find-array-duplicates

A utility function to find all duplicates within a provided object array

Information

Prerequisites

Node ^12.x nodejs.org

Install

npm i find-array-duplicates

or

yarn add find-array-duplicates

Usage

duplicates takes in 2 arguments arr and property. arr {Array} should be an Array containing a list of objects of a similar structure. property {String} is the property within the object structure that you would like to check for duplicate values.

import duplicates from 'find-array-duplicates'

duplicates(arr, 'property')

// => { single, all, modify, map, filter, find }

=> single()

Returns the first object of the filtered duplicates array

const names = [
  { 'age': 36, 'name': 'Bob' },
  { 'age': 40, 'name': 'Harry' },
  { 'age': 1,  'name': 'Bob' }
]

const results = duplicates(names, 'name').single()
// => { 'age': 36, 'name': 'Bob' }

=> all()

Returns the entire list of duplicate objects on the property provided

const results = duplicates(names, 'name').all()
// => [{ 'age': 36, 'name': 'Bob' }, { 'age': 1,  'name': 'Bob' }]

=> modify(callback)

Allows you to modify the output of the final result, the call back function is provided with the entire list of duplicate objects Returns any entirely in your control.

const results = duplicates(names, 'name').modify(dupes => dupes[0].age)
// => 36

=> find(callback)

Works exactly like Array.find runs off the duplicate array Returns an Object based on the find callback provided.

const results = duplicates(names, 'name').find(dupes => dupes.age === 1)
// => { 'age': 1,  'name': 'Bob' }

=> map(callback)

Works exactly like Array.map runs off the duplicate array Returns an Array based on the map callback provided.

const results = duplicates(names, 'name').map(({ name, age }, index) => { name, age, index })
// => [{ 'age': 1,  'name': 'Bob', index: 0 }, { 'age': 36, 'name': 'Bob', index: 1 }]

=> filter(callback)

Works exactly like Array.filter runs off the duplicate array. Returns an Array based on the filter callback provided.

const results = duplicates(names, 'name').filter(dupes => dupes.age >= 1)
// => [{ 'age': 1,  'name': 'Bob' }, { 'age': 36, 'name': 'Bob' }]

Please report issues on the github issue page. Hope you enjoy!