decorate-it

decorate-it

Decorate-it is a simple library for validation and logging.
It depends on joi (validator) and bunyan (logger)

Installation

npm i --save decorate-it

Sample usage

file services/CalcService.js

import Joi from 'joi';
import decorate from 'decorate-it';

function add(a, b) {
  return a + b;
}

add.sync = true;
add.schema = {
  a: Joi.number().required(),
  b: Joi.number().required(),
};


// create your service
const CalcService = {
  add,
};

// decorate it, it will mutate CalcService
decorate(CalcService, 'CalcService');

export default CalcService;

use service

import CalcService from './services/CalcService';


CalcService.add(1, 3); // returns 4
CalcService.add('5', '6'); // returns 11, input parameters are converted to number types
CalcService.add('1', { foo: 'bar' }); // logs and throws an error

See example under example/example1.js. Run it using npm run example1.

Async sample usage

file services/UserService.js

import Joi from 'joi';
import decorate from 'decorate-it';

async function getUser(id) {
  if (id === 1) {
    return await new Promise((resolve) => {
      setTimeout(() => resolve({ id: 1, username: 'john' }), 100);
    });
  }
  throw new Error('User not found');
}
getUser.sync = false; // optional, false by default
getUser.params = ['id'];
getUser.schema = {
  id: Joi.number().required(),
};


// create your service
const UserService = {
  getUser,
};

// decorate it, it will mutate UserService
decorate(UserService, 'UserService');

export default UserService;

use service

import UserService from './services/UserService';


await UserService.getUser(1); // returns { id: 1, username: 'john' }
await UserService.getUser(222); // throws 'User not found'

See example under example/example2.js. Run it using npm run example2.
NOTE parameter names cannot be automatically retrieved from async methods.
You must define them explicitly in params property like this getUser.params = ['id'];

Removing security information

By default properties password, token, accessToken are removed from logging.
Additionally you can define removeOutput = true to remove the method result.
Example:

file services/SecurityService.js

import Joi from 'joi';
import decorate from 'decorate-it';

function hashPassword(password) {
  return 'ba817ef716'; // hash password here
}

hashPassword.removeOutput = true;
hashPassword.schema = {
  password: Joi.string().required(),
};


// create your service
const SecurityService = {
  hashPassword,
};

// decorate it, it will mutate SecurityService
decorate(SecurityService, 'SecurityService');

export default SecurityService;

use service

import SecurityService from './services/SecurityService';

SecurityService.hashPassword('secret-password');

See example under example/example3.js. Run it using npm run example3.

Configuration

import decorate from 'decorate-it';

decorate.configure({
  removeFields: Array<String>, // the array of fields not won't be logged to the console, default: ['password', 'token', 'accessToken'],
  debug: true/false,           // the flag is parameter/ouput logging is enabled, (errors are always enabled), default: true
  depth: number,               // the object depth level when serializing, default: 4           
  maxArrayLength: number,      // the maximum number of elements to include when formatting an array, default: 30  
})

You must configure it, before creating any service.

Special properties

if the parameter name is req it's assumed that the object is an express request.
Only properties are logged: method, url, headers, remoteAddress, remotePort.

if the parameter name is res it's assumed that the object is an express response.
Only properties are logged: statusCode, header.

MIT License

Copyright (c) 2016 Łukasz Sentkiewicz