Describe the JSON you want. Get exactly that.

select-json-by-json keeps only the fields your spec names and returns them as a new object or array. The spec is plain JSON shaped like the result you want, and your source is never modified.

npm install select-json-by-json

Engine v6.0, package v1.6.1, MIT licensed. Runs in Node.js and modern browsers.

Try it: tick the fields you want

Each tick adds a field to the spec. The result follows.

Source

Spec

Result

Running a built-in preview of the same rules.

The spec has three rules

`true`	Keep this field from the source as-is.
`{ ... }`	Go inside the nested object or array and apply the sub-spec.
Absent	Leave the field out of the result.

Use it

Pass the source first and the spec second. You always get a fresh projection back.

import { selectJson } from "select-json-by-json";

const result = selectJson(sales, {
  DATE: true,
  VOUCHERNUMBER: true,
  "ALLINVENTORYENTRIES.LIST": {
    STOCKITEMNAME: true,
    RATE: true
  }
});
// sales is untouched; result holds only the fields above

Install three ways

npm package

npm install select-json-by-json

// latest engine
import { selectJson } from "select-json-by-json";
// or pin a version
import { selectJson } from "select-json-by-json/v6";

npx: copy the engine

# copies v6 to ./select-json-by-json/
npx select-json-by-json

# choose a folder or version
npx select-json-by-json ./lib/engine \
  --version-target=v6

Plain JavaScript files, zero dependencies.

CDN in the browser

<script type="module">
import { selectJson } from
"https://keshavsoft.github.io/select-json-by-json/docs/dist/min.js";
console.log(selectJson(data, { DATE: true }));
</script>

Also available as globalThis.ks.selectJson.

Build and test

`npm test`	Runs the Node.js native test suite.
`npm run build`	Bundles the highest `src/vN` with Vite into `docs/dist/vN/min.js` and `docs/dist/min.js`.