utils

Fast, generic JavaScript/node.js utility functions.

utils

Fast, generic JavaScript/node.js utility functions.

Why another utils lib?

  • I'm a node.js developer. I want fast, light, dependable utility functions for node.js projects.
  • Do you really need bloated, everything-but-the-kitchen-sink functions that are guaranteed to work with IE 4, for your Yeoman generator or gulp plugin!? Nonsense.
  • The benchmarks that accompany many of the functions in the library show that in some cases, the penalty for using such "kitchen-sink" code is a 2,000-5,000% reduction in speed. Sometimes greater.

Goals

  • Fastest implementation of each method, without too much compromise. Covering uncommon cases is fine, but don't go overboard.
  • Clean well-documented, commented code.
  • When it makes sense, external libraries are used and exposed instead of writing new code.
  • Focus on node.js usage and projects that are likely to use a number of these utils in one project. If you only need one or two of these in a small project, don't use this. Use small modules that do only one thing.

Install with npm

npm i utils --save

Utils grouped by collection

The top level export gives you an object with utils grouped into collections, like array, object, math, etc:

var utils = require('utils');
//=> {array: {flatten: [function], ...}, collection: {...}} 

See example.md for visual representation of the object.

Get all utils on one object

If you want all utils on a single object (e.g. not grouped by collection):

// all utils are on the `_` property 
var utils = require('utils')._;

Only get a specific collection

If you just want the string or object utils:

var string = require('utils').string;
var object = require('utils').object;

(The below API documentation is generated by [Verb]. )

.after

Returns all of the items in an array after the specified index.

  • array {Array}: Collection
  • n {Number}: Starting index (number of items to exclude)
  • returns {Array}: Array exluding n items.
after(['a', 'b', 'c'], 1)
//=> ['c'] 

.arrayify

Cast the give value to an array.

  • val {}*
  • returns: {Array}
arrayify('abc')
//=> ['abc'] 
 
arrayify(['abc'])
//=> ['abc'] 

.before

Returns all of the items in an array up to the specified number Opposite of <%= after() %.

  • array {Array}
  • n {Number}
  • returns {Array}: Array excluding items after the given number.
before(['a', 'b', 'c'], 2)
//=> ['a', 'b'] 

.compact

Remove all falsey values from an array.

  • arr {Array}
  • returns: {Array}
compact([null, a, , 0, false, b, c, '']);
//=> [a, b, c] 

.difference

Return the difference between the first array and additional arrays.

  • a {Array}
  • b {Array}
  • returns: {Array}
var a = ['a', 'b', 'c', 'd'];
var b = ['b', 'c'];
 
diff(a, b);
//=> ['a', 'd'] 

.first

Returns the first item, or first n items of an array.

  • array {Array}
  • n {Number}: Number of items to return, starting at 0.
  • returns: {Array}
first(['a', 'b', 'c', 'd', 'e'], 2)
//=> ['a', 'b'] 

.flatten

Recursively flatten an array or arrays. Uses the fastest implementation of array flatten for node.js

  • array {Array}
  • returns {Array}: Flattened array
flatten(['a', ['b', ['c']], 'd', ['e']]);
//=> ['a', 'b', 'c', 'd', 'e'] 

.forEach

Loop over each item in an array and call the given function on every element.

  • array {Array}
  • fn {Function}
  • thisArg {Object}: Optionally pass a thisArg to be used as the context in which to call the function.
  • returns: {Array}
forEach(['a', 'b', 'c'], function (ele) {
  return ele + ele;
});
//=> ['aa', 'bb', 'cc'] 
 
forEach(['a', 'b', 'c'], function (elei) {
  return i + ele;
});
//=> ['0a', '1b', '2c'] 

.isArray

Returns true if the given value is an array.

  • value {Array}: Value to test.
isArray(1);
//=> 'false' 
 
isArray([1]);
//=> 'true' 

.last

Returns the last item, or last n items of an array.

  • array {Array}
  • n {Number}: Number of items to return, starting with the last item.
  • returns: {Array}
last(['a', 'b', 'c', 'd', 'e'], 2)
//=> ['d', 'e'] 

.map

Returns a new array with the results of calling the given function on every element in the array. This is a faster, node.js focused alternative to JavaScript's native array map.

  • array {Array}
  • fn {Function}
  • returns: {Array}
map(['a', 'b', 'c'], function (ele) {
  return ele + ele;
});
//=> ['aa', 'bb', 'cc'] 
 
map(['a', 'b', 'c'], function (elei) {
  return i + ele;
});
//=> ['0a', '1b', '2c'] 

.union

Return an array free of duplicate values. Fastest ES5 implementation.

