npm package: @stdlib/fs-read-ndjson
Description: Read a file as newline-delimited JSON.
Author: The Stdlib Authors
Latest version: 0.1.1

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<details>
  <summary>
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</details>

# readNDJSON

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Read a file as [newline-delimited JSON][ndjson].

<section class="installation">

## Installation

```bash
npm install @stdlib/fs-read-ndjson
```

</section>

<section class="usage">

## Usage

```javascript
var readNDJSON = require( '@stdlib/fs-read-ndjson' );
```

<a name="read-ndjson"></a>

#### readNDJSON( file\[, options], clbk )

Asynchronously reads a file as [newline-delimited JSON][ndjson].

```javascript
var join = require( 'path' ).join;

readNDJSON( join( __dirname, 'examples', 'fixtures', 'file.ndjson' ), clbk );

function clbk( error, data ) {
    if ( error ) {
        throw error;
    }
    console.log( data );
}
```

The function accepts the following `options`:

-   **encoding**: file encoding.
-   **flag**: file status flag.
-   **reviver**: [JSON][json] transformation function.

The `options` parameter may also be a string specifying the file `encoding`.

```javascript
var join = require( 'path' ).join;

readNDJSON( join( __dirname, 'examples', 'fixtures', 'file.ndjson' ), 'utf8', clbk );

function clbk( error, data ) {
    if ( error ) {
        throw error;
    }
    console.log( data );
}
```

#### readNDJSON.sync( file\[, options] )

Synchronously reads a file as [newline-delimited JSON][ndjson].

```javascript
var join = require( 'path' ).join;
var instanceOf = require( '@stdlib/assert-instance-of' );

var out = readNDJSON.sync( join( __dirname, 'examples', 'fixtures', 'file.ndjson' ) );
if ( instanceOf( out, Error ) ) {
    throw out;
}
console.log( out );
```

The function accepts the same `options` as [`readNDJSON()`](#read-ndjson) above.

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   If the `encoding` option is set to `utf8` and the file has a UTF-8 [byte order mark][bom] (BOM), the byte order mark is **removed** before attempting to parse as [newline-delimited JSON][ndjson].

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var join = require( 'path' ).join;
var readNDJSON = require( '@stdlib/fs-read-ndjson' );

var file = join( __dirname, 'examples', 'fixtures', 'file.ndjson' );

// Synchronously read file contents...
var data = readNDJSON.sync( file, 'utf8' );
// returns [...]

data = readNDJSON.sync( 'beepboop', {
    'encoding': 'utf8'
});
// returns <Error>

// Asynchronously read file contents...
readNDJSON( file, clbk );
readNDJSON( 'beepboop', clbk );

function clbk( error, data ) {
    if ( error ) {
        if ( error.code === 'ENOENT' ) {
            console.error( 'JSON file does not exist.' );
        } else {
            throw error;
        }
    } else {
        console.log( 'Package description: %s', data[2].description );
    }
}
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/fs-read-ndjson.svg
[npm-url]: https://npmjs.org/package/@stdlib/fs-read-ndjson

[test-image]: https://github.com/stdlib-js/fs-read-ndjson/actions/workflows/test.yml/badge.svg?branch=v0.1.1
[test-url]: https://github.com/stdlib-js/fs-read-ndjson/actions/workflows/test.yml?query=branch:v0.1.1

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/fs-read-ndjson/main.svg
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[stdlib]: https://github.com/stdlib-js/stdlib

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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/fs-read-ndjson/tree/deno
[deno-readme]: https://github.com/stdlib-js/fs-read-ndjson/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/fs-read-ndjson/tree/umd
[umd-readme]: https://github.com/stdlib-js/fs-read-ndjson/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/fs-read-ndjson/tree/esm
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[branches-url]: https://github.com/stdlib-js/fs-read-ndjson/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/fs-read-ndjson/main/LICENSE

[json]: http://www.json.org/

[ndjson]: http://www.ndjson.org/

[bom]: https://en.wikipedia.org/wiki/Byte_order_mark

</section>

<!-- /.links -->