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    # jsesc [![Build status](https://travis-ci.org/mathiasbynens/jsesc.svg?branch=master)](https://travis-ci.org/mathiasbynens/jsesc) [![Code coverage status](https://coveralls.io/repos/mathiasbynens/jsesc/badge.svg)](https://coveralls.io/r/mathiasbynens/jsesc) [![Dependency status](https://gemnasium.com/mathiasbynens/jsesc.svg)](https://gemnasium.com/mathiasbynens/jsesc)

Given some data, _jsesc_ returns a stringified representation of that data. jsesc is similar to `JSON.stringify()` except:

1. it outputs JavaScript instead of JSON [by default](#json), enabling support for data structures like ES6 maps and sets;
2. it offers [many options](#api) to customize the output;
3. its output is ASCII-safe [by default](#minimal), thanks to its use of [escape sequences](https://mathiasbynens.be/notes/javascript-escapes) where needed.

For any input, jsesc generates the shortest possible valid printable-ASCII-only output. [Here’s an online demo.](https://mothereff.in/js-escapes)

jsesc’s output can be used instead of `JSON.stringify`’s to avoid [mojibake](https://en.wikipedia.org/wiki/Mojibake) and other encoding issues, or even to [avoid errors](https://twitter.com/annevk/status/380000829643571200) when passing JSON-formatted data (which may contain U+2028 LINE SEPARATOR, U+2029 PARAGRAPH SEPARATOR, or [lone surrogates](https://esdiscuss.org/topic/code-points-vs-unicode-scalar-values#content-14)) to a JavaScript parser or an UTF-8 encoder.

## Installation

Via [npm](https://www.npmjs.com/):

```bash
npm install jsesc
```

In [Node.js](https://nodejs.org/):

```js
const jsesc = require('jsesc');
```

## API

### `jsesc(value, options)`

This function takes a value and returns an escaped version of the value where any characters that are not printable ASCII symbols are escaped using the shortest possible (but valid) [escape sequences for use in JavaScript strings](https://mathiasbynens.be/notes/javascript-escapes). The first supported value type is strings:

```js
jsesc('Ich ♥ Bücher');
// → 'Ich \\u2665 B\\xFCcher'

jsesc('foo 𝌆 bar');
// → 'foo \\uD834\\uDF06 bar'
```

Instead of a string, the `value` can also be an array, an object, a map, a set, or a buffer. In such cases, `jsesc` returns a stringified version of the value where any characters that are not printable ASCII symbols are escaped in the same way.

```js
// Escaping an array
jsesc([
  'Ich ♥ Bücher', 'foo 𝌆 bar'
]);
// → '[\'Ich \\u2665 B\\xFCcher\',\'foo \\uD834\\uDF06 bar\']'

// Escaping an object
jsesc({
  'Ich ♥ Bücher': 'foo 𝌆 bar'
});
// → '{\'Ich \\u2665 B\\xFCcher\':\'foo \\uD834\\uDF06 bar\'}'
```

The optional `options` argument accepts an object with the following options:

#### `quotes`

The default value for the `quotes` option is `'single'`. This means that any occurrences of `'` in the input string are escaped as `\'`, so that the output can be used in a string literal wrapped in single quotes.

```js
jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.');
// → 'Lorem ipsum "dolor" sit \\\'amet\\\' etc.'

jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.', {
  'quotes': 'single'
});
// → '`Lorem` ipsum "dolor" sit \\\'amet\\\' etc.'
// → "`Lorem` ipsum \"dolor\" sit \\'amet\\' etc."
```

If you want to use the output as part of a string literal wrapped in double quotes, set the `quotes` option to `'double'`.

```js
jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.', {
  'quotes': 'double'
});
// → '`Lorem` ipsum \\"dolor\\" sit \'amet\' etc.'
// → "`Lorem` ipsum \\\"dolor\\\" sit 'amet' etc."
```

If you want to use the output as part of a template literal (i.e. wrapped in backticks), set the `quotes` option to `'backtick'`.

```js
jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.', {
  'quotes': 'backtick'
});
// → '\\`Lorem\\` ipsum "dolor" sit \'amet\' etc.'
// → "\\`Lorem\\` ipsum \"dolor\" sit 'amet' etc."
// → `\\\`Lorem\\\` ipsum "dolor" sit 'amet' etc.`
```

