string

DIACRITICS

A map of base characters to their diacritic variants, used by makeDiacriticPattern.

string.DIACRITICS = {
  a: 'aáàäâã',
  e: 'eéëèê',
  i: 'iíïìî',
  o: 'oóöòõô',
  u: 'uüúùû',
  c: 'cç'
}

normalize

Signature

string.normalize(str, options = {})

Description

Normalizes a string by optionally collapsing whitespace, stripping diacritics, and lowercasing. Transformations are applied in order: spaces → diacritics → case.

Parameters

Name	Type	Required	Description
str	string	yes	The string to normalize
options	object	no	Normalization options
options.ignoreSpaces	boolean	no	Collapse consecutive whitespace and trim. Defaults to false
options.ignoreDiacritics	boolean	no	Strip diacritics using NFKD decomposition. Defaults to false
options.ignoreCase	boolean	no	Convert to lowercase. Defaults to false
options.locale	string	no	Locale passed to toLocaleLowerCase (e.g. 'fr-FR'). Defaults to system locale

Returns

Type	Description
string	The normalized string

Throws

Throws a TypeError if str is not a string.

Examples

string.normalize('  Héllo   World  ', { ignoreSpaces: true })
// 'Héllo World'

string.normalize('éàü', { ignoreDiacritics: true })
// 'eau'

string.normalize('Hello', { ignoreCase: true })
// 'hello'

string.normalize('  Héllo  ', { ignoreSpaces: true, ignoreDiacritics: true, ignoreCase: true })
// 'hello'

makeDiacriticPattern

Signature

string.makeDiacriticPattern(pattern, options = {})

Description

Converts a string into a regex-compatible pattern where each character is expanded to match all its diacritic variants. Useful for building case/accent-insensitive search patterns.

By default (reverse: false), only base characters (e.g. a) are expanded to their variants ([aáàäâã]). With reverse: true, any diacritic variant in the pattern is also expanded.

Parameters

Name	Type	Required	Description
pattern	string	yes	The string to convert into a diacritic pattern
options	object	no	Options
options.reverse	boolean	no	If true, expands diacritic variants back to their family. Defaults to false

Returns

Type	Description
string	A regex-compatible pattern string

Throws

Throws a TypeError if pattern is not a string.

Examples

string.makeDiacriticPattern('cafe')
// 'c[cç][aáàäâã]f[eéëèê]'

string.makeDiacriticPattern('café', { reverse: true })
// 'c[cç][aáàäâã]f[eéëèê]'

// Use in a regex
const pattern = string.makeDiacriticPattern('cafe')
new RegExp(pattern, 'i').test('Café') // true

slugify

Signature

string.slugify(str, separator = '-')

Description

Converts a string into a URL-friendly slug by stripping diacritics, lowercasing, and replacing non-alphanumeric characters with a separator. Leading and trailing separators are removed.

Parameters

Name	Type	Required	Description
str	string	yes	The string to slugify
separator	string	no	A single character used as separator. Defaults to '-'

Returns

Type	Description
string	The slugified string

Throws

Throws a TypeError if str is not a string or if separator is not a single character.

Examples

string.slugify('Hello World')
// 'hello-world'

string.slugify('Héllo Wörld')
// 'hello-world'

string.slugify('  Hello   World  ')
// 'hello-world'

string.slugify('Hello World', '_')
// 'hello_world'

initials

Signature

string.initials(str, options = {})

Description

Extracts the initials of a string by taking the first character of each word, uppercased.

Parameters

Name	Type	Required	Description
str	string	yes	The string to extract initials from
options	object	no	Options
options.max	number	no	Maximum number of initials to return

Returns

Type	Description
string	The initials, uppercased and concatenated

Throws

Throws a TypeError if str is not a string.

Examples

string.initials('John Doe')                        // 'JD'
string.initials('Jean Pierre Dupont')              // 'JPD'
string.initials('Jean Pierre Dupont', { max: 2 }) // 'JP'
string.initials('john doe')                        // 'JD'