sourav-das/stem-separator
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1# jsesc2 3Given some data, _jsesc_ returns a stringified representation of that data. jsesc is similar to `JSON.stringify()` except:4 51. it outputs JavaScript instead of JSON [by default](#json), enabling support for data structures like ES6 maps and sets;62. it offers [many options](#api) to customize the output;73. its output is ASCII-safe [by default](#minimal), thanks to its use of [escape sequences](https://mathiasbynens.be/notes/javascript-escapes) where needed.8 9For any input, jsesc generates the shortest possible valid printable-ASCII-only output. [Here’s an online demo.](https://mothereff.in/js-escapes)10 11jsesc’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.12 13## Installation14 15Via [npm](https://www.npmjs.com/):16 17```bash18npm install jsesc19```20 21In [Node.js](https://nodejs.org/):22 23```js24const jsesc = require('jsesc');25```26 27## API28 29### `jsesc(value, options)`30 31This 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:32 33```js34jsesc('Ich ♥ Bücher');35// → 'Ich \\u2665 B\\xFCcher'36 37jsesc('foo 𝌆 bar');38// → 'foo \\uD834\\uDF06 bar'39```40 41Instead 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.42 43```js44// Escaping an array45jsesc([46 'Ich ♥ Bücher', 'foo 𝌆 bar'47]);48// → '[\'Ich \\u2665 B\\xFCcher\',\'foo \\uD834\\uDF06 bar\']'49 50// Escaping an object51jsesc({52 'Ich ♥ Bücher': 'foo 𝌆 bar'53});54// → '{\'Ich \\u2665 B\\xFCcher\':\'foo \\uD834\\uDF06 bar\'}'55```56 57The optional `options` argument accepts an object with the following options:58 59#### `quotes`60 61The 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.62 63```js64jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.');65// → 'Lorem ipsum "dolor" sit \\\'amet\\\' etc.'66 67jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.', {68 'quotes': 'single'69});70// → '`Lorem` ipsum "dolor" sit \\\'amet\\\' etc.'71// → "`Lorem` ipsum \"dolor\" sit \\'amet\\' etc."72```73 74If you want to use the output as part of a string literal wrapped in double quotes, set the `quotes` option to `'double'`.75 76```js77jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.', {78 'quotes': 'double'79});80// → '`Lorem` ipsum \\"dolor\\" sit \'amet\' etc.'81// → "`Lorem` ipsum \\\"dolor\\\" sit 'amet' etc."82```83 84If you want to use the output as part of a template literal (i.e. wrapped in backticks), set the `quotes` option to `'backtick'`.85 86```js87jsesc('`Lorem` ipsum "dolor" sit \'amet\' etc.', {88 'quotes': 'backtick'89});90// → '\\`Lorem\\` ipsum "dolor" sit \'amet\' etc.'91// → "\\`Lorem\\` ipsum \"dolor\" sit 'amet' etc."92// → `\\\`Lorem\\\` ipsum "dolor" sit 'amet' etc.`93```94 95This setting also affects the output for arrays and objects:96 97```js98jsesc({ 'Ich ♥ Bücher': 'foo 𝌆 bar' }, {99 'quotes': 'double'100});101// → '{"Ich \\u2665 B\\xFCcher":"foo \\uD834\\uDF06 bar"}'102 103jsesc([ 'Ich ♥ Bücher', 'foo 𝌆 bar' ], {104 'quotes': 'double'105});106// → '["Ich \\u2665 B\\xFCcher","foo \\uD834\\uDF06 bar"]'107```108 109#### `numbers`110 111The 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.112 113```js114jsesc(42, {115 'numbers': 'binary'116});117// → '0b101010'118 119jsesc(42, {120 'numbers': 'octal'121});122// → '0o52'123 124jsesc(42, {125 'numbers': 'decimal'126});127// → '42'128 129jsesc(42, {130 'numbers': 'hexadecimal'131});132// → '0x2A'133```134 135#### `wrap`136 137The `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.138 139```js140jsesc('Lorem ipsum "dolor" sit \'amet\' etc.', {141 'quotes': 'single',142 'wrap': true143});144// → '\'Lorem ipsum "dolor" sit \\\'amet\\\' etc.\''145// → "\'Lorem ipsum \"dolor\" sit \\\'amet\\\' etc.\'"146 147jsesc('Lorem ipsum "dolor" sit \'amet\' etc.', {148 'quotes': 'double',149 'wrap': true150});151// → '"Lorem ipsum \\"dolor\\" sit \'amet\' etc."'152// → "\"Lorem ipsum \\\"dolor\\\" sit \'amet\' etc.