kasper - a very simple object schema validator

A javascript package which helps you validate your objects against a specified schema.

Application

This package is useful in validations for cases such as:

1. In applications where you frequently interact with external services and I/O is in form of objects.
2. In code flows where object needs to be validated for any undefined/null values before executing main function logic.
3. In places where you need to set default values if something mismatches from schema (configuration variables)
4. In places where you write a final schema and partially validate your object as it keys get added to it as the code flows.

Further explanation: https://medium.com/@anujkumargupta/why-validate-your-objects-with-kasper-8aa7eb3093e1

Installation

npm install --save kasper

Github repository

https://github.com/anuj3918/object-validator.git

Code example

const kasper = require('kasper');

const schema = {
	id: { keyType: [ 'string' ], notAllowed: [ 'abc001' ], regExp: /abc/g },
	mode: { keyType: [ 'string' ], allowed: [ 'card' ] },
	amount: { keyType: [ 'number' ], min: 0, default: 0 },
	currency: { keyType: [ 'string' ], default: 'usd', allowed: [ 'inr', 'usd' ], notAllowed: [ '' ] },
	cardDetails: {
		number: { keyType: [ 'string' ], size: [ 12, 16, 20 ] },
		cvc: { keyType: [ 'number' ], isInteger: true },
		month: { keyType: [ 'number' ], range: [ 1, 12 ], isInteger: true },
		year: { keyType: [ 'number' ], range: [ 2018, 2050 ], isInteger: true }
	},
	errors: { keyType: [ 'error', 'null' ], default: null },
	datetime: { keyType: [ 'date', 'string' ], default: new Date() },
	birthday: { keyType: [ 'date' ], range: ['25/11/1995 00:00:00', '31/12/2050 23:59:59'] },
	countries: { keyType: [ 'array' ], allowed: [ [ 'india', 'nepal' ], [ 'england', 'iceland' ] ], notAllowed: [ [] ] }
};

const payload = {
	id: 'abc1234',
	mode: 'card',
	amount: 123.45,
	currency: '',
	cardDetails: {
		number: '4444555566667777',
		cvc: 987,
		month: 2,
		year: 2020
	},
	errors: undefined,
	datetime: null,
	birthday: new Date(),
	countries: ['india', 'nepal']
};

const options = {
	matchPartialSchema: true,    // default: false
	strictMatch: false,	     // default: false
	setDefaultValues: true	     // default: true
};

// You can omit the last parameter i.e. options if you want to use default options only
const response = kasper.validate(schema, payload, options);
console.log(response);

// Output
let output = {
	err: null,
	message: 'Validations successful',
	result: {
		id: 'abc1234',
		mode: 'card',
		amount: 123.45,
		currency: 'usd',
		cardDetails: { number: '4444555566667777', cvc: 987 month: 2, year: 2020},
		errors: null,
		datetime: 2018-08-30T19:30:18.386Z,
		birthday: 2018-08-30T19:30:18.386Z,
		countries: ['india', 'nepal']
	}
};

Schema flags with decsription

| Flag | Value | Description | |-----------|-----------|-------------| | keyType | ['number', 'boolean', 'string', 'object', 'array', 'null', 'date', 'error'] | mandatory Specify the types for key as an array | | allowed | ['india', 'us', 'china'] (array of values) | Checks if value of key is among these values | | notAllowed | ['', 'delhi', 'mumbai' ] (array of values) | Checks if value of key is not among these values | | size | [1,3,5] (Array of integers) | Checks if length of string/array is in one of the given sizes. Use only with string/array | | regExp | /hello/g (a valid regular exp) | Checks if string matches a regular expression | | max | 100 (any numerical value) | Checks if number value is not greater than max | | min | 1 (any numerical value) | Checks if number value is not less than min | | range | [1, 10] | Number: Checks if number lies in the specified range (both limits inclusive) | | range | ['25/11/1995 00:00:00', '31/12/2050 23:59:59'] | Date: Checks if date lies in the specified range (both limits inclusive). Date format should be 'DD/MM/YYYY HH:mm:ss' | | isInteger | true (any boolean value) | Checks if number value is an integer | | default | "Narendra Modi" (any type of value) | Sets a default value to key if error encountered while validating this key | | strictObject | false (boolean) | If false, treats date/error/null/array as type 'object' (javascript native behaviour) |

Options with decsription

| Flag | Default Value | Description | |-----------|-----------|-------------| | matchPartialSchema | false | If true, checks only the keys present in object with that in schema | | strictMatch | false | If true, checks if object does not contain any extra keys than those mentioned in schema | | setDefaultValues | true | If false, does not set default value to a key even if default value is specified |

Contributions

You can add any of the above features into this package and create a pull request. For any further queries, write to [email protected]

Keywords

kasper object validation schema model external nodejs javascript typescript flow datatype type-validation json validator casper blueprint