After discovering an error in the native Typescript interface for HTMLTextAreaElement, I realized the need to make a correction. The current interface looks like this:
interface HTMLTextAreaElement {
setSelectionRange(start: number, end: number): void;
}
However, upon closer inspection, I identified the correct version which should be:
interface HTMLTextAreaElement {
setSelectionRange(start?: number, end?: number, direction?: string): void;
}
I attempted to implement a quick fix by adding the correct interface to the same module where it's being used, but encountered issues as it just created a new interface with the same name. Another attempt was made by placing the code in a separate file named typings.d.ts, which holds common TypeScript declarations.
declare global {
interface HTMLTextAreaElement {
setSelectionRange(start?: number, end?: number, direction?: string): void;
}
}
Despite these efforts, the issue persisted. Further troubleshooting revealed that when trying to extend both my defined interface and the HTMLTextAreaElement interface using a third one, an error occurred:
interface Test {
setSelectionRange(start?: number, end?: number, direction?: string): void;
}
interface Extender extends Test, HTMLTextAreaElement {}
The error message displayed was:
Error: TS2320: Interface 'Extender' cannot simultaneously extend types 'Test' and 'HTMLTextAreaElement'. Named property 'setSelectionRange' of types 'Test' and 'HTMLTextAreaElement' are not identical.
My objective is to ensure that the Extender interface functions correctly, but I am unsure how to proceed. Is there a way to make this fix work effectively?
P.S. While I understand that ultimately this should be addressed by Typescript maintainers, I am seeking a temporary solution to resolve it promptly.