ts-tram-saga

Write tram style code in TypeScript. Define clear steps to fulfill a conditional and asynchronous transaction. Inspired by https://github.com/eventuate-tram/eventuate-tram-sagas

Usage

import { Builder } from '../../src/builder'
import { exec } from '../../src/runner'

Define a Saga

Create Order Example. see https://github.com/guAnsunyata/ts-tram-saga/tree/master/example

You can run the example test by npm run test:watch

Example Spec:

• Create order with idle state.
• If the transaction failed, run a compensation to reject the order.
• Request to Reserve Credit through a Promise
  • If it return CustomerNotFound or CustomerCreditLimitExceeded result, run corresponded handler and fail this transaction
  • If it resolve without Promise rejection. Approve the order.

const transaction = new Builder()
  .step()
    .invoke(this.createOrder)
    .withCompensation(this.createOrderCompensation)
  .step()
    .invoke(this.reserveCredit)
    .onReply(CustomerNotFound, this.handleCustomerNotFound)
    .onReply(CustomerCreditLimitExceeded, this.handleCustomerCreditLimitExceeded)
  .step()
    .invoke(this.approveOrder)
  .get()

// execute the saga defined above
await exec({
  steps: transaction,
})