOptions(tip, time.Millisecond, 2*time.Millisecond, defaultDisposeTTL)
 
 	instance, err := im.Get(ctx, pCtx)
 	require.NoError(t, err)
@@ -157,12 +143,6 @@ func TestInstanceManagerConcurrency(t *testing.T) {
 	})
 
 	t.Run("Check possible race condition issues when re-creating instance on settings update", func(t *testing.T) {
-		origDisposeTTL := disposeTTL
-		disposeTTL = time.Millisecond
-		t.Cleanup(func() {
-			disposeTTL = origDisposeTTL
-		})
-
 		ctx := context.Background()
 		initialPCtx := backend.PluginContext{
 			OrgID: 1,
@@ -171,7 +151,7 @@ func TestInstanceManagerConcurrency(t *testing.T) {
 			},
 		}
 		tip := &testInstanceProvider{}
-		im := New(tip)
+		im := NewWithOptions(tip, defaultInstanceTTL, defaultInstanceCleanup, time.Millisecond)
 		// Creating initial instance with old contexts
 		instanceToDispose, _ := im.Get(ctx, initialPCtx)