object-fill-missing-keys
Add missing keys into plain objects, according to a reference object
## 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, 8.1.0 (`npm i object-fill-missing-keys@8.1.0`).
```bash
npm i object-fill-missing-keys
```
## Quick Take
```js
import { strict as assert } from "assert";
import { fillMissing } from "object-fill-missing-keys";
// deleting key 'c', with value 'd'
assert.deepEqual(
fillMissing(
{
// input object that could have came from JSON
b: "b",
},
{
// schema reference object
a: false,
b: false,
c: false,
},
),
{
// patched result
a: false,
b: "b",
c: false,
},
);
```
## Documentation
Please [visit codsen.com](https://codsen.com/os/object-fill-missing-keys/) for a full description of the API. If you’re looking for the **Changelog**, it’s [here](https://github.com/codsen/codsen/blob/main/packages/object-fill-missing-keys/CHANGELOG.md).
## 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
