jsonrail

JSON tools for Node.js: pointers (RFC 6901), patches (RFC 6902), structural diffs, and deep merge.

Zero runtime dependencies. Node 18+.

Install

npm install jsonrail

Quick start

import { get, set, diff, applyPatch, merge, pointerFromPath } from "jsonrail";

const doc = { user: { name: "Ada", tags: ["math"] } };

get(doc, "/user/name");                 // "Ada"
get(doc, pointerFromPath("user.tags[0]")); // "math"

const next = set(doc, "/user/age", 36);

const patch = diff(doc, next);
// [{ op: "add", path: "/user/age", value: 36 }]

applyPatch(doc, patch);

merge({ a: { x: 1 } }, { a: { y: 2 }, b: 3 });
// { a: { x: 1, y: 2 }, b: 3 }

Patch operations

add, remove, replace, move, copy, test.

applyPatch({ items: ["a"] }, [
  { op: "add", path: "/items/-", value: "b" },
  { op: "test", path: "/items/1", value: "b" },
]);

get, set, and remove do not mutate the original document.

License

MIT