Helper methods

A package that provides helper methods for common and not-so-common use cases

Contributions are welcome!

Installation

npm install helper-methods-js

Methods

• deepcopy
• dedupe
• indexesOf
• isAsyncFunction
• trimDelimeters

---

deepcopy

This method creates a deep copy of the provided object to the given depth. Beyond that depth, the object is shallow copied

Parameter	Description	Default Value
obj	The object to be copied	N/A
max_depth (optional)	Maximum depth to which the function would copy the object. Beyond this depth shallow copies would be created. A value of 0 implies that the entire object should be deep copied.	0

Sample usage

import { deepcopy } from 'helper-methods-js'

deepcopy({ name: 'bob' }, 0);

---

dedupe

This method provides implementation to remove duplicates from an array.

Parameter	Description	Default Value
array	The array that needs duplicates removed	N/A
condition (optional)	A function that returns either true or false. This condition is executed for each array value and the values for which it returns true are removed. In case this condition is not provided, elements are removed on equality comparison.	N/A

Sample usage

import { dedupe } from 'helper-methods-js'

const cars = [
  { name: "audi", owner: "a" },
  { name: "bmw", owner: "x" },
  { name: "audi", owner: "b" },
  { name: "bmw", owner: "b" },
];

dedupe(cars, (e, i) => e.owner === i.owner)

---

indexesOf

This method provides implementation to return indexes of all elements that match a specific condition

Parameter	Description	Default Value
array	The array that needs duplicates removed	N/A
condition	It can either be a value or a functions. In case of a function, the function should return true or false. This condition is executed for each array value and the values for which it returns true are added to the list of indexes returned. In case this condition is not provided, elements are removed on equality comparison.	N/A

Sample usage

import { indexesOf } from 'helper-methods-js'

const objs = [
  { age: 21, nationality: "a" },
  { age: 24, nationality: "a" },
  { age: 21, nationality: "b" },
  { age: 32, nationality: "c" },
  { age: 42, nationality: "b" },
  { age: 52, nationality: "c" },
  { age: 21, nationality: "a" },
]

const indexes = indexesOf(objs, (i: any) => i.nationality === "b")

---

isAsyncFunction

This method returns whether a function is async or not.

Parameter	Description	Default Value
fn	The function for which it needs to be determined whether it is async or not.	N/A

Sample usage

import { isAsyncFunction } from 'helper-methods-js'

const testFn = async () => {};
isAsyncFunction(testFn) // returns true

const testFnSync = () => {};
isAsyncFunction(testFnSync) // returns false

---

trimDelimeters

This method takes a string and removes the provided delimeters from the start and end of the string.

Parameter	Description	Default Value
str	The string to be trimed	N/A
delimeters	A list of delimeters to be trimned from the start and/or end of the string provided.	N/A
options (optional)	An object with values trimStart and trimEnd that represent if the string should only be trimmed from start and/or end respectively.	{ trimStart: true, trimEnd: true }

Sample usage

import { trimDelimeters } from 'helper-methods-js'

trimDelimeters("&&*ABC*(&", ["&", "*"]) // outputs "ABC*("