Generic interface extending parameterized interface in TypeScript

Question

I have types like this where I overwrite single type while extending interface:

type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;

interface HTMLEvent<T> extends Omit<Event, 'target'> {
    target: T;
}

and now I want to create type EventType that will accept Event type for instance MouseEvent and target type.

I've tried this:

interface EventType<E, T> extends Omit<E, 'target'> {
    target: T;
}

const e: EventType<MouseEvent, HTMLButtonElement>;

but got error:

An interface can only extend an object type or intersection of object types with statically known members.

I think what I need is a function that will create a type.

Is interface EventType possible in TypeScript? Is it possible to have one generic type without the need to specify generic interface for each event type.

Titian Cernicova-Dragomir · Accepted Answer · 2019-01-14 18:21:16Z

3

The error is pretty clear about the restrictions placed on interface inheritance. Since the type contains an unresolved type parameter, Typescript will not let you use it in the extends clause of the interface.

You can get a similar effect using an intersection type instead :

type EventType<E extends Event, T> = Omit<E, 'target'> &  {
    target: T;
}

answered Jan 14, 2019 at 18:21

Titian Cernicova-Dragomir

253k37 gold badges464 silver badges394 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Generic interface extending parameterized interface in TypeScript

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related