@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` decorator: defines a prototype-level property (value or computed via provider) with optional flags.
 * - Static value: defined on prototype (writable unless `readonly`)
 * - Provider function: installed as getter; each access invokes provider with `(this)`; optional setter creates own value
 * - Readonly: setter becomes no-op (provider case) or value made non-writable (static case)
 * - Enumerable flag passed through
 * - Throws if attempting to decorate an already own property on the prototype object
 *
 * @param value - static value or provider function producing the value per access
 * @param prototypeConfig - configuration object with optional `readonly` and `enumerable` flags
 */
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 */};
    };
}