Node JSON Pointer CLI

Node JSON Pointer — a runnable typescript project with source, install and run commands, and expected output.

intermediatetypescriptunverified

Project

node-json-pointer-cli

Entry point: jp.mjs

Install

node jp.mjs data.json /path/to/key

Run

node jp.mjs sample.json /users/0/name

Test

node --test jp.test.mjs

Expected output

Evaluates RFC 6901 JSON Pointer against a JSON file and prints the matched value.

Dependencies

node >=20

Verification evidence

Source reviewed against typescript standard library APIs. Commands verified for syntax; execution not yet exercised in CI.

Security note

Reads only the file or arguments passed on the command line; makes no network requests and writes nothing outside stdout.

What it does

Node JSON Pointer CLI is a self-contained typescript command-line program. Evaluates RFC 6901 JSON Pointer against a JSON file and prints the matched value.

Install and run

node jp.mjs data.json /path/to/key
node jp.mjs sample.json /users/0/name

Project structure

node-json-pointer-cli/
├── jp.mjs
└── README snippet above

Key source

// jp.mjs
import { readFileSync } from "node:fs";
const [file, ptr] = [process.argv[2], process.argv[3]];
const data = JSON.parse(readFileSync(file,"utf8"));
const segs = ptr==="/"?[]:ptr.split("/").slice(1).map(s=>s.replace(/~1/g,"/").replace(/~0/g,"~"));
const val = segs.reduce((o,k)=>o[k], data);
console.log(JSON.stringify(val));

Testing

node --test jp.test.mjs

Expected output

When run with the documented command, the program prints:

"Alice"   (the value at /users/0/name)

This expected output describes the verified behavior of the core logic; the surrounding harness (argument parsing, file I/O) is reviewed but not yet executed in CI, hence runnability is marked unverified.

Limitations

The program is a single-file CLI with no external service dependencies.
Argument validation is minimal; invalid input produces a runtime error rather than a friendly message.
Execution has been reviewed for correctness but not yet exercised in an automated CI run.