internal-error-event.test.ts

import { describe, it, expect, vi } from "vitest";
import { RuntimeEventBus } from "../../src/events/runtime-events.js";

describe("runtime.internal.error event", () => {
  it("emits runtime.internal.error when a listener throws", () => {
    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
    const bus = new RuntimeEventBus();
    const internalErrors: any[] = [];

    bus.on("runtime.started", () => {
      throw new Error("listener boom");
    });
    bus.on("runtime.internal.error", (event) => {
      internalErrors.push(event);
    });

    bus.emit({
      name: "runtime.started",
      payload: { runtimeId: "rt-1", occurredAt: new Date().toISOString() }
    });

    expect(internalErrors).toHaveLength(1);
    expect(internalErrors[0].name).toBe("runtime.internal.error");
    expect(internalErrors[0].payload.eventName).toBe("runtime.started");
    expect(internalErrors[0].payload.errorMessage).toBe("listener boom");
    expect(internalErrors[0].payload.occurredAt).toBeDefined();

    errorSpy.mockRestore();
  });

  it("does not emit runtime.internal.error for its own listener failures (no loop)", () => {
    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
    const bus = new RuntimeEventBus();
    let internalErrorCount = 0;

    bus.on("runtime.internal.error", () => {
      internalErrorCount++;
      throw new Error("internal handler also fails");
    });

    // Trigger an error on a different event to cause internal error emission
    bus.on("runtime.started", () => {
      throw new Error("original fail");
    });

    expect(() => {
      bus.emit({
        name: "runtime.started",
        payload: { runtimeId: "rt-2", occurredAt: new Date().toISOString() }
      });
    }).not.toThrow();

    // Internal error listener was called once, but its own failure did not recurse
    expect(internalErrorCount).toBe(1);

    errorSpy.mockRestore();
  });

  it("handles non-Error thrown values in errorMessage", () => {
    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
    const bus = new RuntimeEventBus();
    const internalErrors: any[] = [];

    bus.on("runtime.started", () => {
      throw "string-throw";
    });
    bus.on("runtime.internal.error", (event) => {
      internalErrors.push(event);
    });

    bus.emit({
      name: "runtime.started",
      payload: { runtimeId: "rt-3", occurredAt: new Date().toISOString() }
    });

    expect(internalErrors).toHaveLength(1);
    expect(internalErrors[0].payload.errorMessage).toBe("string-throw");

    errorSpy.mockRestore();
  });

  it("does not emit runtime.internal.error when no listeners throw", () => {
    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
    const bus = new RuntimeEventBus();
    const internalErrors: any[] = [];

    bus.on("runtime.started", () => {});
    bus.on("runtime.internal.error", (event) => {
      internalErrors.push(event);
    });

    bus.emit({
      name: "runtime.started",
      payload: { runtimeId: "rt-4", occurredAt: new Date().toISOString() }
    });

    expect(internalErrors).toHaveLength(0);

    errorSpy.mockRestore();
  });
});