Vue-tsc Compilation Error for Simple TS File

[zhaoyuqiqi]

Vue - Official extension or vue-tsc version

2.2.0

VSCode version

1.96.0

Vue version

3.5.12

TypeScript version

5.6.2

System Info

No response

package.json dependencies

No response

Steps to reproduce

Declare a function and generate its type using vue-tsc

import { ref } from 'vue'

export function useResetRef<T>(initData: T) {
  const data = ref(initData)
  return data
}

Execute the command vue-tsc-declaration-emitdeclarationonly at the console

npx vue-tsc --declaration --emitDeclarationOnly

What is expected?

Not throw an error and output a type file

What is actually happening?

src/hooks/useResetRef.ts:4:17 - error TS2742: The inferred type of 'useResetRef' cannot be named without a reference to '.pnpm/@VUE[email protected]/node_modules/@vue/shared'. This is likely not portable. A type annotation is necessary.

4 export function useResetRef(initData: T) {
~~~~~~~~~~~

Link to minimal reproduction

https://codesandbox.io/p/devbox/9kmzhk?file=%2Fsrc%2Fhooks%2Fuse-reset.ts%3A5%2C15

Any additional comments?

No response

[RayGuo-ergou]

see #5089 (comment)

I don't have access to edit the codesandbox but in your case this probably will fix

import { ref, type Ref } from 'vue'

export function useResetRef<T>(initData: T) {
  const data: Ref<T> = ref(initData)
  return data
}

[tsukuha]

I could reproduce too error.

Reproduction

package.json

{
  ...(other properties)
  "dependencies": {
    "vue": "^3.5.13",
    "vue-tsc": "^2.2.0"
  }
}

test.vue

<script lang="ts">
import { ref } from 'vue'

export function useResetRef<T>(initData: T) {
  const data = ref(initData)
  return data
}

cmd

npx vue-tsc --declaration --emitDeclarationOnly ./test.vue

[RayGuo-ergou]

As mentioned above this is expected and it's how tsc works. ( you can call it limitation of typescript )

[RayGuo-ergou]

In this case specifically:

// 1.
export type IfAny<T, Y, N> = 0 extends 1 & T ? Y : N;
export function useResetRef<T>(initData: T) {
  const data: [T] extends [Ref] ? IfAny<T, Ref<T>, T> : Ref<UnwrapRef<T>, UnwrapRef<T> | T> = ref(initData)
  return data
}

// 2. 
export function useResetRef<T>(initData: T) {
  const data: Ref<T | undefined> = ref()
  data.value = initData
  return data
}

// 3.
export function useResetRef<T>(initData: T) {
  const data = ref(initData) as Ref<T>
  return data
}

// 4. Only work prior to vue 3.5 as the reactive system has refactored in 3.5
export function useResetRef<T>(initData: T) {
  const data: Ref<UnwrapRef<T>> = ref(initData) 
  return data
}

[tsukuha]

sorry, I missed read