stacks-strings

name	stacks-strings
description	Use when working with string utilities in Stacks — case conversion (camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Train-Case, etc.), pluralization, string validation (email, URL, UUID, credit card, etc.), slug generation, random strings, template interpolation, or the Str facade. Covers @stacksjs/strings.
license	MIT
compatibility	Bun >= 1.3.0, TypeScript
allowed-tools	Read Edit Write Bash Grep Glob

Stacks Strings

Key Paths

• Core package: storage/framework/core/strings/src/
• Package: @stacksjs/strings
• Entry: storage/framework/core/strings/src/string.ts (re-exports all submodules)

Architecture

The package re-exports from these submodules:

• case.ts — case conversion functions (camelCase, pascalCase, snakeCase, etc.)
• pluralize.ts — English pluralization/singularization with rule engine
• slug.ts — URL slug generation with extensive character map
• utils.ts — random strings, template interpolation, slash, prefix/suffix, truncate, detect-indent, detect-newline
• macro.ts — Str and str facade objects
• validators.ts — re-exports from is.ts (native string validators)
• sponge-case.ts — random upper/lower case
• swap-case.ts — swap upper/lower case
• title-case.ts — intelligent title case with small word handling

The top-level index.ts does:

export * from './string'
export * as string from './string'

And string.ts does:

export * from './case'
export * from './helpers'
export * from './macro'
export * from './pluralize'
export * from './slug'
export * from './utils'
export * from './validators'

Case Conversion Functions

All accept (input: string, options?: CaseOptions) and use Unicode-aware word boundary detection via regex patterns (\p{Ll}, \p{Lu}).

interface CaseOptions {
  locale?: string[] | string | false | undefined
  split?: (value: string) => string[]
  delimiter?: string
  prefixCharacters?: string   // characters to preserve as prefix
  suffixCharacters?: string   // characters to preserve as suffix
}

interface PascalCaseOptions extends CaseOptions {
  mergeAmbiguousCharacters?: boolean
}

Functions

camelCase('hello world')        // 'helloWorld'  — first word lowercase, rest capitalized
pascalCase('hello world')       // 'HelloWorld'  — all words capitalized
snakeCase('hello world')        // 'hello_world' — alias for noCase with '_' delimiter
kebabCase('hello world')        // 'hello-world' — alias for noCase with '-' delimiter
constantCase('hello world')     // 'HELLO_WORLD' — all uppercase with '_' delimiter
trainCase('hello world')        // 'Hello-World' — capitalCase with '-' delimiter
dotCase('hello world')          // 'hello.world' — noCase with '.' delimiter
pathCase('hello world')         // 'hello/world' — noCase with '/' delimiter
sentenceCase('hello world')     // 'Hello world' — first word capitalized, rest lowercase
capitalCase('hello world')      // 'Hello World' — all words capitalized, space delimiter
noCase('helloWorld')            // 'hello world' — lowercase with space delimiter
pascalSnakeCase('hello world')  // 'Hello_World' — capitalCase with '_' delimiter
paramCase('hello world')        // 'hello-world' — alias for kebabCase

Special Case Functions

spongeCase('hello world')       // 'hElLo wOrLd' — random upper/lower per character
spongeCase('hello', 'en')       // accepts optional locale

swapCase('Hello')               // 'hELLO' — swaps each character's case
swapCase('Hello', 'en')         // accepts optional locale

Title Case

titleCase('hello world')                          // 'Hello World'
titleCase('the quick brown fox')                  // 'The Quick Brown Fox'
titleCase('the quick brown fox', { sentenceCase: true })  // 'The quick brown fox'

interface TitleCaseOptions {
  locale?: string | string[]
  sentenceCase?: boolean                 // only capitalize first word + after terminators
  sentenceTerminators?: Set<string>      // default: '.', '!', '?'
  titleTerminators?: Set<string>         // default: '.', '!', '?', ':', '"', "'", '"'
  smallWords?: Set<string>               // words not capitalized (see SMALL_WORDS)
  wordSeparators?: Set<string>           // default: '---', '--', '-', '---', '/'
}

Handles special cases: URLs, email addresses, acronyms (e.g., "U.S.A."), camelCase words (e.g., "iPhone"), and hyphenated compound words.

