GeezerVison is showing github.com — export default type · Issue #41409 · microsoft/TypeScript
export default type #41409DescriptionSearch Terms
export default type
Suggestion
Allow export default for type.
Use Cases
It would be very nice to have export default type to match with other default exports such as classes and interfaces.
Right now it looks very inconsistent to be able to export anything as default and only types with named export:
export default class MyClass {}
export default interface MyInterface {}
export type MyType = {}The only way to achieve this now is to use annoying workaround:
type X = number | string
export { X as default }This may cause confusion for newbies as there are no clear reasons why classes and interfaces can be exported as default, but not the types.
Examples
// x.ts
export default type X = {}
// main.ts
import X from './x'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.
(not sure on the last) Reacted by somerandomdev49, Jayden Seric, Sam Reid, Michael Kauzmann, nai 🖤, whzx5byb, Dmitriy Zasukha, Tim Peko, Joshua Turner, Dannii Willis and 33 more Reacted by Gerrit Birkeland, Martin Johns, Pau Colomé and Mr. Binary Sniper Reacted by silverwind Activityharrysolovay commented on Dec 3, 2020 I often want to export values which double as types. For instance.
export const Tag = Symbol.for("@my-app/entry.Tag");
export type Tag = typeof Tag;It feels to me like this should be possible with default exports as well. Reacted by Hopeless Programmer, John Louderback, Jóhann Guðmundsson, Tim Peko, JongHan Leem, ptrxyz and Gouvernathor hopeless-programmer-online commented on Apr 16, 2021 Reacted by John Louderback, Michael Kauzmann, Jóhann Guðmundsson, Dmitriy Zasukha, Tim Peko, Thundercraft5, AlexeiA, Henderson Pinto, MetaCrawler, Victorien Elvinger and 9 more Reacted by Henrique Silvério, Marek Legris and Martin Rabaud PolariTOON commented on Mar 28, 2023 TypeScript 5.0 (in #52203) introduced a new option called --verbatimModuleSyntax that makes the following code produce the following error: An 'export default' must reference a value when 'verbatimModuleSyntax' is enabled, but 'X' only refers to a type., because the default export X is not clearly marked as a type:
type X = number | string;
export default X; And a workaround is to mark X as a type in the export declaration by using a named export:
type X = number | string;
export type {X as default}; // or export {type X as default};But that looks fairly indirect. Having export default type X; would also help making that more straightforward. Reacted by Andrei, whzx5byb, Andre-John Mas, Son Nguyen and Squidgical AndreiSoroka commented on Sep 9, 2023 was:
type SomePayload = {
data1: number;
data2: string;
};
export default SomePayload;import type SomePayload from './SomePayload.type' now:
export type SomePayload = {
data1: number;
data2: string;
};import type { SomePayload } from './SomePayload.type'seems like a bug, because I have 1 type in 1 file Reacted by Yongki Kim, Joseph Earl, Mitchell, Aamnah , taylorhaught, Wolf Yuan, RobertSklv and Rayhan Kinan Muhannad movahhedi commented on May 14, 2024 For those who were looking for "Type annotations for export default", follow #13626. Gouvernathor commented on Jul 19, 2025
And a workaround is to mark X as a type in the export declaration by using a named export:
type X = number | string;
export type {X as default}; // or export {type X as default};
But that looks fairly indirect. Having export default type X; would also help making that more straightforward.
In addition, while the following is possible :
export type Fraction = IFraction;
export const Fraction = Implementation; The following gives an error :
export type { IFraction as default };
export default Implementation;because it doesn't allow multiple default exports.
As pointed out earlier, it means that my clients will need to write import { Fraction } from "fractions"; rather than import Fraction from "fractions";, and that the default export is not treated the same as the other exports. Squidgical commented on Nov 29, 2025 Would very much like to see this. I'm using verbatimModuleSyntax, and while I can default export interfaces just fine, I can't do that for type aliases. It's causing me to use an unpleasant mix of // @ts-* comments and breaking my own conventions.
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