Declarations broken under Vite when upgrading @vitejs/plugin-vue to v1.8

[mseele]

What happens and why it is wrong

After updateing @vitejs/plugin-vue version typescript generation via rollup-plugin-typescript2 is broken.
Using version 1.7.1 of @vitejs/plugin-vue the generation via rollup-plugin-typescript2 works like expected.

From version 1.8.0 it does not longer generate type definitions for components but list them in the index.d.ts file.

Reproduction

• Checkout https://github.com./mseele/vite-typescript2-output-broken, run yarn install and then yarn build
• In the dist directory a index.d.ts file will be generated with the reference to ./components/Hello.vue
• The ./components/Hello.vue.d.ts file will not be generated
• Change @vitejs/plugin-vue in package.json to 1.7.1, run yarn install and then yarn build again
• Everything works as expected: the missing ./components/Hello.vue.d.ts file has been generated

See also

Please see vitejs/vite#5044 i've opened in vite repo

[zeusdeux]

Would the ordering make a difference, i.e., moving rpt2 above vue? I'd think vue is stripping away types before source is fed to rpt2

[agilgur5]

Reading this issue and the one in Vite, as well as its linked issues, it sounds very much like a regression in Vite with the root cause already found there.

Will be closing this as out-of-scope then, but let us know if this needs reopening down the line if contraindicating info pops up.

[agilgur5]

Per the upstream issue, seems like this was fixed in vitejs/vite#7909 and released in @vitejs/plugin-vue v3.0.0-alpha.0