esm output leaves behind dead namespace import

[Swatinem]

I use import * as ts from "typescript"; inside my code.
When targeting esm output in rollup, all the imports are rewritten to specific identifiers, but one import * as ts is left behind, which is not used anywhere in the resulting bundle.
The commonjs output works correctly in this regard.

• Rollup Version: 1.13.1
• Operating System (or Browser): arch
• Node Version: 11.15

How Do We Reproduce?

I wasn’t really able to reduce the testcase. I can’t reproduce it with simple examples in the REPL.
A whole repo repro is here:
https://github.com/Swatinem/rollup-plugin-dts/tree/v1.0.0

Expected Behavior

There should be no unused import * as ts left in the code.

Actual Behavior

One import * as ts in left behind, but the resulting ts identifier is not referenced anywhere in the code. All the other namespace imports are resolved to specific imports.

See the output here:
https://unpkg.com/rollup-plugin-dts@1.0.0/dist/rollup-plugin-dts.mjs

[lukastaegert]

Managed to create a minimal repro. It seems to require a combination of destructuring and a call expression:
https://rollupjs.org/repl?version=1.14.1&shareable=JTdCJTIybW9kdWxlcyUyMiUzQSU1QiU3QiUyMm5hbWUlMjIlM0ElMjJtYWluLmpzJTIyJTJDJTIyY29kZSUyMiUzQSUyMmltcG9ydCUyMColMjBhcyUyMHN0dWZmJTIwZnJvbSUyMCdleHRlcm5hbCclNUNuJTVDbmNvbnN0JTIwJTdCeCU3RCUyMCUzRCUyMHN0dWZmLnkoKSUzQiUyMiUyQyUyMmlzRW50cnklMjIlM0F0cnVlJTdEJTVEJTJDJTIyb3B0aW9ucyUyMiUzQSU3QiUyMmZvcm1hdCUyMiUzQSUyMmVzbSUyMiUyQyUyMm5hbWUlMjIlM0ElMjJteUJ1bmRsZSUyMiUyQyUyMmFtZCUyMiUzQSU3QiUyMmlkJTIyJTNBJTIyJTIyJTdEJTJDJTIyZ2xvYmFscyUyMiUzQSU3QiU3RCU3RCUyQyUyMmV4YW1wbGUlMjIlM0FudWxsJTdE

If you change the assignment to not use the destructuring, the issue does not show:
https://rollupjs.org/repl?version=1.14.1&shareable=JTdCJTIybW9kdWxlcyUyMiUzQSU1QiU3QiUyMm5hbWUlMjIlM0ElMjJtYWluLmpzJTIyJTJDJTIyY29kZSUyMiUzQSUyMmltcG9ydCUyMColMjBhcyUyMHN0dWZmJTIwZnJvbSUyMCdleHRlcm5hbCclNUNuJTVDbmNvbnN0JTIweCUyMCUzRCUyMHN0dWZmLnkoKS54JTNCJTIyJTJDJTIyaXNFbnRyeSUyMiUzQXRydWUlN0QlNUQlMkMlMjJvcHRpb25zJTIyJTNBJTdCJTIyZm9ybWF0JTIyJTNBJTIyZXNtJTIyJTJDJTIybmFtZSUyMiUzQSUyMm15QnVuZGxlJTIyJTJDJTIyYW1kJTIyJTNBJTdCJTIyaWQlMjIlM0ElMjIlMjIlN0QlMkMlMjJnbG9iYWxzJTIyJTNBJTdCJTdEJTdEJTJDJTIyZXhhbXBsZSUyMiUzQW51bGwlN0Q=

[lukastaegert]

Thanks, there was really something we missed in our code, fix at #2900

[Swatinem]

Amazing how quickly you fix these things, thanks :-)