@psyqueue/plugin-saga

Saga compensation for PsyQueue workflows. Automatic rollback when a workflow step fails.

Installation

npm install @psyqueue/plugin-saga

Usage

import { saga } from '@psyqueue/plugin-saga'
import { workflows, workflow } from '@psyqueue/plugin-workflows'

q.use(workflows())
q.use(saga())

const def = workflow('payment')
  .step('reserve', reserveHandler, {
    compensate: async (ctx) => { await releaseReservation(ctx) },
  })
  .step('charge', chargeHandler, {
    after: 'reserve',
    compensate: async (ctx) => { await refundCharge(ctx) },
  })
  .build()

Configuration

No configuration options. The plugin listens for workflow:failed events and runs compensations automatically.

Depends on: workflows

How It Works

When a workflow step is dead-lettered, the saga plugin runs compensation handlers on all previously-completed steps in reverse completion order.

Events

| Event | Data | When | |-------|------|------| | workflow:compensating | { workflowId, definitionName } | Compensation starting | | workflow:compensated | { workflowId, definitionName } | All compensations succeeded | | workflow:compensation-failed | { workflowId, definitionName } | A compensation handler threw |

Documentation

See Workflow Plugins for detailed usage.

License

MIT