This setting also affects the output for arrays and objects:

```js
jsesc({ 'Ich ♥ Bücher': 'foo 𝌆 bar' }, {
  'quotes': 'double'
});
// → '{"Ich \\u2665 B\\xFCcher":"foo \\uD834\\uDF06 bar"}'

jsesc([ 'Ich ♥ Bücher', 'foo 𝌆 bar' ], {
  'quotes': 'double'
});
// → '["Ich \\u2665 B\\xFCcher","foo \\uD834\\uDF06 bar"]'
```

#### `numbers`

The default value for the `numbers` option is `'decimal'`. This means that any numeric values are represented using decimal integer literals. Other valid options are `binary`, `octal`, and `hexadecimal`, which result in binary integer literals, octal integer literals, and hexadecimal integer literals, respectively.

```js
jsesc(42, {
  'numbers': 'binary'
});
// → '0b101010'

jsesc(42, {
  'numbers': 'octal'
});
// → '0o52'

jsesc(42, {
  'numbers': 'decimal'
});
// → '42'

jsesc(42, {
  'numbers': 'hexadecimal'
});
// → '0x2A'
```

#### `wrap`

The `wrap` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, the output is a valid JavaScript string literal wrapped in quotes. The type of quotes can be specified through the `quotes` setting.

```js
jsesc('Lorem ipsum "dolor" sit \'amet\' etc.', {
  'quotes': 'single',
  'wrap': true
});
// → '\'Lorem ipsum "dolor" sit \\\'amet\\\' etc.\''
// → "\'Lorem ipsum \"dolor\" sit \\\'amet\\\' etc.\'"

jsesc('Lorem ipsum "dolor" sit \'amet\' etc.', {
  'quotes': 'double',
  'wrap': true
});
// → '"Lorem ipsum \\"dolor\\" sit \'amet\' etc."'
// → "\"Lorem ipsum \\\"dolor\\\" sit \'amet\' etc.\""
```

#### `es6`

The `es6` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, any astral Unicode symbols in the input are escaped using [ECMAScript 6 Unicode code point escape sequences](https://mathiasbynens.be/notes/javascript-escapes#unicode-code-point) instead of using separate escape sequences for each surrogate half. If backwards compatibility with ES5 environments is a concern, don’t enable this setting. If the `json` setting is enabled, the value for the `es6` setting is ignored (as if it was `false`).

```js
// By default, the `es6` option is disabled:
jsesc('foo 𝌆 bar 💩 baz');
// → 'foo \\uD834\\uDF06 bar \\uD83D\\uDCA9 baz'

// To explicitly disable it:
jsesc('foo 𝌆 bar 💩 baz', {
  'es6': false
});
// → 'foo \\uD834\\uDF06 bar \\uD83D\\uDCA9 baz'

// To enable it:
jsesc('foo 𝌆 bar 💩 baz', {
  'es6': true
});
// → 'foo \\u{1D306} bar \\u{1F4A9} baz'
```

#### `escapeEverything`

The `escapeEverything` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, all the symbols in the output are escaped — even printable ASCII symbols.

```js
jsesc('lolwat"foo\'bar', {
  'escapeEverything': true
});
// → '\\x6C\\x6F\\x6C\\x77\\x61\\x74\\"\\x66\\x6F\\x6F\\\'\\x62\\x61\\x72'
// → "\\x6C\\x6F\\x6C\\x77\\x61\\x74\\\"\\x66\\x6F\\x6F\\'\\x62\\x61\\x72"
```

This setting also affects the output for string literals within arrays and objects.

#### `minimal`

The `minimal` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, only a limited set of symbols in the output are escaped:

* U+0000 `\0`
* U+0008 `\b`
* U+0009 `\t`
* U+000A `\n`
* U+000C `\f`
* U+000D `\r`
* U+005C `\\`
* U+2028 `\u2028`
* U+2029 `\u2029`
* whatever symbol is being used for wrapping string literals (based on [the `quotes` option](#quotes))

Note: with this option enabled, jsesc output is no longer guaranteed to be ASCII-safe.

```js
jsesc('foo\u2029bar\nbaz©qux𝌆flops', {
  'minimal': false
});
// → 'foo\\u2029bar\\nbaz©qux𝌆flops'
```

#### `isScriptContext`

The `isScriptContext` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, occurrences of [`` or `