diffable-objects/dist/observable.js

A package for dynamic state tracking for Cloudflare's Durable Objects using SQLite

import { atomizeChangeset, diff } from "json-diff-ts";
export function recursivelyObservable(data, opts) {
    const processUpdate = opts.processUpdate ??
        ((applyChanges) => {
            const old = structuredClone(data);
            applyChanges();
            const diffs = diff(old, data);
            const atomicChanges = atomizeChangeset(diffs);
            if (atomicChanges.length > 0) {
                opts.onUpdate(atomicChanges, data);
            }
        });
    const proxyOpts = {
        get(target, p) {
            const property = target[p];
            if (property !== null && typeof property === "object") {
                // @ts-ignore TODO
                return recursivelyObservable(property, {
                    ...opts,
                    processUpdate,
                });
            }
            return target[p];
        },
        set(target, p, newValue) {
            processUpdate(() => {
                target[p] = newValue;
            });
            return true;
        },
    };
    return new Proxy(data, proxyOpts);
}