  • array {Array}: The array to uniquify
  • returns {Array}: With all union values.
union(['a', 'b', 'c', 'c']);
//=> ['a', 'b', 'c'] 

.unique

Return an array free of duplicate values. Fastest ES5 implementation.

  • array {Array}: The array to uniquify
  • returns {Array}: With all unique values.
unique(['a', 'b', 'c', 'c']);
//=> ['a', 'b', 'c'] 

.any

  • value {}*
  • target {}*
  • options {Object}

Returns true if value exists in the given string, array or object. See [any] for documentation.

.contains

  • collection {Array|Object}
  • string {}*
  • returns: {Boolean}

Return true if collection contains value

.tryReaddir

  • dir {String}: Starting directory
  • returns {Array}: Array of files.

Try to read the given directory. Wraps fs.readdirSync() with a try/catch, so it fails silently instead of throwing when the directory doesn't exist.

.tryRequire

  • fp {String}: File path of the file to require
  • returns {}*: Returns the module function/object, or null if not found.

Try to require the given file, returning null if not successful instead of throwing an error.

.hasValues

Returns true if any value exists, false if empty. Works for booleans, functions, numbers, strings, nulls, objects and arrays.

  • object {Object}: The object to check for value
  • value {}*: the value to look for
  • returns {Boolean}: True if any values exists.
utils.lang.hasValues('a');
//=> true 
 
utils.lang.hasValues('');
//=> false 
 
utils.lang.hasValues(1);
//=> true 
 
utils.lang.hasValues({a: 'a'}});
//=> true 
 
utils.lang.hasValues({}});
//=> false 
 
utils.lang.hasValues(['a']);
//=> true 

.isEmpty

Returns true if the given value is empty, false if any value exists. Works for booleans, functions, numbers, strings, nulls, objects and arrays.

  • object {Object}: The object to check for value
  • value {}*: the value to look for
  • returns {Boolean}: False if any values exists.
utils.lang.isEmpty('a');
//=> true 
 
utils.lang.isEmpty('');
//=> false 
 
utils.lang.isEmpty(1);
//=> true 
 
utils.lang.isEmpty({a: 'a'}});
//=> true 
 
utils.lang.isEmpty({}});
//=> false 
 
utils.lang.isEmpty(['a']);
//=> true 

.isObject

Return true if the given value is an object with keys.

  • value {Object}: The value to check.
  • returns: {Boolean}
isObject(['a', 'b', 'c'])
//=> 'false' 
 
isObject({a: 'b'})
//=> 'true' 

.isPlainObject

Return true if the given value is an object with keys.

  • value {Object}: The value to check.
  • returns: {Boolean}
isPlainObject(Object.create({}));
//=> true 
isPlainObject(Object.create(Object.prototype));
//=> true 
isPlainObject({foo: 'bar'});
//=> true 
isPlainObject({});
//=> true 

.sum

Returns the sum of all numbers in the given array.

  • array {Array}: Array of numbers to add up.
  • returns: {Number}
sum([1, 2, 3, 4, 5])
//=> '15' 

.extend

  • o {Object}: The target object. Pass an empty object to shallow clone.
  • objects {Object}
  • returns: {Object}

Extend o with properties of other objects.

.functions

Returns a copy of the given obj filtered to have only enumerable properties that have function values.

  • obj {Object}
  • returns: {Object}
functions({a: 'b'c: function() {}});
//=> {c: function() {}} 

.hasOwn

Return true if key is an own, enumerable property of the given obj.

  • key {String}
  • obj {Object}: Optionally pass an object to check.
  • returns: {Boolean}
hasOwn(obj, key);

.keys

  • obj {Object}
  • returns {Array}: Array of keys.

Return an array of keys for the given obj. Uses Object.keys when available, otherwise falls back on forOwn.

merge

  • o {Object}: The target object. Pass an empty object to shallow clone.
  • objects {Object}
  • returns: {Object}

Recursively combine the properties of o with the properties of other objects.

.methods

  • obj {Object}
  • returns: {Array}

Returns a list of all enumerable properties of obj that have function values

.camelcase

camelCase the characters in string.

  • string {String}: The string to camelcase.
  • returns: {String}
camelcase("foo bar baz");
//=> 'fooBarBaz' 

.centerAlign

Center align the characters in a string using non-breaking spaces.

