Unit-Testing von Vue-Composables mit isoliertem App-Kontext

import { describe, it, expect } from 'vitest';
import { ref, createApp } from 'vue';
 
export function useCounter(initialValue = 0) {
  const count = ref(initialValue);
  const increment = () => { count.value++; };
  return { count, increment };
}
 
export function withSetup(composable) {
  let result;
  const app = createApp({
    setup() {
      result = composable();
      return () => {};
    }
  });
  app.mount(document.createElement('div'));
  return [result, app];
}
 
describe('useCounter', () => {
  it('increments count correctly within Vue scope', () => {
    const [counterApp, app] = withSetup(() => useCounter(5));
    expect(counterApp.count.value).toBe(5);
    counterApp.increment();
    expect(counterApp.count.value).toBe(6);
    app.unmount();
  });
});