Type-only/Emit-less TS files aren't being checked

[aomader]

Current Behavior

After creating a simple react-with-storybook tsdx project (using create), add the following files:

src/interfaces/test.ts:

export interface Foo {
  bar: asd; // should not compile!
}

src/interfaces/index.ts:

export * from './test';

src/index.tsx:

// ...
export * from './interfaces';

Using this setup, running npm run start "successfully" builds the package, although it should error out due to the above error.

In contrast, when I run tsc --noEmit, the error is successfully recognized.

Expected behavior

When running npm run start, I expect it to catch the error.

Your environment

Software	Version(s)
TSDX	0.13.2
TypeScript	3.9.3
npm	6.14.4
Node	14.1.10
Operating System	Win10

Find the minimal example from above here:
lib2.zip

[agilgur5]

Sounds like this might be similar to #527 which never provided a repro. test.ts is a type-only/emit-less import and its type isn't used anywhere, so it might just be pruned out by rollup-plugin-typescript2 or rollup itself

[ezolenko]

Yeah, rollup prunes unused sources, so rtp2 plugin might never see something not imported by entry file.

[agilgur5]

I did some research on this in the past few weeks/months and found a reference to the original issue in rollup-plugin-typescript (rollup/rollup-plugin-typescript#28) from @wessberg/rollup-plugin-ts's docs. That was then moved to rollup/plugins#71 which was supposedly fixed in @rollup/plugin-typescript v3.0.0

We don't use @rollup/plugin-typescript, but that issue has references from other plugins, e.g. this one wessberg/rollup-plugin-ts#29 which has a comment that refers to rollup-plugin-typescript2's issue: ezolenko/rollup-plugin-typescript2#24 (which also referenced from the original issue). ezolenko/rollup-plugin-typescript2#7 is perhaps a duplicate of that

@ezolenko thanks for responding here. Per that issue, I thought this was fixed by ezolenko/rollup-plugin-typescript2@448913d with the current code here? Does that only handle entry files? Can we workaround that? It seems like @wessberg/rollup-plugin-ts has fixed the emit-less/type-only issue in somehow.
Not sure if ezolenko/rollup-plugin-typescript2#211 is related given mention of "entry file"

[agilgur5]

@ezolenko following up about the above

[agilgur5]

Noting here that this type-only issue was reproduced upstream in ezolenko/rollup-plugin-typescript2#298.
I became a maintainer of rpt2 a couple of months ago and fixed that in ezolenko/rollup-plugin-typescript2#345 , which was released in rpt2 0.33.0

Not sure if ezolenko/rollup-plugin-typescript2#211 is related given mention of "entry file"

This was actually the root cause and all of my references were related -- type-only issues were the longest lasting and most common issues in rpt2.
ezolenko/rollup-plugin-typescript2#345 allowed a specific workaround to function for many use-cases, but I later fixed the root cause issue in ezolenko/rollup-plugin-typescript2#406, which was released in rpt2 0.34.0.