  • str {String}: The string to reverse.
  • returns {String}: Centered string.
centerAlign("abc");

.chop

Like trim, but removes both extraneous whitespace and non-word characters from the beginning and end of a string.

  • string {String}: The string to chop.
  • returns: {String}
chop("_ABC_");
//=> 'ABC' 
 
chop("-ABC-");
//=> 'ABC' 
 
chop(" ABC ");
//=> 'ABC' 

.count

Count the number of occurrances of a substring within a string.

  • string {String}
  • substring {String}
  • returns {Number}: The occurances of substring in string
count("abcabcabc", "a");
//=> '3' 

.dashcase

dash-case the characters in string. This is similar to [slugify], but [slugify] makes the string compatible to be used as a URL slug.

  • string {String}
  • returns: {String}
dashcase("a b.c d_e");
//=> 'a-b-c-d-e' 

.dotcase

dot.case the characters in string.

  • string {String}
  • returns: {String}
dotcase("a-b-c d_e");
//=> 'a.b.c.d.e' 

.ellipsis

Truncate a string to the specified length, and append it with an elipsis, .

  • str {String}
  • length {Number}: The desired length of the returned string.
  • ch {String}: Optionally pass custom characters to append. Default is .
  • returns {String}: The truncated string.
ellipsis("<span>foo bar baz</span>", 7);
//=> 'foo bar…' 

.hyphenate

Replace spaces in a string with hyphens. This

  • string {String}
  • returns: {String}
hyphenate("a b c");
//=> 'a-b-c' 

.isString

Returns true if the value is a string.

  • val {String}
  • returns {Boolean}: True if the value is a string.
isString('abc');
//=> 'true' 
 
isString(null);
//=> 'false' 

.pascalcase

PascalCase the characters in string.

  • string {String}
  • returns: {String}
pascalcase("foo bar baz");
//=> 'FooBarBaz' 

.pathcase

path/case the characters in string.

  • string {String}
  • returns: {String}
pathcase("a-b-c d_e");
//=> 'a/b/c/d/e' 

.replace

Replace occurrences of a with b.

  • str {String}
  • a {String|RegExp}: Can be a string or regexp.
  • b {String}
  • returns: {String}
replace("abcabc", /a/, "z");
//=> 'zbczbc' 

.reverse

Reverse the characters in a string.

  • str {String}: The string to reverse.
  • returns: {String}
reverse("abc");
//=> 'cba' 

.rightAlign

Right align the characters in a string using non-breaking spaces.

  • str {String}: The string to reverse.
  • returns {String}: Right-aligned string.
rightAlign(str);

.sentencecase

Sentence-case the characters in string.

  • string {String}
  • returns: {String}
sentencecase("foo bar baz.");
//=> 'Foo bar baz.' 

.snakecase

snake_case the characters in string.

  • string {String}
  • returns: {String}
snakecase("a-b-c d_e");
//=> 'a_b_c_d_e' 

.truncate

Truncate a string by removing all HTML tags and limiting the result to the specified length.

  • str {String}
  • length {Number}: The desired length of the returned string.
  • returns {String}: The truncated string.
truncate("<span>foo bar baz</span>", 7);
//=> 'foo bar' 

.wordwrap

Wrap words to a specified width using [word-wrap].

  • string {String}: The string with words to wrap.
  • object {Options}: Options to pass to [word-wrap]
  • returns {String}: Formatted string.
wordwrap("a b c d e f", {width: 5, newline: '<br>  '});
//=> '  a b c <br>  d e f' 

Please help improve code coverage by adding unit tests.

