propertype

a struct constructor/validator library. propertype is a tool to check if an object has the proper type on its properties. as a constructor, it will extract properties defined in its type out of the payload it has been given.

installation

$ npm i propertype --save

possible types

• any: anything
  • required: boolean - default: false - error: propertype-required
• boolean: boolean or string of 'true' or 'false'
  • required: boolean - default: false - error: propertype-required
• number: number or a string of a number
  • required: boolean - default: false - error: propertype-required
  • min: minimum value - error: propertype-number-min
  • max: maximum value - error: propertype-number-max
• string: a string
  • required: boolean - default: false - error: propertype-required
  • min: minimum string length - error: propertype-string-min
  • max: maximum string length - error: propertype-string-max
  • pattern: a regex pattern to test against - default: .* - error: propertype-string-pattern
• object: any object without caring about its properties
  • required: boolean - default: false - error: propertype-required
• oneOf: the value should equal one of the values in its options key
  • required: boolean - default: false - error: propertype-required
  • options: array of possible values - error: propertype-oneof-options
• arrayOf: an array of a specific type
  • required: boolean - default: false - error: propertype-required
  • min: minimum array length - error: propertype-array-min
  • max: maximum array length - error: propertype-array-max
  • type: the specific type that all values in the array should be - default: any
• shape: shape is like a nested propertype config
  • required: boolean - default: false - error: propertype-required
  • types: an object of property configurations, just like its top level one

usage example

const Propertype = require('propertype');

// define a struct
const Person = Propertype({
  name: Propertype.string({ required: true, min: 3, max: 255 }),
  gender: Propertype.oneOf({ required: true, options: [ 'male', 'female' ] }),
  married: Propertype.boolean,
  age: Propertype.number, // you can skip parens if the default type config is good for you (required: false)
  skills: Propertype.arrayOf({ required: true, type: Propertype.string }),
  email: Propertype.email.required, // that's right! you can do this just like prop-types allows you
  outfit: Propertype.shape({ types: {
    shirtColor: Propertype.string,
    jeansColor: Propertype.string,
    sneakerSize: Propertype.number({ min: 30, max: 50 }),
  }}),
  extras: Propertype.any,
});

const payload = {
  name: 'Dariush Alipour',
  gender: 'male',
  married: true,
  age: 26,
  skills: ['js', 'golang'],
  email: '[email protected]',
  outfit: {
    shirtColor: 'black',
    jeansColor: 'blue',
    sneakerSize: 55,
  },
};

// only check/validate types
const errors = Person.validate(payload); // return: { outfit: { sneakerSize: 'propertype-number-max' } }

// explain type rules
const rules = Person.explain();

// construct one
let person;
try {
  person = Person(payload);
} catch(err) {
  /*
    err equals ValidationError {
      code: 400,
      name: 'ValidationError',
      message: 'There are one or more errors in pre-construct validation',
      info: {
        outfit: {
          sneakerSize: 'propertype-number-max',
        },
      },
    }
  */
}