Bug: regression on wrapper.vm type in 2.4.0-alpha.0

[cexbrayat]

Describe the bug

test('mount component', async () => {
  expect(Hello).toBeTruthy();

  const wrapper = mount(Hello, {
    props: {
      count: 4,
    },
  });

  // something does not exist on vm
  expect(wrapper.vm.something).toBe(undefined);
});

To Reproduce
https://stackblitz.com/edit/vitest-dev-vitest-se33u3?file=package.json

The type checking throws in v2.3.2 (as it should because wrapper.vm.something does not exist):

test/basic.test.ts:13:21 - error TS2339: Property 'something' does not exist on type '{ $: ComponentInternalInstance; $data: {}; $props: { readonly count: number; key?: string | number | symbol; ref?: VNodeRef; ref_for?: boolean; ref_key?: string; ... 7 more ...; style?: unknown; }; ... 10 more ...; $watch<T extends string | ((...args: any) => any)>(source: T, cb: T extends (...args: any) => infer R ...'.

13   expect(wrapper.vm.something).toBe(undefined);

Bump to v2.4.0-alpha.0, and run the command again: the error is now not caught.

npm install && npm run tsc

Expected behavior

The error should be caught in v2.4.0

Related information:

  System:
    OS: Linux 5.0 undefined
    CPU: (2) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  npmPackages:
    @vue/test-utils: 2.4.0-alpha.0 => 2.4.0-alpha.0 
    vitest: latest => 0.31.0 
    vue: latest => 3.3.2 

Additional context

[cexbrayat]

@johnsoncodehk What do you think about this?

[johnsoncodehk]

It seems to be because @vue/test-utils is missing the dependent vue-component-type-helpers module, moving vue-component-type-helpers from devDependencies to dependencies should fix it.

If you need to avoid adding dependencies, copying the code from vue-component-type-helpers is also an option.

[cexbrayat]

It looks like it fixes the issue 👍