missing-in-node

Javascript functions that are needed repeatedly but are missing in NodeJS.

How to install and use

Run npm install missing-in-node or yarn add missing-in-node.

You can then use the module in your project as the example below illustrates:

const M = require("missing-in-node");

console.log(M.btoa("Encode this string")); // outputs: RW5jb2RlIHRoaXMgc3RyaW5n

Functions provided in this package

String functions

• atob(input: string) : string decodes a Base64 string
• btoa(input: string) : string encodes into a Base64 string
• chr(num: int) : string an alias for String.fromCharCode
• ord(char: string) : int an alias for String.prototype.charCodeAt
• reverse(input: string) : string returns the reversed string without modifying the original one
• startsWith(text: string, start: string) : bool returns true only if the first arg starts with the second arg
• endsWith(text: string, end: string) : bool returns true only if the first arg ends with the second arg
• occurences(haystack: string, needle: string) : int returns number of occurences of a string in another string
• multiplyString(str: string, count: int) : string returns he original string repeated count times

Time functions

• performance.now() : float returns the milliseconds that passed since the process started
• sleep(milliseconds) asynchronous function that sleeps the number of milliseconds provided in its argument

Random functions

• randomInt(n1: int, n2: int) : int fast but cryptographically insecure function that returns an integer between 0 and (n1 - 1) if only n1 is provided, otherwise an integer between n1 and (n2 - 1)
• randomIntWeighted(n1: int, n2: int, weight: float) : int same as ramdomInt but with weight parameter (between 0 and 1) that makes the random distribution leans towards n1 or n2
• randomIntsInRange(n1 : int, n2: int, count: int) : array returns an array with count numbers of sorted random integers between n1 and (n2 - 1)
• randomFloat(n1: float, n2: float) : float returns a float between 0 and n1 if only n1 is provided, otherwise a float between n1 and n2
• randomBool() : bool returns true or false randomly
• randomAlphaNumeric() : string returns a random alphanumeric character (from A-Z or a-z or 0-9)
• randomAlpha() : string returns a random alpha character (from A-Z or a-z)
• randomAlphaUpper() : string returns a random uppercase alpha character (from A-Z)
• randomAlphaLower() : string returns a random lowercase alpha character (from a-z)
• randomDigit() : string returns a random decimal digit character (from 0-9)
• randomHexDigit() : string returns a random hexadecimal digit character (from 0-9 or A-F)
• randomFromList(list: array) : any returns a random element from list
• randomWithPercentage(obj: object): any returns a random key from an object with format {"option1": percentage1, "option2": percentage2, ...}
• randomFromObject(obj: object): object returns a random key-value pair from an object
• crypto.randomInt(n1: int, n2: int) : int cryptograhically secure random integer generator
• crypto.getRandomValues(array) : array fills an array with random values similarly to its browser counterpart

Numerical functions

• bin(num: int) : string an alias for .toString(2)
• oct(num: int) : string an alias for .toString(8)
• hex(num: int) : string an alias for .toString(16)
• hex(text: string) : string converts a text or a binary string to hexadecimal string
• hex(arr: array) : string converts an array of bytes to hexadecimal string
• dec(num: string, base: int) : int an alias for parseInt(num, base)
• round(number: float or string, decimalDigits: int) : float rounds a number to a particular number of decimal digits
• reverse(input: number) : number returns the reversed number without modifying the original one
• factorial(num: int) : int calculates the factorial of a positive integer
• fibonacci(num: int) : int calculates the n-th number in fibonacci series using non-recursive method
• isPrime(num: int) : bool determines whether an integer is prime or not

List functions

• listEquals(list1, list2) : bool determines if two arrays or two sets are equal (for primitive type elements only)
• objectEquals(object1, object2) : bool determines if two objects or are equal (for primitive type values only)
• reverse(input: array) : array returns a reversed array without modifying the original one
• shuffle(arr: array) : array returns a shuffled array (using Knuth method) without modifying the original one
• union(set1: set, set2: set) : set returns the union of two sets
• intersection(set1: set, set2: set) : set returns the intersection of two sets
• difference(set1: set, set2: set) : set returns the difference of two sets
• clone(obj: any) : any returns a shallow copy of an object or an array

function-related functions

• repeatFunction(func: function, count: int, argsArray: array) : array executes a function count times and returns the function return values in an array
• multiFunction(arg: any, funcArray: array, classObj: object) : any applies the functions in funcArray in order on the argument arg; elements in funcArray must be either funciton objects if classObj is not supplied, or strings that represent methods of classObj otherwise
• runSequential(funcArray: array) : array executes functions in funcArray sequentially; each element in the array is an object in the form { func: funcObj, args: [] }; the return values are returned in the same order in an array
• runConcurrent(funcArray: array) : array executes functions in funcArray concurrently; each element in the array is an object in the form { func: funcObj, args: [] }; the return values are returned in the same order in an array
• benchmark(func: function, count: int, argsArray: array) executes a function count times and prints the to stdout the total execution time