express-validator returns 两次验证错误

Question

我想使用 Express-Validator 验证请求 object。假设我有两条路线，一条 GET /users/:id (fetchUserById) 和 POST /users (createUser) 路线

this.router = express.Router();
this.router.route('/').post(this.userRequestValidator.createUser, this.userController.createUser);
this.router.route('/:id').get(this.userRequestValidator.fetchUserById, this.userController.fetchUserById);

如您所见，我在调用控制器逻辑之前调用了验证中间件。首先，我创建了一个基本验证器来处理验证错误并在失败时返回 HTTP 400。

export abstract class RequestValidator {
    protected validate = async (request: Request, response: Response, next: NextFunction): Promise<void> => {
        const errors: Result<ValidationError> = validationResult(request);

        if (!errors.isEmpty()) {
            return res.status(422).json({ errors: errors.array() });
        } else {
            next();
        }
    };
}

我的验证器函数 userRequestValidator.createUser 和 userRequestValidator.fetchUserById 只需扩展 RequestValidator 并实现验证

export class UserRequestValidator extends RequestValidator {
    public createUser = [
        body('username')
            .isString()
            .exists(),
        body('password')
            .isString()
            .exists(),
        this.validate,
    ];

    public fetchUserById = [
        param('id')
            .isString()
            .isUUID()
            .exists(),
        this.validate,
    ];
}

当我打电话给 GET localhost:3000/users/abc 时，我得到了这个回复

{
    "errors": [
        {
            "value": "abc",
            "msg": "Invalid value",
            "param": "id",
            "location": "params"
        }
    ]
}

这是我期待的回应。但是当我用一个空 body 调用 POST localhost:3000/users 时，我得到了这个响应

{
    "errors": [
        {
            "msg": "Invalid value",
            "param": "username",
            "location": "body"
        },
        {
            "msg": "Invalid value",
            "param": "username",
            "location": "body"
        },
        {
            "msg": "Invalid value",
            "param": "password",
            "location": "body"
        },
        {
            "msg": "Invalid value",
            "param": "password",
            "location": "body"
        }
    ]
}

有人知道我该如何解决这个问题或者我的设置有什么问题吗？

Answer 1

我不知道为什么当 req.body 是一个空对象时 - {}，验证器将运行通过验证链的所有节点。您可以再次检查，为每个条件添加每个消息，如下所示：

class UserRequestValidator extends RequestValidator {
  public createUser = [
    body('username')
      .isString().withMessage('username must be a string') // you can see both error messages in the response
      .exists().withMessage('username must be exist'),
    body('password') // the same for this field
      .isString()
      .exists(),
    this.validate,
  ];

  public fetchUserById = [
    param('id') // because id is exist in `req.params`, then only one test has been executed.
      .isString().withMessage('id must be a string')
      .isUUID()
      .exists(),
    this.validate,
  ];
}

我在 https://github.com/express-validator/express-validator/issues/638 中找到了适合您的情况的解决方案，在第一个错误中使用 .bail() 函数停止链。

然后你的验证器 class 会像：

class UserRequestValidator extends RequestValidator {
  public createUser = [
    body('username')
       // always check exists() first
      .exists().withMessage('username must be exist').bail()
      .isString().withMessage('username must be a string').bail(),
    body('password')
      .exists().bail()
      .isString().bail(),
    this.validate,
  ];

  public fetchUserById = [
    param('id')
      .isString()
      .isUUID()
      .exists(),
    this.validate,
  ];
}

Answer 2

您也可以在检索错误数组时将onlyFirstError设置为true。来自 documentation:

If the option onlyFirstError is set to true, then only the first error for each field will be included

用法示例：

function validateRequestParams (req, res, next) {
    const errors = validationResult(req)

    if (errors.isEmpty()) {
        return next()
    } else {
        return res.status(400).json({
            bodyValidationErrors: errors.array({ onlyFirstError: true })
        })
    }
}

express-validator returns 两次验证错误

express-validator returns validation errors twice

javascript

node.js

typescript

express

express-validator