feat: support ExtractClaimsFromToken func (#198)

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

auth_jwt.go

@@ -693,6 +693,20 @@ func ExtractClaims(c *gin.Context) MapClaims {
 	return claims.(MapClaims)
 }
 
+// ExtractClaimsFromToken help to extract the JWT claims from token
+func ExtractClaimsFromToken(token *jwt.Token) MapClaims {
+	if token == nil {
+		return make(MapClaims)
+	}
+
+	claims := MapClaims{}
+	for key, value := range token.Claims.(jwt.MapClaims) {
+		claims[key] = value
+	}
+
+	return claims
+}
+
 // GetToken help to get the JWT token string
 func GetToken(c *gin.Context) string {
 	token, exists := c.Get("JWT_TOKEN")

auth_jwt_test.go

@@ -1151,6 +1151,13 @@ func TestCheckTokenString(t *testing.T) {
 		Unauthorized: func(c *gin.Context, code int, message string) {
 			c.String(code, message)
 		},
+		PayloadFunc: func(data interface{}) MapClaims {
+			if v, ok := data.(MapClaims); ok {
+				return v
+			}
+
+			return nil
+		},
 	})
 
 	handler := ginHandler(authMiddleware)
@@ -1169,6 +1176,11 @@ func TestCheckTokenString(t *testing.T) {
 			assert.Equal(t, http.StatusOK, r.Code)
 		})
 
+	token, err := authMiddleware.ParseTokenString(userToken)
+	assert.NoError(t, err)
+	claims := ExtractClaimsFromToken(token)
+	assert.Equal(t, "admin", claims["identity"])
+
 	time.Sleep(2 * time.Second)
 
 	r.GET("/auth/hello").
@@ -1179,6 +1191,7 @@ func TestCheckTokenString(t *testing.T) {
 			assert.Equal(t, http.StatusUnauthorized, r.Code)
 		})
 
-	_, err := authMiddleware.ParseTokenString(userToken)
+	_, err = authMiddleware.ParseTokenString(userToken)
 	assert.Error(t, err)
+	assert.Equal(t, MapClaims{}, ExtractClaimsFromToken(nil))
 }