utils  

> Fast, generic JavaScript/node.js utility functions.

Install with npm

``sh
$ npm i utils --save
`

TOC

* Usage
* API
* Code coverage
* Running tests
* Contributing
- Adding utils
- Updating the docs
- Running verb
* About
* Related projects
* Author
* License

_(Table of contents generated by verb)_

Usage

Utils grouped by collection

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

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

See example.md for an example of the utils object.

Get all utils on one object

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

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

Only get a specific collection

If you just want the string or object utils:

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

API

$3

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

Params

* array {Array}: Collection
* n {Number}: Starting index (number of items to exclude)
* returns {Array}: Array exluding n items.

Example

`js
after(['a', 'b', 'c'], 1)
//=> ['c']
`

$3

Cast the give value to an array.

Params

val {}
* returns {Array}

Example

`js
arrayify('abc')
//=> ['abc']

arrayify(['abc'])
//=> ['abc']
`

$3

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

Params

* array {Array}
* n {Number}
* returns {Array}: Array excluding items after the given number.

Example

`js
before(['a', 'b', 'c'], 2)
//=> ['a', 'b']
`

$3

Remove all falsey values from an array.

Params

* arr {Array}
* returns {Array}

Example

`js
compact([null, a, undefined, 0, false, b, c, '']);
//=> [a, b, c]
`

$3

Return the difference between the first array and additional arrays.

Params

* a {Array}
* b {Array}
* returns {Array}

Example

`js
var a = ['a', 'b', 'c', 'd'];
var b = ['b', 'c'];

diff(a, b);
//=> ['a', 'd']
`

$3

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

Params

* array {Array}
* fn {Function}
* thisArg {Object}: Optionally pass a thisArg to be used as the context in which to call the function.
* returns {Array}

Example

`js
each(['a', 'b', 'c'], function (ele) {
return ele + ele;
});
//=> ['aa', 'bb', 'cc']

each(['a', 'b', 'c'], function (ele, i) {
return i + ele;
});
//=> ['0a', '1b', '2c']
`

$3

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

Params

* array {Array}
* n {Number}: Number of items to return, starting at 0.
* returns {Array}

Example

`js
first(['a', 'b', 'c', 'd', 'e'], 2)
//=> ['a', 'b']
`

$3

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

Params

* array {Array}
* returns {Array}: Flattened array

Example

`js
flatten(['a', ['b', ['c']], 'd', ['e']]);
//=> ['a', 'b', 'c', 'd', 'e']
`

$3

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

Params

* array {Array}
* fn {Function}
* thisArg {Object}: Optionally pass a thisArg to be used as the context in which to call the function.
* returns {Array}

Example

`js
forEach(['a', 'b', 'c'], function (ele) {
return ele + ele;
});
//=> ['aa', 'bb', 'cc']

forEach(['a', 'b', 'c'], function (ele, i) {
return i + ele;
});
//=> ['0a', '1b', '2c']
`

$3

Returns true if the given value is an array.

Params

* value {Array}: Value to test.

Example

`js
isArray(1);
//=> 'false'

isArray([1]);
//=> 'true'
`

$3

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

Params

* array {Array}
* n {Number}: Number of items to return, starting with the last item.
* returns {Array}

Example

`js
last(['a', 'b', 'c', 'd', 'e'], 2)
//=> ['d', 'e']
`

$3

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.

Params

* array {Array}
* fn {Function}
* returns {Array}

Example

`js
map(['a', 'b', 'c'], function (ele) {
return ele + ele;
});
//=> ['aa', 'bb', 'cc']

map(['a', 'b', 'c'], function (ele, i) {
return i + ele;
});
//=> ['0a', '1b', '2c']
`

$3

Alternative to JavaScript's native array-slice method. Slices array from the start index up to but not including the end index.

Params

* array {Array}: the array to slice.
* start {Number}: Optionally define the starting index.
* end {Number}: Optionally define the ending index.

Example

`js
var arr = ['a', 'b', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];

slice(arr, 3, 6);
//=> ['e', 'f', 'g']
`

$3

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

Params

* array {Array}: The array to uniquify
* returns {Array}: With all union values.

Example

`js
union(['a', 'b', 'c', 'c']);
//=> ['a', 'b', 'c']
`

$3

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

Params

* array {Array}: The array to uniquify
* returns {Array}: With all unique values.

Example

`js
unique(['a', 'b', 'c', 'c']);
//=> ['a', 'b', 'c']
`

$3

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

Params

value {}
target {}
* options {Object}

$3

Return true if collection contains value

Params

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

$3

Try to read the given filepath, fail silently and return null
when a file doesn't exist. Slightly faster than using fs.existsSync.

Params

* fp {String}: Path of the file to read.
* returns {String|Null}: the utf8 contents string, or null if an error is thrown.

