feat: Remove unused imports across charging engine modules

- Remove unused IntoResponse/warn/error/ChargingError/validate_* imports from api
- Remove unused AsyncCommands/error/ChargingSession/ErrorContext imports from credit_management
- Remove unused ErrorContext/ChargingError imports from engine
- Remove unused ErrorContext import from rating_billing and prefix unused variables with underscore
- Remove unused ErrorContext import from rating_plans_repo
- Remove unused log_error/validate_amount/validate_im

apps/api-server/internal/middleware/redis_ratelimit_test.go

@@ -19,12 +19,13 @@ type MockRedisClient struct {
 }
 
 func (m *MockRedisClient) Eval(ctx context.Context, script string, keys []string, args ...interface{}) *redis.Cmd {
-	callArgs := []any{script}
+	argsList := make([]interface{}, 0, len(keys)+len(args)+1)
+	argsList = append(argsList, script)
 	for _, key := range keys {
-		callArgs = append(callArgs, key)
+		argsList = append(argsList, key)
 	}
-	callArgs = append(callArgs, args...)
-	return m.Called(callArgs...).Get(0).(*redis.Cmd)
+	argsList = append(argsList, args...)
+	return m.Called(argsList...).Get(0).(*redis.Cmd)
 }
 
 func (m *MockRedisClient) Del(ctx context.Context, keys ...string) *redis.IntCmd {
@@ -63,7 +64,8 @@ func TestRedisRateLimiter_Allow(t *testing.T) {
 
 			cmd := redis.NewCmd(context.Background())
 			cmd.SetVal(mockResult)
-			mockClient.On("Eval", mock.AnythingOfType("[]interface {}")).Return(cmd)
+			// Match the actual call signature: script, key, now, window, limit
+			mockClient.On("Eval", mock.AnythingOfType("string"), mock.AnythingOfType("string"), mock.AnythingOfType("int64"), mock.AnythingOfType("int64"), mock.AnythingOfType("int64")).Return(cmd)
 
 			// Create rate limiter with mock client
 			limiter := NewRedisRateLimiter(mockClient, "test", tt.limit, tt.window)
@@ -114,7 +116,7 @@ func TestRedisRateLimitMiddleware(t *testing.T) {
 			// Mock successful rate limit check
 			cmd := redis.NewCmd(context.Background())
 			cmd.SetVal([]interface{}{int64(1), int64(4), int64(time.Now().Unix() + 60)})
-			mockClient.On("Eval", mock.AnythingOfType("[]interface {}")).Return(cmd)
+			mockClient.On("Eval", mock.AnythingOfType("string"), mock.AnythingOfType("string"), mock.AnythingOfType("int64"), mock.AnythingOfType("int64"), mock.AnythingOfType("int64")).Return(cmd)
 
 			// Create rate limiter with mock client
 			limiter := NewRedisRateLimiter(mockClient, "test", 5, time.Minute)

apps/api-server/internal/services/chaos.go

@@ -202,7 +202,13 @@ func (cs *ChaosService) GetActiveExperiments() []*Experiment {
 
 	experiments := make([]*Experiment, 0, len(cs.active))
 	for _, exp := range cs.active {
-		experiments = append(experiments, exp)
+		// Create a copy to avoid race conditions
+		copy := *exp
+		if exp.Finished != nil {
+			finished := *exp.Finished
+			copy.Finished = &finished
+		}
+		experiments = append(experiments, &copy)
 	}
 	return experiments
 }
@@ -213,7 +219,16 @@ func (cs *ChaosService) GetExperimentStatus(id string) (*Experiment, bool) {
 	defer cs.mu.RUnlock()
 
 	exp, exists := cs.active[id]
-	return exp, exists
+	if !exists {
+		return nil, false
+	}
+	// Create a copy to avoid race conditions
+	copy := *exp
+	if exp.Finished != nil {
+		finished := *exp.Finished
+		copy.Finished = &finished
+	}
+	return &copy, true
 }
 
 // Middleware function to inject chaos into HTTP requests