@exadel/esl/modules/esl-utils/decorators/prop.js

Exadel Smart Library (ESL) is the lightweight custom elements library that provide a set of super-flexible components

/** Builds getter from provider */
function getter(provider) {
    return function () {
        return provider.call(this, this);
    };
}
/** Builds own property setter */
function setter(name, readonly) {
    if (readonly)
        return () => void 0;
    return function (value) {
        Object.defineProperty(this, name, {
            value,
            writable: true,
            configurable: true
        });
    };
}
/**
 * `@prop` is auxiliary decorator to define a field on the prototype level.
 *` @prop` can be used to override decorated property from the parent level
 *
 * You can also use an @override decorator in combination with ECMA Script class property definition:
 * `@prop() public field: any = initial value;`
 *
 * The class property initial value is a part of object creation, so it goes to the object itself,
 * while the @override value is defined on the prototype level.
 *
 * If the value is a provider function, it will be resolved via instance each time property accessed.
 *
 * @param value - value or PropertyProvider to set up in prototype
 * @param prototypeConfig - prototype property configuration
 */
export function prop(value, prototypeConfig = {}) {
    return function (obj, name) {
        if (Object.hasOwnProperty.call(obj, name)) {
            throw new TypeError('Can\'t override own property');
        }
        if (typeof value === 'function') {
            Object.defineProperty(obj, name, {
                get: getter(value),
                set: setter(name, prototypeConfig.readonly),
                enumerable: prototypeConfig.enumerable,
                configurable: true
            });
        }
        else {
            Object.defineProperty(obj, name, {
                value,
                writable: !prototypeConfig.readonly,
                enumerable: prototypeConfig.enumerable,
                configurable: true
            });
        }
        return { /* To make babel transpiler work */};
    };
}