Javascript-检查对象是否具有必需属性的优雅方法

Question

我正在寻找一种好的/优雅的方法来验证javascript对象是否具有必需的属性，到目前为止，这就是我所拥有的：

var fields = ['name','age','address'];
var info = {
  name: "John Doe",
  age: "",
  phone: "123-456-7890"
}


var validateFields = function(o, required_fields) {
  required_fields.forEach(function(field){
    if(o.hasOwnProperty(field)){
      if(o[field]){
        console.log(field + ": " + o[field]);
      }else{
        console.log(field + " exists but is empty");
      }
    }else{
      console.log(field + " doesn't exist in object");
    }
  });
}

validateFields(info, fields);

在普通的javascript中，有没有更有效/更优雅的方法？

编辑：好的，所以我很高兴问我，因为我完全错过了一堆可能的条件，例如零。

随着优雅的出现，验证功能又如何呢？我还有其他情况要检查吗？

var fields = ['name','age','address'];
var info = {
  name: "John Doe",
  age: 0,
  address: false,
  phone: "123-456-7890"
}


var validateFields = function(o, required_fields, null_valid, zero_valid, empty_valid) {
  var invalid_fields = [];
  required_fields.forEach(function(field){
    if(field in o){
      switch(o[field]){
        case '':
          console.log(field + " exists but is empty");
          if(!empty_valid){
            invalid_fields.push(o[field]);
          }
          break;
        case undefined:
          console.log(field + " exists but is undefined");
          invalid_fields.push(o[field]);
          break;
        case null:
          console.log(field + " exists but is null");
          if(!null_valid){
            invalid_fields.push(o[field]);
          }
          break;
        case 0:
          console.log(field + " exists and the value is 0");
          if(!zero_valid){
          }
          invalid_fields.push(o[field]);
          break;
        default:
          console.log(field + ": " + o[field]);
          break;
      }
    }else{
      console.log(field + " doesn't exist in object");
      invalid_fields.push(o[field]);
    }
  });

  return invalid_fields;
}


var invalid = validateFields(info, fields, true, true, false);
console.log(invalid);
if(invalid.length >0){
  console.log("ERROR: Missing fields");
}else{
  console.log("Fields are valid");
}

Answer 1

您可以使用https://github.com/jquense/yup来解决您的问题。

import * as yup from 'yup';

let schema = yup.object().shape({
  name: yup.string().required(),
  age: yup.number().required().positive().integer(),
  address: yup.string().required(),
});

var info = {
  name: "John Doe",
  age: "",
  phone: "123-456-7890"
}

// check validity
schema
  .isValid(info)
  .then(function (valid) {
    valid; // => false
  });

这不仅仅是检查字段是否存在，还确保数据类型正确，例如年龄是非负数。

Answer 2

如果您想要“优雅”，那么您所寻找的就是schema：

var schema = {
  name: function (value) {
    return /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value);
  },
  age: function (value) {
    return !isNaN(value) && parseInt(value) == value && value >= 18;
  },
  phone: function (value) {
    return /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value);
  }
};

var info = {
  name: "John Doe",
  age: "",
  phone: "123-456-7890"
};

function validate(object, schema) {
  var errors = Object.keys(schema).map(function (property) {
    var validator = schema[property];
    
    return [property, validator(object[property])];
  }).reduce(function (errors, pair) {
    if (pair[1] === false) {
      errors.push(new Error(pair[0] + " is invalid."));
    }
    
    return errors;
  }, []);
  
  if (errors.length > 0) {
    errors.forEach(function (error) {
      console.log(error.message);
    });
  } else {
    console.log("info is valid");
  }
}

validate(info, schema);

要解决@AndreFigueiredo的脚手架，您还可以检查，是否object包含该属性：

var schema = {
  name: function (value) {
    return /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value);
  },
  age: function (value) {
    return !isNaN(value) && parseInt(value) == value && value >= 18;
  },
  phone: function (value) {
    return /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value);
  }
};

schema.name.required = true;
schema.age.required = true;

var info = {
  // name: "John Doe",
  age: "",
  phone: "123-456-7890"
};

function validate(object, schema) {
  var errors = Object.keys(schema).map(function (property) {
    var validator = schema[property];
    
    return [property, !validator.required || (property in object), validator(object[property])];
  }).reduce(function (errors, entry) {
    if (!entry[1]) {
      errors.push(new Error(entry[0] + " is required."));
    } else if (entry[1] && !entry[2]) {
      errors.push(new Error(entry[0] + " is invalid."));
    }
    
    return errors;
  }, []);
  
  if (errors.length > 0) {
    errors.forEach(function (error) {
      console.log(error.message);
    });
  } else {
    console.log("info is valid");
  }
}

validate(info, schema);

更新资料

这是一个现代化的解决方案，使用了ECMAScript 6版本的功能，包括解构，箭头功能Object.entries()、、模板文字和for...of：

const schema = {
  name: value => /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value),
  age: value => parseInt(value) === Number(value) && value >= 18,
  phone: value => /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value)
};

let info = {
  name: 'John Doe',
  age: '',
  phone: '123-456-7890'
};

const validate = (object, schema) => Object
  .entries(schema)
  .map(([property, validate]) => [
    property,
    validate(object[property])
  ])
  .reduce((errors, [property, valid]) => {
    if (!valid) {
      errors.push(new Error(`${property} is invalid.`));
    }

    return errors;
  }, []);

const errors = validate(info, schema);

if (errors.length > 0) {
  for (const { message } of errors) {
    console.log(message);
  }
} else {
  console.log('info is valid');
}

required以及validate分别执行和检查的版本：

const schema = {
  name: value => /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value),
  age: value => parseInt(value) === Number(value) && value >= 18,
  phone: value => /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value)
};

schema.name.required = true;
schema.age.required = true;

let info = {
  // name: 'John Doe',
  age: '',
  phone: '123-456-7890'
};

const validate = (object, schema) => Object
  .entries(schema)
  .map(([property, validate]) => [
    property,
    !validate.required || (property in object),
    validate(object[property])
  ]).reduce((errors, [property, canValidate, isValid]) => {
    if (!canValidate) {
      errors.push(new Error(`${property} is required.`));
    } else if (canValidate && !isValid) {
      errors.push(new Error(`${property} is invalid.`));
    }
    
    return errors;
  }, []);

const errors = validate(info, schema);

if (errors.length > 0) {
  for (const { message } of errors) {
    console.log(message);
  }
} else {
  console.log('info is valid');
}

Answer 3

我认为您应该更关心检查它的正确方法，而不是最优雅的方法。我将放置一个链接，指向托德·莫托（Todd Moto）关于此的非常好的帖子：请看一下

简而言之，您的代码应该如下所示：

 var validateFields = function(o, required_fields) {
  required_fields.forEach(function(field){
    if(field in o){
      if((typeof o[field] != 'undefined')){
        console.log(field + ": " + o[field]);
      }else{
        console.log(field + " exists but is undefined");
      }
    }else{
      console.log(field + " doesn't exist in object");
    }
  });
}

注意：检查它是否有价值时要小心，JavaScript 中的许多表达式都是假值（例如 0、假等），但它们是有效值。