What is it?

This is a library for versioning given events. It's used to ensure that we are able to monitor the number of iterations of a given event and to ensure that we can re-build the original order.

How do I install it?

You can install it by using the following command:

npm install @jointly/event-versionator

Tests

You can run the tests by using the following command:

npm test

How does it work?

Just call the getVersionedEvent function with the event you want to version and it will return a new event with the versioning information.
the function expects to receive an object with the following properties:

• event - the event you want to version
• payload - the payload of the event

The return value is an object with the following properties:

• event - the given event
• version - the version of the event
• payload - the payload of the event
• createdAt - the date when the specific event version was created

const { getVersionedEvent } = require('@jointly/event-versionator');
getVersionedEvent({ event: 'ev1', payload: 'ev1-1' }); // { event: 'ev1', version: 1, payload: 'ev1-1', createdAt: '1970-01-01T14:00:00.000Z' }
getVersionedEvent({ event: 'ev1', payload: 'ev1-2' }); // { event: 'ev1', version: 2, payload: 'ev1-2', createdAt: '1970-01-01T14:00:03.123Z' }
getVersionedEvent({ event: 'ev1', payload: 'ev1-3' }); // { event: 'ev1', version: 3, payload: 'ev1-3', createdAt: '1970-01-01T14:00:06.246Z' }
getVersionedEvent({ event: 'ev2', payload: 'ev2-1' }); // { event: 'ev2', version: 1, payload: 'ev2-1', createdAt: '1970-01-01T14:00:09.369Z' }
getVersionedEvent({ event: 'ev2', payload: 'ev2-2' }); // { event: 'ev2', version: 2, payload: 'ev2-2', createdAt: '1970-01-01T14:00:12.492Z' }

Other Info

You can also call the getNextEventVersion function to get the next version of a given event.
By passing a false as the second argument, you can get the next version of the event without committing (saving it) in the function internal state.
You can also call the getNextEventVersion passing the EVENT_VERSIONING_RESET_STRING exported constant as the first argument to reset the internal state of the function and consequently resetting all saved version values.