Memory leak when using VueTour in vue-test-utils [BUG]

[GeorgeBetts]

Describe the bug Running a Vue Test Utils unit test with the VueTour package included produces a memory leak. When logging heap usage or detecting memory leaks in Jest, the memory usage can be seen increasing with every test, which only occurs when the VueTour package is included.

Take for example this following very basic vue component: Memory.vue

<template>
  <div>memory test</div>
</template>

<script>
export default {
  name: "MemoryTest",
};
</script>

And create a unit test for it: Memory.test.js

import { mount } from "@vue/test-utils";
import MemoryTest from "../components/MemoryTest.vue";
import { createLocalVue } from "@vue/test-utils";
const localVue = createLocalVue();

describe("MemoryTest", () => {
  let wrapper = null;

  beforeEach(() => {
    wrapper = mount(MemoryTest, { localVue });
  });

  afterEach(() => {
    wrapper.destroy();
  });

  it("performs a test", () => {
    expect(wrapper.text()).toContain("memory test");
  });
});

If I run this test with the following options node ./node_modules/jest/bin/jest.js --runInBand --logHeapUsage --silent --detect-leaks

The test passes successfully:

However, if the unit test file is edited to include the VueTour library, and the same test is ran, the --detect-leaks option will fail due to the test now leaking memory: Updated Memory.test.js file with issue present:

import { mount } from "@vue/test-utils";
import MemoryTest from "../components/MemoryTest.vue";
import VueTour from "vue-tour";
import { createLocalVue } from "@vue/test-utils";
const localVue = createLocalVue();
localVue.use(VueTour);

describe("MemoryTest", () => {
  let wrapper = null;

  beforeEach(() => {
    wrapper = mount(MemoryTest, { localVue });
  });

  afterEach(() => {
    wrapper.destroy();
  });

  it("performs a test", () => {
    expect(wrapper.text()).toContain("memory test");
  });
});

To Reproduce Steps to reproduce the behavior:

1. Create a new Vue project with the Memory.vue and Memory.test.js files described above (Jest and Vue Test Utils must be included in the project)
2. Run the unit test using the following command node ./node_modules/jest/bin/jest.js --runInBand --logHeapUsage --silent --detect-leaks
3. See the error in the console about a detected memory leak

Expected behaviour The tests should run without increasing the heap size every test. Or when the '--detect-leaks' option is used the test should pass instead of failing due to a memory leak.

Screenshots If you don't use the --detect-leaks option, the tests will pass but you will clearly be able to see increased memory usage with each test that passes. In the following screenshot, I included the VueTour package in jest_setup.js so that it would be used in every test, to show off the memory leak:

Desktop (please complete the following information):

• OS: Windows
• Browser: n/a
• vue-tour Version: 2.0.0
• Jest Version: 26.6.3
• @vue/test-utils Version: 1.3.0

Additional context The 'weak-napi' NPM package must be installed to use the '--detect-leaks' option in Jest.