import { describe, expect, it, vi } from "vitest";
import { TransitionTransaction } from "@/scene/TransitionTransaction";

describe("TransitionTransaction", () => {
  it("rolls back when prepare fails and never commits", async () => {
    const prepareError = new Error("prepare failed");
    const prepare = vi.fn(async () => {
      throw prepareError;
    });
    const commit = vi.fn(async () => {});
    const rollback = vi.fn(async () => {});

    const transaction = new TransitionTransaction({
      prepare,
      commit,
      rollback,
    });

    await expect(transaction.execute()).rejects.toThrowError("prepare failed");
    expect(prepare).toHaveBeenCalledTimes(1);
    expect(rollback).toHaveBeenCalledTimes(1);
    expect(commit).not.toHaveBeenCalled();
  });

  it("rolls back when commit fails", async () => {
    const commitError = new Error("commit failed");
    const prepare = vi.fn(async () => {});
    const commit = vi.fn(async () => {
      throw commitError;
    });
    const rollback = vi.fn(async () => {});

    const transaction = new TransitionTransaction({
      prepare,
      commit,
      rollback,
    });

    await expect(transaction.execute()).rejects.toThrowError("commit failed");
    expect(prepare).toHaveBeenCalledTimes(1);
    expect(commit).toHaveBeenCalledTimes(1);
    expect(rollback).toHaveBeenCalledTimes(1);
  });
});