Slashes

Add or remove backslashes (escape or unescape).

Getting started

import { addSlashes, removeSlashes } from 'slashes';

addSlashes(`foo\nbar`); // "foo\\nbar"
removeSlashes(`foo\\nbar`); // "foo\nbar"

Adding slashes

By default, addSlashes will escape the following characters.

• Backspace (\b)
• Form Feed (\f)
• Newline (\n)
• Carriage Return (\r)
• Horizontal Tab (\t)
• Vertical Tab (\v)
• Null (\0)
• Double Quote (")
• Backslash (\)

const escaped = addSlashes(`\n`); // "\\n"

This default character set is the characters which cannot be used between double quotes in a JSON string.

const jsonString = `{ "key": "${escaped}" }`;

Custom encoding

Escape encoding can be customized using the getEscaped option.

The following is the default, equivalent to not setting the getEscaped option.

import { getEscapedJsonUnsafe } from 'slashes';

addSlashes(`\n`, { getEscaped: getEscapedJsonUnsafe }); // "\\n"

Included getEscaped implementations:

• getEscapedJsonUnsafe - (Default) Encode characters which cannot be used between double quotes in a JSON string.
• getEscapedAny - Encode ANY character to a single letter (eg. \n) or an ES5 Unicode (eg. \u0100) escape sequence.

A custom getEscaped receives one character (may be Unicode > 2 bytes) at a time. It can return true to use the standard escape sequence, false to not escape the character, or a string to provide a custom escape sequence (must begin with a backslash and be at least 2 characters long).

getEscaped(character: string): boolean | `\\${string}` | ''

Removing slashes

The removeSlashes function will always remove one layer of slashes.

// Handles letter escapes
removeSlashes(`\\n`); // "\n"
// Handles ES6 Unicode Code Point escapes
removeSlashes('\\u{a}'); // "\n"
// Handles ES5 Unicode escapes
removeSlashes('\u000a'); // "\n"
// Handles hex escapes
removeSlashes('\x0a'); // "\n"
// Handles octal escapes
removeSlashes('\12'); // "\n"
// The slash is removed if the escape sequence is invalid
removeSlashes(`\\a`); // "a"

Custom decoding

Although it should generally not be necessary because all escapes are automatically handled, escape decoding can be customized using the getUnescaped option.

The following is the default, equivalent to not setting the getUnescaped option.

import { getUnescapedAny } from 'slashes';

removeSlashes('\\n', { getUnescaped: getUnescapedAny }); // "\n"

Included getUnescaped implementations:

• getUnescapedAny - Decode ANY Javascript supported escape sequence.

A custom getUnescaped implementation receives the escape sequence as the first argument, and the escape sequence code point number or null (for single letter escape sequences) as the second argument. It can return true to use standard decoding, false to treat the sequence as invalid (only removes the leading backslash), or a string to provide a custom decoded value for the escape sequence.

getUnescaped(sequence: `\\${string}`, code: number | null): boolean | string