\""153```154 155#### `es6`156 157The `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`).158 159```js160// By default, the `es6` option is disabled:161jsesc('foo 𝌆 bar 💩 baz');162// → 'foo \\uD834\\uDF06 bar \\uD83D\\uDCA9 baz'163 164// To explicitly disable it:165jsesc('foo 𝌆 bar 💩 baz', {166 'es6': false167});168// → 'foo \\uD834\\uDF06 bar \\uD83D\\uDCA9 baz'169 170// To enable it:171jsesc('foo 𝌆 bar 💩 baz', {172 'es6': true173});174// → 'foo \\u{1D306} bar \\u{1F4A9} baz'175```176 177#### `escapeEverything`178 179The `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.180 181```js182jsesc('lolwat"foo\'bar', {183 'escapeEverything': true184});185// → '\\x6C\\x6F\\x6C\\x77\\x61\\x74\\"\\x66\\x6F\\x6F\\\'\\x62\\x61\\x72'186// → "\\x6C\\x6F\\x6C\\x77\\x61\\x74\\\"\\x66\\x6F\\x6F\\'\\x62\\x61\\x72"187```188 189This setting also affects the output for string literals within arrays and objects.190 191#### `minimal`192 193The `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:194 195* U+0000 `\0`196* U+0008 `\b`197* U+0009 `\t`198* U+000A `\n`199* U+000C `\f`200* U+000D `\r`201* U+005C `\\`202* U+2028 `\u2028`203* U+2029 `\u2029`204* whatever symbol is being used for wrapping string literals (based on [the `quotes` option](#quotes))205* [lone surrogates](https://esdiscuss.org/topic/code-points-vs-unicode-scalar-values#content-14)206 207Note: with this option enabled, jsesc output is no longer guaranteed to be ASCII-safe.208 209```js210jsesc('foo\u2029bar\nbaz©qux𝌆flops', {211 'minimal': false212});213// → 'foo\\u2029bar\\nbaz©qux𝌆flops'214```215 216#### `isScriptContext`217 218The `isScriptContext` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, occurrences of [`</script` and `</style`](https://mathiasbynens.be/notes/etago) in the output are escaped as `<\/script` and `<\/style`, and [`<!--`](https://mathiasbynens.be/notes/etago#comment-8) is escaped as `\x3C!--` (or `\u003C!--` when the `json` option is enabled). This setting is useful when jsesc’s output ends up as part of a `<script>` or `<style>` element in an HTML document.219 220```js221jsesc('foo</script>bar', {222 'isScriptContext': true223});224// → 'foo<\\/script>bar'225```226 227#### `compact`228 229The `compact` option takes a boolean value (`true` or `false`), and defaults to `true` (enabled). When enabled, the output for arrays and objects is as compact as possible; it’s not formatted nicely.230 231```js232jsesc({ 'Ich ♥ Bücher': 'foo 𝌆 bar' }, {233 'compact': true // this is the default234});235// → '{\'Ich \u2665 B\xFCcher\':\'foo \uD834\uDF06 bar\'}'236 237jsesc({ 'Ich ♥ Bücher': 'foo 𝌆 bar' }, {238 'compact': false239});240// → '{\n\t\'Ich \u2665 B\xFCcher\': \'foo \uD834\uDF06 bar\'\n}'241 242jsesc([ 'Ich ♥ Bücher', 'foo 𝌆 bar' ], {243 'compact': false244});245// → '[\n\t\'Ich \u2665 B\xFCcher\',\n\t\'foo \uD834\uDF06 bar\'\n]'246```247 248This setting has no effect on the output for strings.249 250#### `indent`251 252The `indent` option takes a string value, and defaults to `'\t'`. When the `compact` setting is disabled (`false`), the value of the `indent` option is used to format the output for arrays and objects.253 254```js255jsesc({ 'Ich ♥ Bücher': 'foo 𝌆 bar' }, {256 'compact': false,257 'indent': '\t' // this is the default258});259// → '{\n\t\'Ich \u2665 B\xFCcher\': \'foo \uD834\uDF06 bar\'\n}'260 261jsesc({ 'Ich ♥ Bücher': 'foo 𝌆 bar' }, {262 'compact': false,263 'indent': ' '264});265// → '{\n \'Ich \u2665 B\xFCcher\': \'foo \uD834\uDF06 bar\'\n}'266 267jsesc([ 'Ich ♥ Bücher', 'foo 𝌆 bar' ], {268 'compact': false,269 'indent': ' '270});271// → '[\n \'Ich \u2665 B\xFCcher\',\n\ t\'foo \uD834\uDF06 bar\'\n]'272```273 274This setting has no effect on the output for strings.275 276#### `indentLevel`277 278The `indentLevel` option takes a numeric value, and defaults to `0`. It represents the current indentation level, i.e. the number of times the value of [the `indent` option](#indent) is repeated.279 280```js281jsesc(['a', 'b', 'c'], {282 'compact': false,283 'indentLevel': 1284});285// → '[\n\t\t\'a\',\n\t\t\'b\',\n\t\t\'c\'\n\t]'286 287jsesc(['a', 'b', 'c'], {288 'compact': false,289 'indentLevel': 2290});291// → '[\n\t\t\t\'a\',\n\t\t\t\'b\',\n\t\t\t\'c\'\n\t\t]'292```293 294#### `json`295 296The `json` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, the output is valid