Word Splitting

split('camelCase')              // ['camel', 'Case']
split('hello_world')            // ['hello', 'world']
split('HTTPSRequest')           // ['HTTPS', 'Request']
splitSeparateNumbers('test123') // ['test', '123']

Uses Unicode-aware regex for word boundary detection. Handles camelCase, PascalCase, snake_case, UPPER_CASE, and mixed formats.

Pluralization

Full English pluralization engine with irregular words, custom rules, and uncountable nouns.

import { plural, singular, pluralize } from '@stacksjs/strings'

// Basic usage
plural('person')                        // 'people'
plural('person', 1)                     // 'person'  (count-aware)
singular('people')                      // 'person'

// Pluralize function with options
pluralize('mouse')                      // 'mice'
pluralize('mouse', { count: 1 })        // 'mouse'
pluralize('mouse', { count: 2 })        // 'mice'
pluralize('mouse', { count: 5, inclusive: true })  // '5 mice'

// Boolean checks
pluralize.isPlural('dogs')              // true
pluralize.isSingular('dog')             // true

// Custom rules
pluralize.addPluralRule(/gex$/i, 'gices')
pluralize.addSingularRule(/gices$/i, 'gex')
pluralize.addIrregularRule(, )
pluralize.()

Built-in Irregular Words

The engine includes 48 irregular word pairs (e.g., ox/oxen, foot/feet, goose/geese, child/children, person/people, die/dice, tooth/teeth, quiz/quizzes, etc.).

Built-in Uncountable Words

Includes 74 uncountable words (e.g., sheep, fish, moose, aircraft, software, equipment, information, etc.) plus regex patterns for Pokemon, words ending in non-ASCII ese, deer, fish, measles, pox, sheep.

Case Preservation

The pluralization engine preserves the case pattern of the input word:

• 'PERSON' -> 'PEOPLE'
• 'Person' -> 'People'
• 'person' -> 'people'

Slug Generation

Two slug functions with different defaults:

slug(str, options?) — Simple slug (strict + lowercase by default)

slug('Hello World')              // 'hello-world'
slug('Hello World', { lower: false })  // 'Hello-World'

slugify(str, options?) — Full-featured slug

slugify('Hello World!')          // 'Hello-World!'  (not strict/lowercase by default)
slugify('Hello World!', { lower: true, strict: true })  // 'hello-world'

interface SlugifyOptions {
  replacement?: string    // default: '-'
  remove?: RegExp         // chars to remove (default: /[^\w\s$*+~.()'"!\-:@]+/g)
  lower?: boolean         // default: false
  strict?: boolean        // strip non-alphanumeric (default: false)
  locale?: string         // locale-specific char mapping
  trim?: boolean          // trim result (default: true)
}

Character Map

Extensive built-in character map covering:

• Latin extended (accented chars): A-Z with diacritics
• Greek alphabet
• Cyrillic alphabet
• Armenian alphabet
• Arabic alphabet and numerals
• Georgian alphabet
• Vietnamese diacritics
• Currency symbols ($, EUR, GBP, YEN, etc.)
• Special characters (trademark, copyright, etc.)

Locale Support

Locale-specific character mappings for: bg, de, es, fr, pt, uk, vi, da, nb, it, nl, sv.

slugify('AE', { locale: 'de' })  // 'AE' (German)
slugify('AE')                     // 'A'  (default)

Extending the Character Map

extendCharMap({ 'EUR': 'EUR', 'GBP': 'GBP' })

String Utilities

capitalize('hello world')                  // 'Hello world' — first char upper, rest lower
lowercase('HELLO')                         // 'hello'
slash('path\\to\\file')                    // 'path/to/file'
ensurePrefix('https://', 'google.com')     // 'https://google.com'
ensurePrefix('https://', 'https://x.com') // 'https://x.com' (already has prefix)
ensureSuffix('.ts', 'file')                // 'file.ts'
ensureSuffix('.ts', 'file.ts')             // 'file.ts' (already has suffix)
template('Hello {0}! My name is {1}.', 'Buddy', 'Chris')  // 'Hello Buddy! My name is Chris.'
truncate('long text here', 10, '...')      // 'long te...'
truncate('short', 10)                      // 'short' (no truncation needed)
random()                                    // 16-char random string (nanoid-style)
random(21)                                  // 21-char random string
random(10, )                           

urlAlphabet Constant

// 64 URL-safe characters used by random() by default
const urlAlphabet = 'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict'

String Validators

Native TypeScript implementations (no external validator dependency). All accept a string and return boolean.

