npm package: @stdlib/fs-read-wasm
Description: Read a file as WebAssembly.
Author: The Stdlib Authors
Latest version: 0.2.3

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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>
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</details>

# Read WebAssembly

[![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 [WebAssembly][webassembly].

<section class="installation">

## Installation

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

</section>

<section class="usage">

## Usage

```javascript
var readWASM = require( '@stdlib/fs-read-wasm' );
```

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

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

Asynchronously reads a file as [WebAssembly][webassembly].

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

var fpath = join( __dirname, 'examples', 'fixtures', 'file.wasm' );
readWASM( fpath, onRead );

function onRead( error, buf ) {
    if ( error ) {
        throw error;
    }
    console.log( buf );
}
```

The function accepts the following `options`:

-   **flag**: file status flag.

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

Synchronously reads a file as [WebAssembly][webassembly].

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

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

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

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   In contrast to [`readFile()`][@stdlib/fs/read-file], neither function accepts an `encoding` option. As [WebAssembly][webassembly] is a binary file format, if provided an `encoding` option, the function **overrides** the option, setting the option value to `null`.
-   Both functions return [WebAssembly][webassembly] file content as a [`Uint8Array`][@stdlib/array/uint8].

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint-disable no-undef -->

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

```javascript
var join = require( 'path' ).join;
var hasWebAssemblySupport = require( '@stdlib/assert-has-wasm-support' );
var readWASM = require( '@stdlib/fs-read-wasm' );

var fpath = join( __dirname, 'examples', 'fixtures', 'file.wasm' );
readWASM( fpath, onRead );

function onRead( error, wasm ) {
    var bool;
    if ( error ) {
        throw error;
    }
    bool = hasWebAssemblySupport();

    // If WebAssembly is supported, create a WebAssembly module instance...
    if ( bool ) {
        wasm = new WebAssembly.Module( wasm );
        wasm = new WebAssembly.Instance( wasm, {} );
        console.log( wasm.exports.stdlib_hypot( 5.0, 12.0 ) );
    } else {
        console.log( wasm );
    }
}
```

</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-read-file`][@stdlib/fs/read-file]</span><span class="delimiter">: </span><span class="description">read the entire contents of a file.</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; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

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

[test-image]: https://github.com/stdlib-js/fs-read-wasm/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/fs-read-wasm/actions/workflows/test.yml?query=branch:v0.2.3

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

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

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

[webassembly]: https://webassembly.org/

[@stdlib/fs/read-file]: https://www.npmjs.com/package/@stdlib/fs-read-file

[@stdlib/array/uint8]: https://www.npmjs.com/package/@stdlib/array-uint8

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

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</section>

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