Simulate and test a BPMN process

Testing a process by deploying it to Camunda, starting an instance, and watching Operate is slow feedback for something that should behave like a unit test. @bpmnkit/engine runs the same BPMN 2.0 XML you'd deploy to Camunda 8 entirely in-process, so a process test runs in milliseconds.

Writing a process test

import { Engine } from "@bpmnkit/engine";

const engine = new Engine();
engine.deploy({ bpmn: defs }); // defs is the built BpmnDefinitions, not exported XML

engine.registerJobWorker("payment-charge", async (job) => {
  job.complete({ chargeId: "test-123" });
});

const instance = engine.start("payment-flow", { orderId: "ord-1", amount: 42 });

// assert the instance reached the expected end event, took the expected
// gateway branch, and completed with the expected variables

Because job workers are just functions you register, a test can simulate a failing payment, a timeout, or any other edge case without touching a real external system — useful for exercising boundary-event error paths that are hard to trigger reliably against a live integration.

Where this fits in a pipeline

Generate a process with @bpmnkit/core, exercise it with @bpmnkit/engine, and only deploy to Camunda 8 with @bpmnkit/api once the simulation passes — the same shape as the Camunda 8 automation pipeline, with a fast correctness gate in the middle.

Frequently asked