IsolatedDeclarations: emitted declarations inconsistent between `transpileDeclaration` API and TypeScript Playground

Acknowledgement

• I acknowledge that issues using this template may be closed without further explanation at the maintainer's discretion.

Example

NOTE: Enabled isolatedDeclaration and noCheck

Playground Link

// input
import { Comment } from '@vue/runtime-core'
//       ^^^^^^^ https://github.com/vuejs/core/blob/a177092754642af2f98c33a4feffe8f198c3c950/packages/runtime-core/src/vnode.ts#L70
export const comment: Comment 

// .d.ts output
export declare const comment: Comment;

This example is correct because the tsc checker analyzer Comment is a const variable defined in @vue/runtime-core. So the Comment who referenced by comment is actually referenced lib.dom.d.ts's Comment. But the output of this example in transpileDeclaration APi will same as the following example.

Another example

NOTE: Enabled isolatedDeclaration and noCheck

Playground Link

// input
import { Comment } from 'does-not-exist'
export const comment: Comment 

// .d.ts output
import { Comment } from 'does-not-exist';
export declare const comment: Comment;

This example is also correct because the tsc checker can't analyze what Comment is, so the Comment was kept in the output as it has been referenced by comment.

But If I want to use lib.dom.d.ts's Comment rather than imported it will be incorrect.

Expect Behaviour

In IsolatedDeclarations, Ideally, we shouldn't analyze imports, but if we stop analyzing, this will generate incorrect output.

So I suggest tsc should throw an error about the above cases when IsolatedDeclarations is enabled. This is also beneficial for third-party IsolatedDeclarations implementations.

BTW this issue I found when I fix the output mismatch between oxc-isolated-declarations and tsc