@mittwald/react-use-promise/dist/esm/observable-value/ObservableValue.js

Simple and declarative use of Promises in your React components. Observe their state and refresh them in various advanced ways.

export class ObservableValue {
    value;
    // using unknown since otherwise the ObservableValue seems to be invariant on type T
    observers = new Set();
    constructor(value) {
        this.value = value;
    }
    notifyObservers(newValue) {
        this.observers.forEach((o) => o(newValue));
    }
    get observerCount() {
        return this.observers.size;
    }
    observe(observer) {
        this.observers.add(observer);
        return () => this.observers.delete(observer);
    }
    updateValue(newValue) {
        if (this.value === newValue) {
            return;
        }
        this.value = newValue;
        this.notifyObservers(newValue);
    }
}