node-helper-utilities

node-utilities

a generic utilities library for node.js

Installation

Install and use it via npm.

npm install limianwang/node-utilities#v1.5.0 --save

This will install the github repo @ tag v1.5.0.

Usage

Clone: Clone an object

var util = require('./');

var obj = {
  key: 'value',
  key2: {
    field : ['a','b']
  }
};

var cloned = util.clone(obj);

Merge: Merge two objects together

var util = require('./');

var a = {
  a: 'b'
};

var b = {
  b: 'c'
};

var out = util.merge(a, b);

Memoize: memoize function responses

var util = require('./');

function echo(i) {
  return i;
}

var cache = memoize(echo);

cache(1);
cache(1); // returns from cache

Cluster: Helper to start process in a cluster.

Takes optional config as follow:

{
  "enable": true,
  "instances": 5
}

By default, the instances is set to (Max CPUs - 1).

var util = require('./');
var http = require('http');

function start() {
  http.createServer(function(req, res) {}).listen(3000);
}
util.cluster(function() {
  // start server...
  start();
});

// Or using configs.

util.cluster(config, function() {
  // start server...
  start();
});

Token: Token creator

Create uniquely generated tokens.

var util = require('./');

util.unique()
  .then(function(token) {
    console.log(token);
  })
  .catch(function(err) {
    // some error happened;
    console.log(err);
  });

// or allow prefix.

util.unique('someprefix')
  .then(function(token) {
    console.log(token); // someprefix:<unique>
  })
  .catch(function(err) {
    assert(err);
  });

Encrypt Sensitive Information (using bcrypt)

var util = require('./');

util.hash('password')
  .then(function(hashed) {
    console.log(hashed);
  })
  .catch(function(err) {
    console.log(err);
  });
  
util.compare('password', hashed)
  .then(function(result) {
    console.log(result);
  })
  .catch(function(err) { 
    console.log(err); 
  });

Defer

Defer a function to a later time (default: 0 ms, ie. next iteration)

var util = require('./');

util.defer(100)
  .then(function() {
    console.log('this happened 100 ms later!');
  });

console.log('this happens immediately!');

Parse JSON

Often when you deal with async processes and have to pass data as JSON around, there is always potential for errors. This function is to parse json safely, and return a promise.

var util = require('./');
var couldBeJSONcouldBeString = ...;

util.parse(couldBeJSONcouldBeString)
  .then(function(parsed) {
    // parsed version of `couldBeJSONcouldBeString`
    console.log(parsed);
  })
  .catch(function(err) {
    // handle error here
    console.log(err);
  });

Read and Write File

var util = require('./');

var path = 'some_path';

util.write(path, 'hello world!')
  .then(function() {
    return util.read(path);
  })
  .then(function(data) {
    console.log(data); // hello world!
  })
  .catch(function(err) {
    console.log(err.stack);
  });

Tests

All tests are within tests.

Run tests using make test or make test-cov for test coverage.

TravisCI build is tested against:

• 0.10
• 0.11
• 0.12
• iojs (latest)