This is a simple correlation id generator with the goal of simplifying the generation of correlation id

A correlation id should have the following format: <source system>-<pretty-unique-id> so that we can tell immediately:

• What it is e.g. a correlation id, not some UUID
• Where it originated

In my opinion, the following are good candidates to the <pretty-unique-id> part

• UUID: should be pretty unique
• A timestamp e.g. 1666797049350 from Date.now(): so that we knows when did the request happened, pretty good for low concurrency website
• A combination of session id with, says, a timestamp: so that we know from which session the request was triggered. A user Id can be a good session id, hence <user id>-<timestamp> is a valid example, e.g. johndoe-1666797049350
• A combination of session id with a timestamp and a random number: so that even with high concurrency, the chance of colision is low, e.g. johndoe-1666797049350-2514

Examples:

• ui-123e4567-e89b-12d3-a456-426614174000
• ui-1666797049350
• ui-1666797049350-5663
• storefront-johndoe-1666797049350
• shop-johndoe-1666797049350-2514

Sample Usages (adapted from unit tests):

const { correlationId } = require('simple-correlation-id');

it('generating timestamp by default', () => {
  const generated = correlationId(); 
});

it('prefix source system if supply', () => {
  const sourceSystem = 'test';
  const generated = correlationId(sourceSystem); 
});

it('pass the id generator as a function', () => {
  const generated = correlationId('test', () => 'id')
});

it('pass the id generator an option', () => {
  const options = {
    idGenerator: () => 'id'
  };
  const generated = correlationId('test', options);
});

it('advance options: default values', () => {
  const options = { };
  const generated = correlationId('test', options);
});

it('advance options: override randSize', () => {
  const options = { randSize: 5 };
  const generated = correlationId('test', options);
});

it('advance options: override sessionId', () => {
  const options = { sessionIdInjector: () => 'session' };
  const generated = correlationId('test', options);
});

Supporting Typescript