Core Validators

isEmail('[e-mail]')               // true -- regex: /^[^\s@]+@[^\s@]+\.[^\s@]+$/
isStrongPassword('Abc123!@#')             // true -- min 8 chars, upper, lower, digit, symbol
isAlphanumeric('abc123')                  // true -- /^[a-zA-Z0-9]+$/
isAlpha('abcdef')                         // true -- /^[a-zA-Z]+$/
isNumeric('123')                          // true -- /^[0-9]+$/ (whole numbers only)
isURL('https://example.com')              // true -- uses URL constructor, requires http(s) protocol

Format Validators

isHexColor('#ff0000')                     // true -- 3 or 6 hex digits with #
isHexadecimal('deadbeef')                 // true -- hex chars only
isBase64('SGVsbG8=')                      // true -- btoa(atob(x)) === x
isBase32('MFZWI===')                      // true -- /^[A-Z2-7]+=*$/
isAscii('hello')                          // true -- /^[\x00-\x7F]*$/
isJSON('{"key":"value"}')                 // true -- JSON.parse succeeds
isHSL('hsl(0, 100%, 50%)')               // true
isMimeType('text/html')                   // true -- /^[a-z]+\/[a-z0-9\-+.]+$/i
isDataURI('data:text/plain;base64,...')   // true
isJWT('eyJhbGciOi...')                    // true -- 3 dot-separated base64url segments

Network Validators

isIP('192.168.1.1')                       // true -- IPv4 and IPv6
isIPRange('192.168.1.0/24')               // true -- CIDR notation (IPv4: 0-32, IPv6: 0-128)
isMACAddress('00:11:22:33:44:55')         // true -- colon or hyphen separated
isFQDN('example.com')                     // true -- fully qualified domain name

Financial Validators

isCreditCard('4111111111111111')           // true -- Luhn algorithm, 13-19 digits
isISBN('978-3-16-148410-0')               // true -- ISBN-10 and ISBN-13 with checksum
isCurrency('$1,234.56')                   // true -- supports $, GBP, EUR, YEN
isIBAN('DE89370400440532013000')           // true -- mod 97 check
isISIN('US0378331005')                     // true -- Luhn algorithm
isISSN('0378-5955')                        // true -- mod 11 check

Geographic Validators

isLatLong('40.7128,-74.0060')             // true -- lat: -90..90, long: -180..180
isLatitude('40.7128')                     // true
isLongitude('-74.0060')                   // true
isPostalCode('12345')                     // true -- US, UK, Canada, generic formats

Phone, Identity, Date Validators

isMobilePhone('[phone]')              // true -- international format, min 7 digits
isUUID('550e8400-e29b-41d4-a716...')      // true -- v1-v5
isISO8601('2024-01-01T00:00:00Z')         // true -- with Date validity check
isIdentityCard('AB123456')                // true -- generic 5-20 alphanumeric
isISRC('USRC17607839')                    // true
isISO31661Alpha2('US')                    // true
isISO31661Alpha3('USA')                   // true
validateUsername('user123')               // true -- alias for isAlphanumeric
isHash('abc123...', 'md5')               // true -- supports md5(32), sha1(40), sha256(64), sha384(96), sha512(128)
isByteLength('hello', { min: 1, max: 10 }) // true
isFullWidth('\uFF21')                     // true
isHalfWidth('a')                          // true

Newline & Indentation Detection

Newline Detection (from detect-newline.ts)

detectNewline('line1\r\nline2')          // '\r\n'
detectNewline('line1\nline2')            // '\n'
detectNewline('no newline')              // undefined
detectNewlineGraceful(text)              // '\n' (fallback when no newline found)

The detection counts CRLF vs LF occurrences and returns the dominant type.

