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<details>
  <summary>
    About stdlib...
  </summary>
  <p>We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.</p>
  <p>The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.</p>
  <p>When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.</p>
  <p>To join us in bringing numerical computing to the web, get started by checking us out on <a href="https://github.com/stdlib-js/stdlib">GitHub</a>, and please consider <a href="https://opencollective.com/stdlib">financially supporting stdlib</a>. We greatly appreciate your continued support!</p>
</details>

# Resolve Parent Path

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

> Resolve a path by walking parent directories.

<section class="installation">

## Installation

```bash
npm install @stdlib/fs-resolve-parent-path
```

</section>

<section class="usage">

## Usage

```javascript
var resolveParentPath = require( '@stdlib/fs-resolve-parent-path' );
```

<a name="resolve-parent-path"></a>

#### resolveParentPath( path\[, options], clbk )

Asynchronously resolves a path by walking parent directories.

```javascript
resolveParentPath( 'package.json', onPath );

function onPath( error, path ) {
    if ( error ) {
        throw error;
    }
    console.log( path );
    // => '...'
}
```

The function accepts the following `options`:

-   **dir**: base directory from which to begin walking. May be either an absolute path or a path relative to the current working directory.

By default, the function begins walking from the current working directory. To specify an alternative directory, set the `dir` option.

```javascript
var opts = {
    'dir': __dirname
};
resolveParentPath( 'package.json', opts, onPath );

function onPath( error, path ) {
    if ( error ) {
        throw error;
    }
    console.log( path );
    // => '...'
}
```

#### resolveParentPath.sync( path\[, options] )

Synchronously resolves a path by walking parent directories.

```javascript
var path = resolveParentPath.sync( 'package.json' );
// returns '...'
```

The function accepts the same `options` as [`resolveParentPath()`](#resolve-parent-path).

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   If unable to resolve a path, both functions return `null`.
-   This implementation is **not** similar in functionality to core [`path.resolve`][node-core-path-resolve]. The latter performs string manipulation to generate a full path. This implementation walks parent directories to perform a **search**, thereby touching the file system. Accordingly, this implementation resolves a _real_ absolute file path and is intended for use when a target's location in a parent directory is unknown relative to a child directory; e.g., when wanting to find a package root from deep within a package directory. 

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var resolveParentPath = require( '@stdlib/fs-resolve-parent-path' );

var opts = {
    'dir': __dirname
};

/* Sync */

var out = resolveParentPath.sync( 'package.json', opts );
// returns '...'

out = resolveParentPath.sync( 'non_existent_basename' );
// returns null

/* Async */

resolveParentPath( 'package.json', opts, onPath );
resolveParentPath( './../non_existent_path', onPath );

function onPath( error, path ) {
    if ( error ) {
        throw error;
    }
    console.log( path );
}
```

</section>

<!-- /.examples -->



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

<section class="related">

## See Also

-   <span class="package-name">[`@stdlib/fs-resolve-parent-path-cli`][@stdlib/fs-resolve-parent-path-cli]</span><span class="delimiter">: </span><span class="description">CLI package for use as a command-line utility.</span>
-   <span class="package-name">[`@stdlib/fs-resolve-parent-path-by`][@stdlib/fs/resolve-parent-path-by]</span><span class="delimiter">: </span><span class="description">resolve a path according to a predicate function by walking parent directories.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->


<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; 2016-2024. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[@stdlib/fs-resolve-parent-path-cli]: https://www.npmjs.com/package/@stdlib/fs-resolve-parent-path-cli

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

[test-image]: https://github.com/stdlib-js/fs-resolve-parent-path/actions/workflows/test.yml/badge.svg?branch=v0.2.2
[test-url]: https://github.com/stdlib-js/fs-resolve-parent-path/actions/workflows/test.yml?query=branch:v0.2.2

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/fs-resolve-parent-path/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/fs-resolve-parent-path?branch=main

<!--

[dependencies-image]: https://img.shields.io/david/stdlib-js/fs-resolve-parent-path.svg
[dependencies-url]: https://david-dm.org/stdlib-js/fs-resolve-parent-path/main

-->

[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg
[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im

[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[cli-section]: https://github.com/stdlib-js/fs-resolve-parent-path#cli
[cli-url]: https://github.com/stdlib-js/fs-resolve-parent-path/tree/cli
[@stdlib/fs-resolve-parent-path]: https://github.com/stdlib-js/fs-resolve-parent-path/tree/main

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

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/fs-resolve-parent-path/main/LICENSE

[node-core-path-resolve]: https://nodejs.org/api/path.html#path_path_resolve_paths

<!-- <related-links> -->

[@stdlib/fs/resolve-parent-path-by]: https://www.npmjs.com/package/@stdlib/fs-resolve-parent-path-by

<!-- </related-links> -->

</section>

<!-- /.links -->