JSON. [Hexadecimal character escape sequences](https://mathiasbynens.be/notes/javascript-escapes#hexadecimal) and [the `\v` or `\0` escape sequences](https://mathiasbynens.be/notes/javascript-escapes#single) are not used. Setting `json: true` implies `quotes: 'double', wrap: true, es6: false`, although these values can still be overridden if needed — but in such cases, the output won’t be valid JSON anymore.297 298```js299jsesc('foo\x00bar\xFF\uFFFDbaz', {300 'json': true301});302// → '"foo\\u0000bar\\u00FF\\uFFFDbaz"'303 304jsesc({ 'foo\x00bar\xFF\uFFFDbaz': 'foo\x00bar\xFF\uFFFDbaz' }, {305 'json': true306});307// → '{"foo\\u0000bar\\u00FF\\uFFFDbaz":"foo\\u0000bar\\u00FF\\uFFFDbaz"}'308 309jsesc([ 'foo\x00bar\xFF\uFFFDbaz', 'foo\x00bar\xFF\uFFFDbaz' ], {310 'json': true311});312// → '["foo\\u0000bar\\u00FF\\uFFFDbaz","foo\\u0000bar\\u00FF\\uFFFDbaz"]'313 314// Values that are acceptable in JSON but aren’t strings, arrays, or object315// literals can’t be escaped, so they’ll just be preserved:316jsesc([ 'foo\x00bar', [1, '©', { 'foo': true, 'qux': null }], 42 ], {317 'json': true318});319// → '["foo\\u0000bar",[1,"\\u00A9",{"foo":true,"qux":null}],42]'320// Values that aren’t allowed in JSON are run through `JSON.stringify()`:321jsesc([ undefined, -Infinity ], {322 'json': true323});324// → '[null,null]'325```326 327**Note:** Using this option on objects or arrays that contain non-string values relies on `JSON.stringify()`. For legacy environments like IE ≤ 7, use [a `JSON` polyfill](http://bestiejs.github.io/json3/).328 329#### `lowercaseHex`330 331The `lowercaseHex` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, any alphabetical hexadecimal digits in escape sequences as well as any hexadecimal integer literals (see [the `numbers` option](#numbers)) in the output are in lowercase.332 333```js334jsesc('Ich ♥ Bücher', {335 'lowercaseHex': true336});337// → 'Ich \\u2665 B\\xfccher'338// ^^339 340jsesc(42, {341 'numbers': 'hexadecimal',342 'lowercaseHex': true343});344// → '0x2a'345// ^^346```347 348### `jsesc.version`349 350A string representing the semantic version number.351 352### Using the `jsesc` binary353 354To use the `jsesc` binary in your shell, simply install jsesc globally using npm:355 356```bash357npm install -g jsesc358```359 360After that you’re able to escape strings from the command line:361 362```bash363$ jsesc 'föo ♥ bår 𝌆 baz'364f\xF6o \u2665 b\xE5r \uD834\uDF06 baz365```366 367To escape arrays or objects containing string values, use the `-o`/`--object` option:368 369```bash370$ jsesc --object '{ "föo": "♥", "bår": "𝌆 baz" }'371{'f\xF6o':'\u2665','b\xE5r':'\uD834\uDF06 baz'}372```373 374To prettify the output in such cases, use the `-p`/`--pretty` option:375 376```bash377$ jsesc --pretty '{ "föo": "♥", "bår": "𝌆 baz" }'378{379 'f\xF6o': '\u2665',380 'b\xE5r': '\uD834\uDF06 baz'381}382```383 384For valid JSON output, use the `-j`/`--json` option:385 386```bash387$ jsesc --json --pretty '{ "föo": "♥", "bår": "𝌆 baz" }'388{389 "f\u00F6o": "\u2665",390 "b\u00E5r": "\uD834\uDF06 baz"391}392```393 394Read a local JSON file, escape any non-ASCII symbols, and save the result to a new file:395 396```bash397$ jsesc --json --object < data-raw.json > data-escaped.json398```399 400Or do the same with an online JSON file:401 402```bash403$ curl -sL "http://git.io/aorKgQ" | jsesc --json --object > data-escaped.json404```405 406See `jsesc --help` for the full list of options.407 408## Support409 410As of v3.0.0, jsesc supports Node.js v6+ only.411 412Older versions (up to jsesc v1.3.0) support Chrome 27, Firefox 3, Safari 4, Opera 10, IE 6, Node.js v6.0.0, Narwhal 0.3.2, RingoJS 0.8-0.11, PhantomJS 1.9.0, and Rhino 1.7RC4. **Note:** Using the `json` option on objects or arrays that contain non-string values relies on `JSON.parse()`. For legacy environments like IE ≤ 7, use [a `JSON` polyfill](https://bestiejs.github.io/json3/).413 414## Author415 416| [](https://twitter.com/mathias "Follow @mathias on Twitter") |417|---|418| [Mathias Bynens](https://mathiasbynens.be/) |419 420## License421 422This library is available under the [MIT](https://mths.be/mit) license.423