-----------------------|-----------|-----------|-----------|-----------|
File                   |   % Stmts |% Branches |   % Funcs |   % Lines |
-----------------------|-----------|-----------|-----------|-----------|
   array/              |     76.24 |     67.19 |     85.71 |     77.32 |
      after.js         |       100 |        75 |       100 |       100 |
      arrayify.js      |       100 |       100 |       100 |       100 |
      before.js        |       100 |        75 |       100 |       100 |
      compact.js       |       100 |       100 |       100 |       100 |
      difference.js    |       100 |       100 |       100 |       100 |
      first.js         |     88.89 |     83.33 |       100 |     88.24 |
      flatten.js       |       100 |       100 |       100 |       100 |
      forEach.js       |      12.5 |         0 |         0 |     14.29 |
      indexOf.js       |      7.69 |         0 |         0 |      8.33 |
      isArray.js       |       100 |       100 |       100 |       100 |
      last.js          |     88.89 |     83.33 |       100 |     88.24 |
      map.js           |       100 |       100 |       100 |       100 |
      sort.js          |     90.91 |      87.5 |       100 |     90.91 |
      union.js         |       100 |       100 |       100 |       100 |
      unique.js        |       100 |       100 |       100 |       100 |
   collection/         |        50 |         0 |         0 |        50 |
      any.js           |       100 |       100 |       100 |       100 |
      contains.js      |     42.86 |         0 |         0 |     42.86 |
   fs/                 |        80 |       100 |       100 |        80 |
      tryReaddir.js    |        80 |       100 |       100 |        80 |
      tryRequire.js    |        80 |       100 |       100 |        80 |
   lang/               |      87.5 |       100 |        50 |      87.5 |
      hasValues.js     |       100 |       100 |       100 |       100 |
      isEmpty.js       |     66.67 |       100 |         0 |     66.67 |
      isObject.js      |       100 |       100 |       100 |       100 |
      isPlainObject.js |       100 |       100 |       100 |       100 |
   math/               |       100 |       100 |       100 |       100 |
      sum.js           |       100 |       100 |       100 |       100 |
   object/             |     69.57 |     54.55 |     27.27 |     68.66 |
      extend.js        |       100 |     83.33 |       100 |       100 |
      filter.js        |       100 |       100 |       100 |       100 |
      forIn.js         |       100 |       100 |       100 |       100 |
      forOwn.js        |       100 |       100 |       100 |       100 |
      functions.js     |     28.57 |         0 |         0 |     28.57 |
      hasOwn.js        |       100 |       100 |       100 |       100 |
      keys.js          |     33.33 |        50 |         0 |     33.33 |
      merge.js         |       100 |        75 |       100 |       100 |
      methods.js       |     28.57 |         0 |         0 |     28.57 |
      omit.js          |       100 |       100 |       100 |       100 |
      pick.js          |       100 |       100 |       100 |       100 |
      reduce.js        |       100 |       100 |       100 |       100 |
      some.js          |        30 |         0 |         0 |        30 |
   string/             |     99.27 |     96.77 |        96 |     99.09 |
      camelcase.js     |       100 |       100 |       100 |       100 |
      centerAlign.js   |       100 |       100 |       100 |       100 |
      chop.js          |       100 |       100 |       100 |       100 |
      count.js         |       100 |       100 |       100 |       100 |
      dashcase.js      |       100 |       100 |       100 |       100 |
      dotcase.js       |       100 |       100 |       100 |       100 |
      ellipsis.js      |       100 |       100 |       100 |       100 |
      hyphenate.js     |       100 |       100 |       100 |       100 |
      index.js         |       100 |       100 |       100 |       100 |
      isString.js      |       100 |       100 |       100 |       100 |
      pascalcase.js    |       100 |       100 |       100 |       100 |
      pathcase.js      |       100 |       100 |       100 |       100 |
      replace.js       |       100 |       100 |       100 |       100 |
      reverse.js       |       100 |       100 |       100 |       100 |
      rightAlign.js    |       100 |       100 |       100 |       100 |
      sentencecase.js  |       100 |       100 |       100 |       100 |
      slugify.js       |       100 |       100 |       100 |       100 |
      snakecase.js     |       100 |       100 |       100 |       100 |
      toString.js      |        50 |         0 |         0 |        50 |
      truncate.js      |       100 |       100 |       100 |       100 |
      wordwrap.js      |       100 |       100 |       100 |       100 |
-----------------------|-----------|-----------|-----------|-----------|
All files              |     84.55 |     77.27 |     75.44 |     83.55 |
-----------------------|-----------|-----------|-----------|-----------|
 

Install dev dependencies.

npm i -d && npm test

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue

If you want to do a PR to add a util, please read the following first:

  • follow the same coding style as the rest of the library, same with code comments
  • add sufficient unit tests
  • Install dev dependencies and run verb
  • Look over the README to make sure that verb rendered out the docs with your method and code comments.

Adding external modules as dependencies

  • External modules will only be considered if they meet the same quality and coding standards as the rest of the library. At minimum this includes documentation, code comments, and unit tests. Benchmarks are also strongly preferred.

Do not edit the readme manually since [verb] is used to generate documentation.

  • API docs: If you see an error in the API documentation, just update the code comments for that method, then run verb.
  • Everything else, please look over the .verb.md template to see where the error is, then run verb.

Run [verb] to generate documentation:

npm i -&& verb

Jon Schlinkert

Copyright (c) 2015 Jon Schlinkert
Released under the MIT license