`export { a as "hello world" }` is valid JavaScript but invalid TypeScript

[jcbhmr]

Bug Report

🔎 Search Terms

"es2020"
"export as string"
"import as string export as string"

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about "exports"

⏯ Playground Link

Playground link with relevant code

💻 Code

// This typescript code...
const a = 34;
export { a as "hello world" };

🙁 Actual behavior

// ...generates this invalid JavaScript code.
const a = 34;
export { a as } from "hello world";
;

The input was valid JavaScript so I would expect (intuitively) for it to be valid TypeScript. This is currently not the case.

🙂 Expected behavior

// I expected this JavaScript code to be generted:
const a = 34;
export { a as "hello world" };

Current behavior in browsers and Node.js works with this syntax!

// But running this in the DevTools or Node.js REPL works just fine.
await import("data:text/javascript," + encodeURIComponent(`
const a = 34;
export { a as "hello world" };
`))

JavaScript seems to allow strings as import/export names:

import { "hello world" as a } from "./hello.js"
export { a as "hello world" };

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import#syntax
https://developer.mozilla.org/en-US/docs/web/javascript/reference/statements/export#syntax

[Josh-Cena]

Duplicate of #40594

[jcbhmr]

Oops! I didn't search thoroughly enough. 🤦‍♂️