Backwards compatibility (2.4.0 → 3.0.0)

Audit date: 2026-08-06. Reference: hashmap 3.0.0.

Import patterns

Pattern	2.4.0	3.0.0	Notes
const HashMap = require('hashmap')	✅	✅	CJS patch makes export the constructor
require('hashmap').HashMap	✅	✅	Same function as default export
import HashMap from 'hashmap'	⚠️	✅	ESM default; 2.4 was CJS-only publish
import { HashMap } from 'hashmap'	❌	✅	Named export added in 3.0
import * as NS from 'hashmap'; new NS.default()	—	✅	Bare namespace is not constructible
<script> / IIFE new HashMap()	✅	✅	dist/hashmap.iife.js
require('hashmap/index.js')	✅	❌	Use package root; exports field blocks deep paths

API

API	2.4.0	3.0.0	Notes
remove()	deprecated	✅ alias of delete()	Kept
count()	deprecated	✅ alias of size	Kept
type()	✅	✅ deprecated	Kept
hash()	✅	❌ removed	No known dependents
size	✅	✅	Preferred over count()
Object keys by identity	_hmuid_ expando	WeakMap side table	No property added to user objects
clone() / copy() entry isolation	shared Entry refs (bug)	deep-copied entries	Matches documented 2.4 intent

TypeScript / @types/hashmap

	@types/hashmap@2.3.4	hashmap@3.0.0 bundled
Module shape	export = HashMap	export default + export { HashMap }
Generics	HashMap<TKey, TValue>	HashMap with unknown keys/values (use inference at call sites)
hash()	present	removed
size	not in DT types	size: number
count()	primary in DT	deprecated

Migration: npm uninstall @types/hashmap. Types ship with the package since 3.0.0.

// Before (@types/hashmap)
import HashMap = require('hashmap')
const map = new HashMap<string, number>()

// After (bundled types)
import HashMap from 'hashmap'
const map = new HashMap<string, number>()  // still works; keys/values are typed at use sites

Smoke tests (built artifact)

Run after npm run build:

node -e "const H=require('./dist/hashmap.cjs'); console.assert(typeof H==='function'&&H===H.HashMap)"
node -e "const {HashMap}=require('./dist/hashmap.cjs'); console.assert(typeof HashMap==='function')"
node --input-type=module -e "import H,{HashMap as N} from './dist/hashmap.js'; console.assert(H===N)"

Encoded in src/hashmap.test.ts → package import interop.

Dependent audit commands

gh search code "require('hashmap')" --limit 50
gh search code "from 'hashmap'" --limit 50
npm view hashmap version
npm view @types/hashmap version