simplejsonvalidator v2.0.2

SimpleJsonValidator

Json Validator for NodeJS with simple ruby-like syntax

Installation

You can install this library using npm:

npm i --save simplejsonvalidator

Usage

First, you need to create a new JsonValidator instance calling to the exported function:

const jsonValidator = require('simplejsonvalidator');
const validator = jsonValidator();

Then, you can create validators using the 'create' method, which accepts a callback and the validator name

validator.create(t => ({
  user: t.string.required,  
  age: t.number,
  text: t.string.max(10).required,
}), 'validatorName');

or you can omit the validator name and assign the returning validator to a variable:

const myValidator = validator.create(t => ({
  user: t.string.required,  
  age: t.number,
  text: t.string.max(10).required,
}));

Finally, you can validate any json using the 'validate' function:

const json = {
  user: 'user',  
  age: 22,
  text: '123456789',
};
myValidator.validate(json);

You can also nest objects like this:

const demoValidator = validator.create(t => ({
  user: t.string.required,
  age: t.number,
  text: t.string.max(10).required,
  data: {
    token: t.string,
  },
}));

And you can check why a json is invalid:

const errors = demoValidator.errors();

Errors look like these:

[
  {
    message: 'element "key" must be string',
    type: 'string',
  },
  {
    message: 'key "user.name" should be upper than 10',
    type: 'string',
  },
  {
    message: 'key "user.age" should be positive',
    type: 'number',
  },
  {
    message: 'element "user.connection" must be date',
    type: 'date',
  },
]

Types

String

Validates if type is string. Example:

validator.create(t => ({
  key: t.string,
}));

You can use these validators in string type:

Number

Validates if type is number. Example:

validator.create(t => ({
  key: t.number,
}));

You can use these validators in number type:

Boolean

Validates if type is boolean. Example:

validator.create(t => ({
  key: t.boolean,
}));

You can use these validators in boolean type:

Array

Validates if type is array. Example:

validator.create(t => ({
  key: t.array,
}));

You can use these validators in array type:

Date

Validates if type is date. Example:

validator.create(t => ({
  key: t.date,
}));

You can use these validators in date type:

Express Framework Integration

You can use an express middleware to check jsons. You can do it calling to createMiddleware function to create a middleware:

const myValidator = validator.create(t => ({
  user: t.string.required,  
  age: t.number,
  text: t.string.max(10).required,
}));

app.post('/', validator.createMiddleware(myValidator), (req, res) => res.send(req.body););

The middleware, when a json is not valid, returns found errors. You can customize the returning status code:

const middleware = validator.createMiddleware(myValidator, 401);