diffable-objects/dist/tracker.js

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

import { applyChangeset, unatomizeChangeset, } from "json-diff-ts";
export function replay(actions, initialValue) {
    if (actions.length === 0) {
        return initialValue;
    }
    let data = actions[0].type === "snapshot" ? actions[0].value : initialValue;
    assertChanges(actions);
    const atomicChanges = actions.map((it) => it.atomicChange);
    const changeSet = unatomizeChangeset(atomicChanges);
    data = applyChangeset(data, changeSet);
    return data;
}
function assertChanges(actions) {
    if (actions.length === 0) {
        throw new Error("No changes to assert");
    }
    if (actions[0].type === "snapshot") {
        actions.shift();
    }
    actions.forEach((it, i) => {
        if (it.type !== "change") {
            throw new Error(`Expected changes, but got snapshot at index ${i}`);
        }
    });
}