uuid-fns

A glossary of intuitive, universally unambiguous uuid definitions and useful procedures.

Isomorphic - works in both Node.js and browser environments.

purpose

1. declare an intuitive and stable definition of Uuid

2. create a pit of success for uuid utilization

3. declare a ubiquitous language for

   • domain objects related to uuids
     • Uuid
   • domain operations related to uuids
     • isUuid
     • getUuid
     • getHash

install

npm install uuid-fns

use

Uuid

branded type for compile-time safety

import { Uuid, isUuid, getUuid } from 'uuid-fns';

// compile-time error: string is not assignable to Uuid
const id: Uuid = '550e8400-e29b-41d4-a716-446655440000'; // error

// use isUuid.assure to validate and cast
const id: Uuid = isUuid.assure('550e8400-e29b-41d4-a716-446655440000'); // ok

// or use getUuid which returns Uuid directly
const id: Uuid = getUuid(); // ok

isUuid

type guard to check if a string is a valid uuid

import { isUuid, Uuid } from 'uuid-fns';

// type guard usage
const maybeUuid = '550e8400-e29b-41d4-a716-446655440000';
if (isUuid(maybeUuid)) {
  // typescript now knows maybeUuid is of type Uuid
}

// check without assertion
isUuid('not-a-uuid'); // false
isUuid('550e8400-e29b-41d4-a716-446655440000'); // true

// runtime assertion - throws if invalid
const validUuid: Uuid = isUuid.assure('550e8400-e29b-41d4-a716-446655440000');

getUuid

get a new random uuid v4

import { getUuid, Uuid } from 'uuid-fns';

const id: Uuid = getUuid();
// e.g., '550e8400-e29b-41d4-a716-446655440000'

// each call returns a unique id
const id1 = getUuid();
const id2 = getUuid();
console.log(id1 === id2); // false

getHash

get a deterministic uuid from any string via SHA-1 hash (UUID v5)

import { getHash, isUuid } from 'uuid-fns';

// same input always returns the same uuid
const hash1 = getHash('hello');
const hash2 = getHash('hello');
console.log(hash1 === hash2); // true

// different inputs return different uuids
const hashA = getHash('hello');
const hashB = getHash('world');
console.log(hashA === hashB); // false

// use a custom namespace for isolation
const myNamespace = isUuid.assure('6ba7b810-9dad-11d1-80b4-00c04fd430c8');
const scopedHash = getHash('hello', { namespace: myNamespace });