@figliolia/size-observer/dist/types/types.d.ts

Resize Observers simplified

export type Callback<T extends any[], V = void> = (...args: T) => V;
export interface ElementProperties {
    width?: boolean;
    height?: boolean;
}
export type Dimensions = {
    [K in Extract<keyof ElementProperties, string>]: number;
};
export interface Options extends ElementProperties {
    onChange: Callback<[dimensions: Dimensions]>;
    type?: ResizeObserverBoxOptions;
}