@dhmk/atom/esm/observable/array.js

Lightweight mobx-like observable values, computed values and side-effects

import { ValueAtom } from "../atoms/value";
var ID_ATOM = Symbol();
var makeMutable = function (name) {
    return function () {
        var args = [];
        for (var _i = 0; _i < arguments.length; _i++) {
            args[_i] = arguments[_i];
        }
        var self = this;
        self[name].apply(self, args);
        self[ID_ATOM].set({});
    };
};
var makePure = function (name) {
    return function () {
        var args = [];
        for (var _i = 0; _i < arguments.length; _i++) {
            args[_i] = arguments[_i];
        }
        var self = this;
        self[ID_ATOM].get();
        return self[name].apply(self, args);
    };
};
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array#copying_methods_and_mutating_methods
var mutableMethods = [
    "copyWithin",
    "fill",
    "pop",
    "push",
    "reverse",
    "shift",
    "sort",
    "splice",
    "unshift",
];
var patchedMethods = Object.create(null);
for (var _i = 0, _a = Object.getOwnPropertyNames(Array.prototype); _i < _a.length; _i++) {
    var k = _a[_i];
    var v = Array.prototype[k];
    if (typeof v === "function") {
        patchedMethods[k] = mutableMethods.includes(k)
            ? makeMutable(k)
            : makePure(k);
    }
}
export default function observableArray(x) {
    var idAtom = new ValueAtom({});
    x[ID_ATOM] = idAtom;
    return new Proxy(x, {
        get: function (t, p) {
            if (patchedMethods[p])
                return patchedMethods[p].bind(x);
            if (p === "length" || !isNaN(p))
                idAtom.get();
            return t[p];
        },
        set: function (t, p, v) {
            if (p === "length" || !isNaN(p)) {
                var prev = t[p];
                if (prev !== v)
                    idAtom.set({});
            }
            t[p] = v;
            return true;
        },
    });
}