object-no-new-keys/README.md

Check, does a plain object (AST/JSON) has any unique keys, not present in a reference object (another AST/JSON)

<h1 align="center">object-no-new-keys</h1>

<p align="center">Check, does a plain object (AST/JSON) has any unique keys, not present in a reference object (another AST/JSON)</p>

<p align="center">
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## Install

This package is [pure ESM](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c). If you're not ready yet, install an older version of this program, 3.1.0 (`npm i object-no-new-keys@3.1.0`).

```bash
npm i object-no-new-keys
```

## Quick Take

```js
import { strict as assert } from "assert";

import { noNewKeys } from "object-no-new-keys";

assert.deepEqual(
  noNewKeys(
    {
      a: {
        b: "b",
        c: "c",
      },
      x: "y",
    },
    {
      a: {
        c: "z",
      },
    },
  ),
  ["a.b", "x"],
);
```

## Documentation

Please [visit codsen.com](https://codsen.com/os/object-no-new-keys/) for a full description of the API.

## Contributing

To report bugs or request features or assistance, [raise an issue](https://github.com/codsen/codsen/issues/new/choose) on GitHub.

## Licence

MIT License

Copyright © 2010-2025 Roy Revelt and other contributors

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