time-to-botec/squiggle/node_modules/@stdlib/fs/read-json/README.md

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@license Apache-2.0
Copyright (c) 2018 The Stdlib Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
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distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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limitations under the License.
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# Read JSON
> Read a file as [JSON][json].
<section class="usage">
## Usage
```javascript
var readJSON = require( '@stdlib/fs/read-json' );
```
<a name="read-json"></a>
#### readJSON( file\[, options], clbk )
Asynchronously reads a file as [JSON][json].
```javascript
var join = require( 'path' ).join;
readJSON( join( __dirname, 'package.json' ), onJSON );
function onJSON( error, data ) {
if ( error ) {
throw error;
}
console.dir( 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;
readJSON( join( __dirname, 'package.json' ), 'utf8', onJSON );
function onJSON( error, data ) {
if ( error ) {
throw error;
}
console.dir( data );
}
```
#### readJSON.sync( file\[, options] )
Synchronously reads a file as [JSON][json].
```javascript
var join = require( 'path' ).join;
var instanceOf = require( '@stdlib/assert/instance-of' );
var out = readJSON.sync( join( __dirname, 'package.json' ) );
if ( instanceOf( out, Error ) ) {
throw out;
}
console.dir( out );
```
The function accepts the same `options` as [`readJSON()`](#read-json) 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 [JSON][json].
</section>
<!-- /.notes -->
<section class="examples">
## Examples
<!-- eslint no-undef: "error" -->
```javascript
var join = require( 'path' ).join;
var readJSON = require( '@stdlib/fs/read-json' );
var file = join( __dirname, 'package.json' );
// Synchronously read file contents...
var data = readJSON.sync( file, 'utf8' );
// returns <Object>
data = readJSON.sync( 'beepboop', {
'encoding': 'utf8'
});
// returns <Error>
// Asynchronously read file contents...
readJSON( file, onJSON );
readJSON( 'beepboop', onJSON );
function onJSON( 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.description );
}
}
```
</section>
<!-- /.examples -->
<section class="links">
[json]: http://www.json.org/
[bom]: https://en.wikipedia.org/wiki/Byte_order_mark
</section>
<!-- /.links -->