import { test, vi, expect } from 'vitest';

test('repro', () => {
  class Foo {
    f() {
      return 'original';
    }
  }

  // initially there's no own properties
  const foo = new Foo();
  expect(foo.f()).toMatchInlineSnapshot(`"original"`);
  expect(Object.getOwnPropertyDescriptors(foo)).toMatchInlineSnapshot(`{}`);

  // mocked function in own property
  const spy = vi.spyOn(foo, 'f').mockImplementation(() => 'mocked');
  expect(foo.f()).toMatchInlineSnapshot(`"mocked"`);
  expect(Object.getOwnPropertyDescriptors(foo)).toMatchInlineSnapshot(`
    {
      "f": {
        "configurable": true,
        "enumerable": false,
        "value": [MockFunction f] {
          "calls": [
            [],
          ],
          "results": [
            {
              "type": "return",
              "value": "mocked",
            },
          ],
        },
        "writable": true,
      },
    }
  `);

  // probably original prototype method is not moved to own property
  spy.mockRestore();
  expect(foo.f()).toMatchInlineSnapshot(`"original"`);
  expect(Object.getOwnPropertyDescriptors(foo)).toMatchInlineSnapshot(`
    {
      "f": {
        "configurable": true,
        "enumerable": false,
        "value": [Function],
        "writable": true,
      },
    }
  `);
});