Allow export type for module = none

Search Terms

allow export type module none

Suggestion

For "module": "none", please allow export type Foo = { ... }

Use Cases

For ExtendScript code, tsc shouldn't generate export in generated js file.
For ts < 4.0, I can use "module": "ESNext"；for ts >= 4.0，I have to use "module": "none"(in ts 4.0.2，"module": "ESNext" will generate export {}, that is error for Extendscript)，but I cannot use export type ... in "module": "none", I use export type ... to reuse types between Extendscript and browser js code.
This blocks me to upgrade to typescript 4.0

Examples

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Start by reproducing the issue with tsc using "module": "none" and an export type declaration, then compare it with "module": "ESNext" and the behavior described for TypeScript 4.0. Review the compiler's module handling and declaration emit tests to determine the expected output. Done means export type is accepted with module none and no runtime export is emitted.