Indentation Detection (from detect-indent.ts)

detectIndent('  hello\n    world')
// { amount: 2, type: 'space', indent: '  ' }

detectIndent('\thello\n\t\tworld')
// { amount: 1, type: 'tab', indent: '\t' }

detectIndent('no indent')
// { amount: 0, type: undefined, indent: '' }

Algorithm: builds a frequency map of indent changes (type + size), handles edge cases like single-space indentation (skipped by default to avoid false positives from code comments), then selects the most common indent pattern.

Str Facade Object

Both Str and str are exported as equivalent facade objects providing all functions as methods.

import { Str, str } from '@stacksjs/strings'

// Case conversion
Str.camelCase('hello world')      // 'helloWorld'
Str.pascalCase('hello world')     // 'HelloWorld'
Str.snakeCase('hello world')      // 'hello_world'
Str.kebabCase('hello world')      // 'hello-world'
Str.constantCase('hello world')   // 'HELLO_WORLD'
Str.dotCase('hello world')        // 'hello.world'
Str.noCase('helloWorld')          // 'hello world'
Str.paramCase('hello world')      // 'hello-world'
Str.pathCase('hello world')       // 'hello/world'
Str.sentenceCase('hello world')   // 'Hello world'
Str.capitalCase('hello world')    // 'Hello World'
Str.()      


.()           
.()           
.()                    
.(, )             
.(, , )  
.(, )      
.()             
.(, )     
.(, )   
.(text)            
.(text)           


.()              
.()            
.()              
.()             
.(, )
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.(, )
.()

Exported Constants

// From title-case.ts
WORD_SEPARATORS: Set<string>      // '---', '--', '-', '---', '/'
SENTENCE_TERMINATORS: Set<string> // '.', '!', '?'
TITLE_TERMINATORS: Set<string>    // '.', '!', '?', ':', '"', "'", '"'
SMALL_WORDS: Set<string>          // 'a', 'an', 'and', 'as', 'at', 'because', 'but', 'by',
                                  // 'en', 'for', 'if', 'in', 'neither', 'nor', 'of', 'on',
                                  // 'only', 'or', 'over', 'per', 'so', 'some', 'than', 'that',
                                  // 'the', 'to', 'up', 'upon', 'v', 'versus', 'via', 'vs',
                                  // 'when', 'with', 'without', 'yet'

// From utils.ts
urlAlphabet: string               // 64 URL-safe chars for random()

Exported Types

type Locale = string[] | string | false | undefined
interface CaseOptions { locale?, split?, delimiter?, prefixCharacters?, suffixCharacters? }
interface PascalCaseOptions extends CaseOptions { mergeAmbiguousCharacters? }
interface TitleCaseOptions { locale?, sentenceCase?, sentenceTerminators?, smallWords?, titleTerminators?, wordSeparators? }
interface SlugifyOptions { replacement?, remove?, lower?, strict?, locale?, trim? }
interface PluralizeOptions { count?, inclusive? }

Gotchas

• Case conversion uses Unicode-aware word boundary detection (\p{Ll}, \p{Lu}) -- handles international characters
• slug() calls slugify() under the hood but defaults to { lower: true, strict: true }; slugify() defaults to { lower: false, strict: false }
• pascalCase and camelCase accept PascalCaseOptions with mergeAmbiguousCharacters to control number-prefixed word handling
• All case functions support prefixCharacters/suffixCharacters to preserve leading/trailing non-word characters
• pluralize() is both a function AND an object with methods -- pluralize.plural(), pluralize.singular(), etc.
• The random() function uses Math.random(), not crypto -- fine for IDs but not for security tokens
• isNumeric() only matches whole numbers (/^\d+$/), not floats -- use parseFloat for float checking
• isURL() requires http: or https: protocol -- rejects other protocols and bare domains
• The Str facade does NOT include validators -- only case, utility, and pluralization methods
• helpers.ts only exports toString() which returns Object.prototype.toString.call(v)