feat: support not allow empty for concurrent limiter

middleware/concurrent_limiter.go

@@ -39,6 +39,11 @@ var (
 		Message:    "submit too frequently",
 		Category:   ErrConcurrentLimiterCategory,
 	}
+	ErrNotAllowEmpty = &hes.Error{
+		StatusCode: http.StatusBadRequest,
+		Message:    "empty value is not allowed",
+		Category:   ErrConcurrentLimiterCategory,
+	}
 	ErrRequireLockFunction = errors.New("require lock function")
 )
 
@@ -61,6 +66,8 @@ type (
 		// Lock lock function
 		Lock    ConcurrentLimiterLock
 		Skipper elton.Skipper
+		// NotAllowEmpty is value is empty, will return error
+		NotAllowEmpty bool
 	}
 	// concurrentLimiterKeyInfo the concurrent key's info
 	concurrentLimiterKeyInfo struct {
@@ -142,6 +149,10 @@ func NewConcurrentLimiter(config ConcurrentLimiterConfig) elton.Handler {
 			} else {
 				v = gjson.GetBytes(c.RequestBody, name).String()
 			}
+			if config.NotAllowEmpty && len(v) == 0 {
+				err = ErrNotAllowEmpty
+				return
+			}
 			sb.WriteString(v)
 			if i < keyLength-1 {
 				sb.WriteRune(',')

middleware/concurrent_limiter_test.go

@@ -119,4 +119,20 @@ func TestConcurrentLimiter(t *testing.T) {
 		err := fn(c)
 		assert.Equal("message=key is invalid", err.Error())
 	})
+
+	t.Run("not allow empty", func(t *testing.T) {
+		assert := assert.New(t)
+		fn := NewConcurrentLimiter(ConcurrentLimiterConfig{
+			NotAllowEmpty: true,
+			Keys: []string{
+				"p:id",
+			},
+			Lock: func(key string, c *elton.Context) (success bool, unlock func(), err error) {
+				return
+			},
+		})
+		c := elton.NewContext(nil, httptest.NewRequest("GET", "/", nil))
+		err := fn(c)
+		assert.Equal(ErrNotAllowEmpty, err)
+	})
 }