[TEST] How to assert than an event was emitted ?

[a-kouyate]

I try to figure out how I add assertions in my test to assert that an event was emitted.

  emitEventStep({
      eventName: "custom.created",
      data: {
        id: "123",
        // other data payload
      },

[a-kouyate]

I found the response. For those who are interested to assert an event is emitted, you can process as follows:

import { medusaIntegrationTestRunner } from "@medusajs/test-utils";
import EventBusService from "@medusajs/test-utils/dist/mock-event-bus-service";
import { asValue } from "awilix";
import { Modules } from "@medusajs/framework/utils";

medusaIntegrationTestRunner({
  moduleName: "example-module",
  testSuite: ({ getContainer }) => {
    let fakeEventBus: jest.Mocked<EventBusService>;

    beforeAll(() => {
      const container = getContainer();

      // Mock EventBusService and spy on the `emit` method
      fakeEventBus = new EventBusService() as jest.Mocked<EventBusService>;
      jest.spyOn(fakeEventBus, "emit").mockImplementation(() => Promise.resolve());

      // Register the fake EventBus in the container
      container.register(Modules.EVENT_BUS, asValue(fakeEventBus));
    });

    it("should emits an event when workflow completes", async () => {
      const container = getContainer();

      // Example workflow input
      const exampleInput = { entityId: "example-id", value: "test-value" };

      const { result } = await exampleWorkflow(container).run({
        exampleInput,
      });

      // Validate workflow result
      expect(result.status).toEqual("success");

      // Assert that the event was emitted
      expect(fakeEventBus.emit).toHaveBeenCalledTimes(1);

      // Assert the event type and payload
      const [eventType] = fakeEventBus.emit.mock.calls[0];
      expect(eventType[0].name).toEqual("example.event.completed");
      expect(eventType[0].data).toEqual({ entityId: "example-id", status: "completed" });
    });
  },
});

jest.setTimeout(60 * 1000);