$3

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.

Params

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

$3

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

Params

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

$3

Returns the first argument passed to the function.

returns {}

$3

A "no-operation" function. Returns undefined regardless
of the arguments it receives.

* returns {undefined}

$3

Partially applies arguments that will be appended to those provided to the returned function.

Params

* ctx {Object}: Optionally supply an invocation context for the returned function.
* fn {Function}: The function to which arguments should be partially applied.
arguments __{..._}_: List of arguments to be partially applied.
* returns {Function}: Returns a function with partially applied arguments.

Example

`js
function fullname(first, last) {
return first + ' ' + last;
}

var name = partialRight(fn, 'Woodward');
name('Brian');
//=> 'Brian Woodward'
`

$3

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

Params

* object {Object}: The object to check for value
value {}: the value to look for
* returns {Boolean}: True if any values exists.

Example

`js
hasValues('a');
//=> true

hasValues('');
//=> false

hasValues(1);
//=> true

hasValues({a: 'a'}});
//=> true

hasValues({}});
//=> false

hasValues(['a']);
//=> true
`

$3

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

Params

* object {Object}: The object to check for value
value {}: the value to look for
* returns {Boolean}: False if any values exists.

Example

`js
isEmpty('a');
//=> false

isEmpty('');
//=> true

isEmpty(1);
//=> false

isEmpty({a: 'a'});
//=> false

isEmpty({});
//=> true

isEmpty(['a']);
//=> false
`

$3

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

Params

* value {Object}: The value to check.
* returns {Boolean}

Example

`js
isObject(['a', 'b', 'c'])
//=> 'false'

isObject({a: 'b'})
//=> 'true'
`

$3

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

Params

* value {Object}: The value to check.
* returns {Boolean}

Example

`js
isPlainObject(Object.create({}));
//=> true
isPlainObject(Object.create(Object.prototype));
//=> true
isPlainObject({foo: 'bar'});
//=> true
isPlainObject({});
//=> true
`

$3

Returns the sum of all numbers in the given array.

Params

* array {Array}: Array of numbers to add up.
* returns {Number}

Example

`js
sum([1, 2, 3, 4, 5])
//=> '15'
`

$3

Extend object with properties of other objects

Params

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

$3

Extend o with properties of other objects.

Params

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

$3

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

Params

* obj {Object}
* returns {Object}

Example

`js
functions({a: 'b', c: function() {}});
//=> {c: function() {}}
`

$3

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

Params

* key {String}
* obj {Object}: Optionally pass an object to check.
* returns {Boolean}

Example

`js
hasOwn(obj, key);
`

$3

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

Params

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

$3

Returns new object where each value is the result of
calling the a callback function.

Params

* {Object}: obj The object to iterate over
* cb {Function}: Callback function
* {Object}: thisArg Invocation context of cb
* returns {Object}

$3

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

Params

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

$3

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

Params

* obj {Object}
* returns {Array}

$3

Reduces an object to a value that is the accumulated result of running each property in the object through a callback.

Params

* obj {Object}: The object to iterate over.
* iterator {Function}: Iterator function
* initial {Object}: Initial value.
* thisArg {Object}: The this binding of the iterator function.
* returns {Object}

Example

`js
var a = {a: 'foo', b: 'bar', c: 'baz'};

reduce(a, function (acc, value, key, obj) {
// acc- the initial value (or value from the previous callback call),
// value- the of the current property,
// key- the of the current property, and
// obj - original object

acc[key] = value.toUpperCase();
return acc;
}, {});

//=> {a: 'FOO', b: 'BAR', c: 'BAZ'};
`

$3

camelCase the characters in string.

Params

* string {String}: The string to camelcase.
* returns {String}

Example

`js
camelcase("foo bar baz");
//=> 'fooBarBaz'
`

$3

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

Params

* str {String}: The string to reverse.
* returns {String}: Centered string.

Example

`js
centerAlign("abc");
`

$3

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

Params

* string {String}: The string to chop.
* returns {String}

Example

`js
chop("_ABC_");
//=> 'ABC'

chop("-ABC-");
//=> 'ABC'

chop(" ABC ");
//=> 'ABC'
`

$3

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

Params

* string {String}
* substring {String}
* returns {Number}: The occurances of substring in string

Example

`js
count("abcabcabc", "a");
//=> '3'
`

$3

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

Params

* string {String}
* returns {String}

Example

`js
dashcase("a b.c d_e");
//=> 'a-b-c-d-e'
`

$3

dot.case the characters in string.

Params

* string {String}
* returns {String}

Example

`js
dotcase("a-b-c d_e");
//=> 'a.b.c.d.e'
`

$3

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

Params

* 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.

