def-schema

Define Object schema and test or validate target object.

Important: Only support ECMAScript 6, both node engine and browsers.

Install

  npm install def-schema

and

let def = require('def-schema');

Example: Basic

    def(String).match(123);   // return false
    def(String).match('123'); // return true
 
    def(String).validate(123); // throw IncompatibleTypeError if not match
    def(String).validate('123'); // passed with silence

def define a new Schema object. Use match to test type of target object, use validate to assert target object.

validate is as same as match except it will throw exception if not match.

Example: Object

  let Person = def({name:String, age:Number});

  Person.match({name:'foo', age: 123, otherPro:'111'});   //return true
  Person.match({age:123});     //return false, missing name
  Person.match({name: 123});   //return false, name is not string

Example: Function

  let Person = def({
    name: String,
    age: Number,
    sayHello: Function
  });

  let person = {
    name: 'test',
    age: 123,
    sayHello() {
      //...
    }
  };

  Person.match(person); // retrun true

Example: Array

  
  def([]).match([1,2,'test']);  //return true
  def([Number]).match([1,2,'test']); //return false
  def([Number]).match([1,2,3]); //return true
  def[Number,String].match([1,'test']); //return true
  def[Number,String].match([1,'test',4,5]); //return true

Example: Combine Array and Object

  let Person = def({
    name: String
    age: Number
    skills: [String]
  });

  let person1 = {name:'foo', age:123, skill: ['js', 'java']};
  let person2 = {name:'foo', age:123, skill: 'js'};

  Person.match(person1); //return true;
  Person.match(person2); //return false;

  def([Person]).match([person1, person2]); //return false;

Example: Customize validator

  let Integer = def.fn(x => def(Number).match(x) && value % 1 === 0 && value >= -2147483648 && value <= 2147483647);

  Integer.match(123); //return true;
  Integer.match(1.23); //return false;

Here, by define the validate function we can decided what is 'Integer' in our program.

Example: Nest definition

Defined new type by leverage existing type, I mean:

  let Integer = def.fn(x => def(Number).match(x) && value % 1 === 0 && value >= -2147483648 && value <= 2147483647);
  let Person = def({
    name: String,
    age: Integer
  });

  Person.match({name: 'foo', age:123}); //return true;
  Person.match({name: 'foo', age:1.23}); //return false;

});	

Example: Opertional property

  let Person = def({
    name: String,
    age: def.opt(Number)
  });

  Person.match({name:'foo', age:1234}); //return true;
  Person.match({name:'foo'}); //return true;
  Person.match({name:'foo', age:'bar'}); //return false;

Example: Other buildin functions

  def.or(String,Number).match('hello');  //return true;
  def.and({name:String},{age:Number}).match({name:'foo', age:123});  //return true;

  let proto = {name:String};
  let target = Object.create(proto);
  def.asProto(proto).match(target);  //return true;


  let Range = def.param( (x, from, to) => def(Number).match(x) && x >= from  && x <= to );

  Range(1,10).match(5); //return true;
  Range(1,10).match(-5); //return return false;

Example: Reuse definition partially

  let Person = def({
    name: {
      first: String,
      last: String
    },
    age: Number
  });

  Person.name.match({first:'foo', last:'bar'}); //return true
  Person.name.match({first:'foo'}); //return false

Example: Generate random instance

  let Person = def({
    name: String,
    age:Number
  })

  Person.random //return random instance which match definition of Person

Thanks :)