Api extractor will strip `declare var` content after bundling types

[ghiscoding]

Describe the bug

Hello, I seem to get a regression bug with the new v4.5.1 in my project, I'm getting this error but only with the new version. If I try again the old version, by fixing the version to 4.5.0 in my package.json, then it works again without errors.

[vite:dts] Internal Error: Unable to follow symbol for "__VLS_PrettifyGlobal"

Reproduction

https://github.com/ghiscoding/slickgrid-universal/actions/runs/13590117309/job/37997418809

Steps to reproduce

git clone https://github.com/ghiscoding/slickgrid-universal
pnpm install
pnpm run bundle
pnpm run vue:build:framework

Note after cloning the repo, you have to modify the frameworks/slickgrid-vue/package.json to use latest version of vite-plugin-dts which is not currently the latest since it caused a regression

The project is a monorepo, which might be a little too large but I hope that you can find the issue without requiring another project repro. Again it's really caused by the latest version only, 4.5.0 is ok but 4.5.1 is breaking

System Info

System:
    OS: Windows 11 10.0.22631
    CPU: (12) x64 Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
    Memory: 2.93 GB / 15.85 GB
  Binaries:
    Node: 20.13.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.22 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 10.9.0 - C:\Program Files\nodejs\npm.CMD
    pnpm: 9.15.5 - C:\GitHub\slickgrid-universal\node_modules\.bin\pnpm.CMD
  Browsers:
    Edge: Chromium (131.0.2903.112)
    Internet Explorer: 11.0.22621.3527
  npmPackages:
    @vitejs/plugin-vue: ^5.2.1 => 5.2.1 
    vite: catalog: => 6.0.11 
    vite-plugin-dts: ^4.5.1 => 4.5.1

Validations

• Read the FAQ.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.

[silverwind]

v3.5.1

You meant v4.5.1?

[ghiscoding]

v3.5.1

You meant v4.5.1?

oops... yes sorry, I inversed the number 😆 I updated the issue with the correct numbers. thanks

[skirtles-code]

I'm seeing the same problem with 4.5.1. I tried to create a minimal-ish reproduction:

https://github.com/skirtles-code/vite-plugin-dts-416-repro

It's based on the default project created using npm create vue@latest.

The main factors seem to be:

1. rollupTypes: true.
2. A component using <slot />.

[brc-dd]

locking volar to older version seems to work:

  "overrides": {
    "@vue/language-core": "2.2.0"
  }

Might be an upstream regression. Many things regarding slots were changed recently there.

[brc-dd]

bisecting shows this is the commit that broke - vuejs/language-tools@c4c0413

[qmhc]

@brc-dd Thanks for your research. I will degrade the version of @vue/language-core and release a new patch version.

[brc-dd]

It seems that the volar's global types block is missing in generated dist/App.vue.d.ts. If we can inject it there somehow it will work. Output without bundling should be similar to when you run pnpm vue-tsc --emitDeclarationOnly --declaration src/App.vue.

mkdist also is broken since newer releases. Also, this wasn't throwing without rollupTypes, but still the emitted types were broken.

https://github.com/vuejs/language-tools/blob/9b6911a95f13905f5f41a78cbb369bb8f1e65dde/packages/language-core/lib/codegen/globalTypes.ts#L20

[brc-dd]

vuejs/language-tools#5239 seems to fix the upstream issue and the intermediate files have correct types now. But the api extractor output is still wrong:

emitted code (by volar):

declare var __VLS_1: {};
type __VLS_Slots = {} & {
    default?: (props: typeof __VLS_1) => any;
};
declare const __VLS_component: import('vue').DefineComponent<{}, {}, {}, {}, {}, import('vue').ComponentOptionsMixin, import('vue').ComponentOptionsMixin, {}, string, import('vue').PublicProps, Readonly<{}> & Readonly<{}>, {}, {}, {}, {}, string, import('vue').ComponentProvideOptions, true, {}, any>;
declare const _default: __VLS_WithSlots<typeof __VLS_component, __VLS_Slots>;
export default _default;
type __VLS_WithSlots<T, S> = T & {
    new (): {
        $slots: S;
    };
};

bundled code:

import { ComponentOptionsMixin } from 'vue';
import { ComponentProvideOptions } from 'vue';
import { DefineComponent } from 'vue';
import { PublicProps } from 'vue';

declare const __VLS_component: DefineComponent<    {}, {}, {}, {}, {}, ComponentOptionsMixin, ComponentOptionsMixin, {}, string, PublicProps, Readonly<{}> & Readonly<{}>, {}, {}, {}, {}, string, ComponentProvideOptions, true, {}, any>;

declare type __VLS_Slots = {} & {
    default?: (props: typeof __VLS_1) => any;
};

declare type __VLS_WithSlots<T, S> = T & {
    new (): {
        $slots: S;
    };
};

export declare const App: __VLS_WithSlots<typeof __VLS_component, __VLS_Slots>;

export { }

Notice __VLS_1 declaration is stripped.

[qmhc]

@brc-dd Seems will be correct if __VLS_1 is defined by let: declare let __VLS_1: {};

[kleinfreund]

What's seemingly the underlying API extractor issue: microsoft/rushstack#5146

[qmhc]

With latest @vue/language-core the issue which occurred from the plugin is fixed.

To follow the original issue from Api extractor, please refer to microsoft/rushstack#5146.