Export * of empty module leads to TS2306 (not a module).

[floitsch]

Bug Report

When using export * from './empty' where empty is an empty module I get an error that the file is not a module.

// index.ts
export * from './empty';

and two empty files empty.d.ts and empty.js next to it.

🔎 Search Terms

• "TS2306"
• export * with empty module
• "is not a module"

🕗 Version & Regression Information

Happens in 4.4.4, and on all workbench versions.

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about "'export *' with empty modules".

⏯ Playground Link

Workbench link with relevant code

💻 Code

// @filename: index.ts
export * from './empty'

// @filename: empty.d.ts
// Comment.

// @filename: empty.js
// Comment.

🙁 Actual behavior

Error:

error TS2306: File 'empty.d.ts' is not a module

I can import empty modules, so why can't I export * from empty files?

🙂 Expected behavior

The export * should just be ignored, since the empty module doesn't export anything.

[fatcerberus]

This happens because TS treats files without any imports or exports as script code, not module code. The error should go away if you put export {} in the empty file.

https://www.typescriptlang.org/docs/handbook/2/modules.html#how-javascript-modules-are-defined

[floitsch]

I can't easily do that, as the javascript/typescript files are generated by the protobuf compiler.
But I agree that the behavior seems to defined in the documentation.
Not really sure what to do. Maybe I should file a bug against the protobuf compiler...

[typescript-bot]

This issue has been marked 'Working as Intended' and has seen no recent activity. It has been automatically closed for house-keeping purposes.