Example

`js
ellipsis("foo bar baz", 7);
//=> 'foo bar…'
`

$3

Replace spaces in a string with hyphens. This

Params

* string {String}
* returns {String}

Example

`js
hyphenate("a b c");
//=> 'a-b-c'
`

$3

Returns true if the value is a string.

Params

* val {String}
* returns {Boolean}: True if the value is a string.

Example

`js
isString('abc');
//=> 'true'

isString(null);
//=> 'false'
`

$3

PascalCase the characters in string.

Params

* string {String}
* returns {String}

Example

`js
pascalcase("foo bar baz");
//=> 'FooBarBaz'
`

$3

path/case the characters in string.

Params

* string {String}
* returns {String}

Example

`js
pathcase("a-b-c d_e");
//=> 'a/b/c/d/e'
`

$3

Replace occurrences of a with b.

Params

* str {String}
* a {String|RegExp}: Can be a string or regexp.
* b {String}
* returns {String}

Example

`js
replace("abcabc", /a/, "z");
//=> 'zbczbc'
`

$3

Reverse the characters in a string.

Params

* str {String}: The string to reverse.
* returns {String}

Example

`js
reverse("abc");
//=> 'cba'
`

$3

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

Params

* str {String}: The string to reverse.
* returns {String}: Right-aligned string.

Example

`js
rightAlign(str);
`

$3

Sentence-case the characters in string.

Params

* string {String}
* returns {String}

Example

`js
sentencecase("foo bar baz.");
//=> 'Foo bar baz.'
`

$3

snake_case the characters in string.

Params

* string {String}
* returns {String}

Example

`js
snakecase("a-b-c d_e");
//=> 'a_b_c_d_e'
`

$3

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

Params

* str {String}
* length {Number}: The desired length of the returned string.
* returns {String}: The truncated string.

Example

`js
truncate("foo bar baz", 7);
//=> 'foo bar'
`

$3

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

Params

* string {String}: The string with words to wrap.
* object {Options}: Options to pass to [word-wrap]
* returns {String}: Formatted string.

Example

`js
wordwrap("a b c d e f", {width: 5, newline: '
'});
//=> ' a b c
d e f'
`

Code coverage

Please help improve code coverage by adding unit tests.

`
-----------------------|----------|----------|----------|----------|----------------|
File | % Stmts | % Branch | % Funcs | % Lines |Uncovered Lines |
-----------------------|----------|----------|----------|----------|----------------|
utils/ | 100 | 100 | 100 | 100 | |
index.js | 100 | 100 | 100 | 100 | |
utils/lib/ | 100 | 100 | 100 | 100 | |
index.js | 100 | 100 | 100 | 100 | |
utils/lib/array/ | 91.75 | 83.33 | 100 | 92.55 | |
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 | |
each.js | 100 | 100 | 100 | 100 | |
first.js | 88.89 | 83.33 | 100 | 88.24 | 27,46 |
flatten.js | 100 | 100 | 100 | 100 | |
forEach.js | 100 | 100 | 100 | 100 | |
index.js | 100 | 100 | 100 | 100 | |
indexOf.js | 76.92 | 70 | 100 | 83.33 | 23,40 |
isArray.js | 100 | 100 | 100 | 100 | |
last.js | 88.89 | 83.33 | 100 | 88.24 | 27,46 |
map.js | 100 | 100 | 100 | 100 | |
slice.js | 100 | 100 | 100 | 100 | |
sort.js | 90.91 | 87.5 | 100 | 90.91 | 27 |
union.js | 100 | 100 | 100 | 100 | |
unique.js | 100 | 100 | 100 | 100 | |
utils/lib/collection/ | 55.56 | 0 | 0 | 55.56 | |
any.js | 100 | 100 | 100 | 100 | |
contains.js | 42.86 | 0 | 0 | 42.86 | 18,19,21,22 |
index.js | 100 | 100 | 100 | 100 | |
utils/lib/fs/ | 68.75 | 100 | 66.67 | 68.75 | |
index.js | 100 | 100 | 100 | 100 | |
tryRead.js | 40 | 100 | 0 | 40 | 16,17,19 |
tryReaddir.js | 80 | 100 | 100 | 80 | 20 |
tryRequire.js | 80 | 100 | 100 | 80 | 19 |
utils/lib/function/ | 36.36 | 0 | 0 | 36.36 | |
identity.js | 50 | 100 | 0 | 50 | 12 |
index.js | 100 | 100 | 100 | 100 | |
noop.js | 50 | 100 | 0 | 50 | 13 |
partialRight.js | 16.67 | 0 | 0 | 16.67 | 26,27,28,29,30 |
utils/lib/lang/ | 100 | 100 | 100 | 100 | |
hasValues.js | 100 | 100 | 100 | 100 | |
index.js | 100 | 100 | 100 | 100 | |
isEmpty.js | 100 | 100 | 100 | 100 | |
isObject.js | 100 | 100 | 100 | 100 | |
isPlainObject.js | 100 | 100 | 100 | 100 | |
typeOf.js | 100 | 100 | 100 | 100 | |
utils/lib/math/ | 100 | 100 | 100 | 100 | |
index.js | 100 | 100 | 100 | 100 | |
sum.js | 100 | 100 | 100 | 100 | |
utils/lib/object/ | 62.77 | 46.15 | 17.65 | 61.96 | |
defaults.js | 100 | 100 | 100 | 100 | |
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 | 21,23,24,25,29 |
hasOwn.js | 100 | 100 | 100 | 100 | |
index.js | 100 | 100 | 100 | 100 | |
keys.js | 33.33 | 50 | 0 | 33.33 | 16,17,18,20 |
mapValues.js | 37.5 | 100 | 0 | 37.5 | 18,19,21,22,25 |
merge.js | 100 | 75 | 100 | 100 | |
methods.js | 28.57 | 0 | 0 | 28.57 | 16,18,19,20,24 |
omit.js | 100 | 100 | 100 | 100 | |
pick.js | 100 | 100 | 100 | 100 | |
pluck.js | 75 | 100 | 0 | 75 | 17 |
prop.js | 33.33 | 100 | 0 | 33.33 | 4,5 |
reduce.js | 100 | 100 | 100 | 100 | |
result.js | 25 | 0 | 0 | 25 | 6,7,8,10,11,13 |
some.js | 30 | 0 | 0 | 30 |... 11,12,13,16 |
utils/lib/string/ | 99.28 | 96.77 | 96 | 99.1 | |
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 | 10 |
truncate.js | 100 | 100 | 100 | 100 | |
wordwrap.js | 100 | 100 | 100 | 100 | |
-----------------------|----------|----------|----------|----------|----------------|
All files | 84.54 | 80.52 | 67.16 | 83.43 | |
-----------------------|----------|----------|----------|----------|----------------|
`

