"vue-tsc" fails with "error TS2769: No overload matches this call" in "strict" mode

[tinobino]

Describe the bug
vue-tsc fails with "error TS2769: No overload matches this call" in when "strict" mode is configured in "tsconfig.json".

If the defineEmits part in the component is removed vue-tsc doesn't complain. Seems that this issue is somehow related with Vue version 3.2.46.

To Reproduce
https://stackblitz.com/edit/vitest-dev-vitest-nwzj9x?file=components%2FSlotComponent.vue,test%2FSlotComponent.test.ts,package.json&initialPath=__vitest

Expected behavior
vue-tsc does not fail for the example given.

[cexbrayat]

Hi @tinobino and thanks for the repro

After looking at your repro, it does look like there is an issue, but I don't know if that should be fixed in Vue core, VTU or Volar.

The error goes away if:

• Vue v3.2.45 is used
• if defineEmits is removed
• More surprising, if <slot /> is removed from the template

Let me ping @johnsoncodehk as he may have some idea of what's going on

[johnsoncodehk]

It seems due to DefineComponent type updates. It should fix if update this line:

test-utils/src/mount.ts

Line 204 in f68ceee

export function mount<T extends DefineComponent<any, any, any, any>>(

- export declare function mount<T extends DefineComponent<any, any, any, any, any>>(component: T, options?: ComponentMountingOptions<T>): VueWrapper<InstanceType<T>>;
+ export declare function mount<T extends DefineComponent<any, any, any, any, any, any, any, any, any, any>>(component: T, options?: ComponentMountingOptions<T>): VueWrapper<InstanceType<T>>;

[cexbrayat]

@johnsoncodehk Thanks for taking a look! Sadly, it doesn't look like it's fixing the issue
See #1974

[tinobino]

Hi guys! Any updates on this? This issue prevents us from upgrade to latest vue version.

[cexbrayat]

@johnsoncodehk kindly offered (on another channel) to refactor the types when he has time, so this issue will get fixed, but we can't give you a timeline.

In the meantime, you can still upgrade to the latest vue version, by adding an explication cast mount(SlotComponent as any, {...}). We understand this is not ideal, but that should unblock you to update

[spacedawwwg]

I've added this to an test-utils.d.ts file for now and it seems to get us by without needing to modify all our test files and cast every component as any

// TODO: Remove once https://github.com/vuejs/test-utils/issues/1973 is resolved
declare module '@vue/test-utils' {
  // eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/ban-types
  export function mount<T extends DefineComponent<{}, {}, any>>(
    component: T,
    options?: ComponentMountingOptions<T>
  ): VueWrapper<InstanceType<T>>;
}

[johnsoncodehk]

I will check it out next week.

[dschmidt]

I've added this to an test-utils.d.ts file for now and it seems to get us by without needing to modify all our test files and cast every component as any

// TODO: Remove once https://github.com/vuejs/test-utils/issues/1973 is resolved
declare module '@vue/test-utils' {
  // eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/ban-types
  export function mount<T extends DefineComponent<{}, {}, any>>(
    component: T,
    options?: ComponentMountingOptions<T>
  ): VueWrapper<InstanceType<T>>;
}

Thanks, just a heads up: this should be put in a module file (i.e. with at least one top level export or import - in doubt add export {}) to make it a type augmentation, otherwise it replaces the module types completely and e.g. RouterLinkStub won't be available anymore.

[johnsoncodehk]

Please track #2026

[cexbrayat]

Thanks to @johnsoncodehk , the issue should be fixed in the next release (I added a test based on @tinobino repro to make sure we don't have this again).