🔑 Key Mirror Prefix

A utility for creating an object with values equal to its keys, prefixed with a specified string. Ideal for Redux action types, analytics events, error codes, and other constants that need unique identifiers across modules.

• Motivation
• Example
  • The Problem
  • The Solution
• Usage
  • Installation
  • Importing
  • Basic Usage
  • Usage Without Prefix

Motivation

When building large or complex applications, managing constants like action types, event names, or error codes becomes repetitive and error-prone. Without prefixing, you either risk naming collisions across different areas of your app, or you manually add prefixes everywhere - leading to verbose, inconsistent code.

Key Mirror Prefix solves this by automatically prefixing groups of constants, ensuring uniqueness while keeping your code clean and maintainable. Whether you're building Redux actions, analytics events, or any other grouped constants, you get organised, collision-free identifiers with minimal effort.

Example

The Problem

Single object - verbose and error-prone:

import keyMirror from 'key-mirror'

export const REDUX_ACTIONS = keyMirror({
  CITIES_SEARCH_REQUEST: null,
  CITIES_SEARCH_SUCCESS: null,
  CITIES_SEARCH_FAILURE: null,
  COUNTRIES_SEARCH_REQUEST: null,
  COUNTRIES_SEARCH_SUCCESS: null,
  COUNTRIES_SEARCH_FAILURE: null,
})

console.log(REDUX_ACTIONS.CITIES_SEARCH_REQUEST) // "CITIES_SEARCH_REQUEST"
console.log(REDUX_ACTIONS.COUNTRIES_SEARCH_REQUEST) // "COUNTRIES_SEARCH_REQUEST"

Multiple objects - collision risk:

import keyMirror from 'key-mirror'

export const CITIES = keyMirror({
  SEARCH_REQUEST: null,
  SEARCH_SUCCESS: null,
  SEARCH_FAILURE: null,
})

export const COUNTRIES = keyMirror({
  SEARCH_REQUEST: null,
  SEARCH_SUCCESS: null,
  SEARCH_FAILURE: null,
})

console.log(CITIES.SEARCH_REQUEST) // "SEARCH_REQUEST"
console.log(COUNTRIES.SEARCH_REQUEST) // "SEARCH_REQUEST"

The Solution

Using Key Mirror Prefix - clean and collision-free:

import { keyMirrorPrefix } from 'keymirrorprefix'

export const CITIES = keyMirrorPrefix('CITIES', {
  SEARCH_REQUEST: null,
  SEARCH_SUCCESS: null,
  SEARCH_FAILURE: null,
})

export const COUNTRIES = keyMirrorPrefix('COUNTRIES', {
  SEARCH_REQUEST: null,
  SEARCH_SUCCESS: null,
  SEARCH_FAILURE: null,
})

console.log(CITIES.SEARCH_REQUEST) // "CITIES_SEARCH_REQUEST"
console.log(COUNTRIES.SEARCH_REQUEST) // "COUNTRIES_SEARCH_REQUEST"

Usage

Installation

Install the package as a dependency:

# Using npm
npm install keymirrorprefix

# Using yarn
yarn add keymirrorprefix

Importing

You can import keyMirrorPrefix using either CommonJS or ES Modules:

// Using CommonJS
const { keyMirrorPrefix } = require('keymirrorprefix')

// Using ES Modules
import { keyMirrorPrefix } from 'keymirrorprefix'

Basic Usage

Once you've imported keyMirrorPrefix, you can use it to create an object with keys mirrored as values, prefixed with a specified string:

const NAVIGATION = keyMirrorPrefix('NAVIGATION', {
  CLICK: null,
  CLOSE: null,
  OPEN: null,
})

const PANEL = keyMirrorPrefix('PANEL', {
  CLOSE: null,
  OPEN: null,
})

console.log(NAVIGATION.OPEN) // "NAVIGATION_OPEN"
console.log(PANEL.OPEN) // "PANEL_OPEN"

Usage Without Prefix

If you do not need a prefix, you can either pass null as the first argument to keyMirrorPrefix, or you can import and use keyMirror:

import { keyMirror, keyMirrorPrefix } from 'keymirrorprefix'

const ANALYTICS = keyMirrorPrefix(null, {
  SEARCH: null,
  SIGN_OUT: null,
})

const EVENTS = keyMirror({
  BLUR: null,
  FOCUS: null,
})

console.log(ANALYTICS.SEARCH) // "SEARCH"
console.log(EVENTS.BLUR) // "BLUR"