Running tests

Install dev dependencies:

`sh
$ npm i -d && npm test
`

Contributing

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

$3

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.

$3

Do not edit the readme manually since verbis 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.

$3

Install dev dependencies, then run verb:

`js
$ npm install -d && verb
`

About

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.

Project 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.

Related projects

> This project depends on these great libraries. If you don't need a full utility belt for your project, any of these can be used by themselves:

* any: Returns true if a value exists in the given string, array or object. | homepage
* arr-diff: Returns an array with only the unique values from the first array, by excluding all… more | homepage
* arr-flatten: Recursively flatten an array or arrays. This is the fastest implementation of array flatten. | homepage
* arr-map: Faster, node.js focused alternative to JavaScript's native array map. | homepage
* arr-union: Combines a list of arrays, returning a single array with unique values, using strict equality… more | homepage
* array-each: Loop over each item in an array and call the given function on every element. | homepage
* array-slice: Array-slice method. Slices array from the start index up to, but not including, the end… more | homepage
* array-unique: Return an array free of duplicate values. Fastest ES5 implementation. | homepage
* center-align: Center-align the text in a string. | homepage
* export-dirs: Export directories and their files as node.js modules. | homepage
* export-files: node.js utility for exporting a directory of files as modules. | homepage
* for-in: Iterate over the own and inherited enumerable properties of an objecte, and return an object… more | homepage
* for-own: Iterate over the own enumerable properties of an object, and return an object with properties… more | homepage
* has-values: Returns true if any values exist, false if empty. Works for booleans, functions, numbers, strings,… more | homepage
* is-number: Returns true if the value is a number. comprehensive tests. | homepage
* is-plain-object: Returns true if an object was created by the Object constructor. | homepage
* kind-of: Get the native type of a value. | homepage
* make-iterator: Convert an argument into a valid iterator. Based on the .makeIterator() implementation in mout https://github.com/mout/mout. | homepage
* object.defaults: Like extend but only copies missing properties/values to the target object. | homepage
* object.filter: Create a new object filtered to have only properties for which the callback returns true. | homepage
* object.omit: Return a copy of an object excluding the given key, or array of keys. Also… more | homepage
* object.pick: Returns a filtered copy of an object with only the specified keys, like pick` from… more | homepage
* object.reduce: Reduces an object to a value that is the accumulated result of running each property… more | homepage
* right-align: Right-align the text in a string. | homepage
* striptags: PHP strip_tags in Node.js | homepage
* word-wrap: Wrap words to a specified length. | homepage

Author

Jon Schlinkert

+ github/jonschlinkert
+ twitter/jonschlinkert

License

Copyright © 2015 Jon Schlinkert
Released under the MIT license.

*

_This file was generated by verb-cli on September 23, 2015._