Allow type-only named re-exports along with assigned export in the same file

Search Terms

allow export types assigned =

Suggestion

The suggestion is to allow compilation of files that do both export = and export type {}.

Use Cases

For modules that target both TypeScript and CommonJS usage it would allow consolidating all exports for both module systems in one file (albeit with the requirement of esModuleInterop being true).

Currently, in order to do that I would have to utilize @ts-ignore (see parzh/xrange#69 for details).

Examples

/person.ts:

import personValue from "./person-value";

export = personValue;

export type { default as PersonType } from "./person-type";

/person-type.ts:

export default interface Person { name: string; }

/person-value.ts:

export default { name: "John Doe" } as import("./person-type").default;

Usage:

/usage.ts:

import personValue from "./person";
import personValue, { PersonType } from "./person";
import type { PersonType } from "./person";
import personValue = require("./person");

/usage.js:

const personValue = require("./person");

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.

The issue names the example files person.ts, person-type.ts, person-value.ts, and usage.ts, but no compiler files or tests. Start by locating how the compiler handles export = alongside type-only named exports, then verify the example compiles and that type-only exports do not alter emitted JavaScript.