@mentoc/utils NPM

js-utils

A collection of composable utility functions. Take what you need, and uninstall the library. No more bloated utility libraries. Did I mention, I added a minify step?

Motivation

I feel like there are bits of functionality that I need to use everyday in my javascript projects. All the functionality I'm looking for isn't there or is inside another npm package. I solved the npm portion by allowing developers the option to extract only specific functions. This makes it so that developers are no longer tied to an NPM repo. Take the functions you need and uninstall the library.

Installation

npm install @mentoc/utils

Before you copy and paste!

Did you know, this library can export only the functions you need? Let's say we only want the random_array and shuffle functions. Easy. All we have to do is run this:

npm run pluck rand.random_array rand.shuffle

Now if you do an ls, you will notice that there is now a lib.js file. If you look at the contents of lib.js, you'll notice it only contains two exports (for both of the functions we exported).

This command uses dot notation.

If you just run npm run pluck, you will be greeted with this object structure:

{
  rand: {
    random_array: [Function],
    pluck_random: [Function],
    shuffle: [Function],
    shuffle_for: [Function],
    random_hex: [Function]
  },
  array: { seq: [Function], xtract: [Function] }
}

If you want to export the xtract function, you would run:

npm run pluck array.xtract

Specifying the inverse

You can use npm run pluck-except <name>... to pluck everything except for a few functions.

npm run pluck-except rand.shuffle

This will extract the entire library except for shuffle

RNG API (for Arrays)

Grabbing a random array element

const {pluck_random} = require('@mentoc/utils').rand

const data = [1,2,3,4,5,6,7,8,9,10]

console.log(pluck_random(data))

Generate an array of fixed length with random numbers between a range

const {random_array} = require('@mentoc/utils').rand

/**
 * Generate a random array of 20 elements.
 * Each element is between the number 1 and 100
 */
let data_set = random_array(1,100,20)

console.log(data_set)

Shuffle an array

const {shuffle} = require('@mentoc/utils').rand

const data_set = [1,2,3,4,5,6,7,8,9,10]

console.log(shuffle(data_set))

Shuffle an array by passing in more/less rounds

Maybe you want the algorithm to shuffle more than just one time. For this, you can use the shuffle_for function. It accepts a number of rounds as it's second parameter.

const {shuffle_for} = require('@mentoc/utils').rand

const data_set = [1,2,3,4,5,6,7,8,9,10]

/**
 * This is equivalent to calling shuffle(data_set) 250 times in a loop
 */
console.log(shuffle_for(data_set,250))

Dot notation API

Use dot notation to grab an element out of a deeply nested structure

const {xtract} = require('@mentoc/utils').array
/** Grab an element out of a deeply nested structure */
let obj = [
    {
        user: {
            id: 1,
            name: "Larry Kenobi",
        }
    },
    {
        user: {
            id: 2,
            name: "Jerry Kenobi",
        }
    },
    {
        user: {
            id: 3,
            name: "John Kenobi",
        }
    }
]

let larry_schema = '0.user.name'
let john_schema = '2.user.name'
console.log('Example dataset: ',obj)

console.log(xtract(obj,larry_schema))    // prints "Larry Kenobi"
console.log(xtract(obj,john_schema))     // prints "John Kenobi"

Use dot notation to delete an element out of a deeply nested structure

const {prune} = require('@mentoc/utils').array
/** Delete an element out of a deeply nested structure */
let obj = [
    {
        user: {
            id: 1,
            name: "Larry Kenobi",
        }
    },
    {
        user: {
            id: 2,
            name: "Jerry Kenobi",
        }
    },
    {
        user: {
            id: 3,
            name: "John Kenobi",
        }
    }
]
console.log(prune(obj,'1.user.name'))   // removes name: "Jerry Kenobi" from object

Alternate notation API

There are times when you simply cannot pass in a dot notation in order to crawl a deeply nested structure. An object key can be any string value. This complicates matters and breaks the dot notation API. That is why the following functions accept either a string or an array as the second parameter.

xtract using an array schema

const {xtract} = require('@mentoc/utils').array
const first = "-1-_ yes, @#!_this is a valid key\"\"'"
const second = '_9-1 j#'
const weird_object = {
    "-1-_ yes, @#!_this is a valid key\"\"'": [
        {
            'z -1 +4': {
                id: 1,
                name: 'john doe'
            },
            '_9-1 j#': {
                id: 2,
                name: 'jane doe',
            },
        }
    ]
}
/**
 * Notice how we are passing in an array as opposed to a string for the 
 * second parameter here.
 */
let jane_doe = xtract(weird_object,[first,0,second,'name'])
console.log(jane_doe) // will print "jane doe"

prune using an array schema

const {prune} = require('@mentoc/utils').array
const first = "-1-_ yes, @#!_this is a valid key\"\"'"
const second = '_9-1 j#'
const weird_object = {
    "-1-_ yes, @#!_this is a valid key\"\"'": [
        {
            'z -1 +4': {
                id: 1,
                name: 'john doe'
            },
            '_9-1 j#': {
                id: 2,
                name: 'jane doe',
            },
        }
    ]
}
/**
 * Notice how we are passing in an array as opposed to a string for the 
 * second parameter here.
 */
let pruned = prune(weird_object,[first,0,second,'name'])
console.log('removed the name of the object with id 2: ',pruned[first][0])

// output of above console.log:
// removed the name of the object with id 2:  { 'z -1 +4': { id: 1, name: 'john doe' }, '_9-1 j#': { id: 2 } }

Array generation API

Generate an array of sequential numbers

const {seq} = require('@mentoc/utils').array

/**
 * The next line creates: [1,2,3,4,5,6,7]
 */
const data_set = seq(1,7)

RNG API (for Strings)

Grabbing a random string of hexadecimal characters

const {random_hex} = require('@mentoc/utils').rand

const length = 16

console.log(random_hex(16))	// Prints out 16 hex chars (without prepending zeroes)

Using the pluck npm commands

As stated above, you can export only the functions you need. This is all done for you through the pluck npm commands. Here are the available commands:

pluck

Description: Pass in several dot-notation functions that you would like to export to lib.js
Syntax: npm run pluck category.name... [category.name-N]
Example: npm run pluck rand.shuffle rand.rand_between

pluck-except

Description: Export every function EXCEPT for the functions you specify
Syntax: npm run pluck-except category.name... [category.name-N]
Example: npm run pluck-except rand.shuffle # exports the whole library except for rand.shuffle