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Sepehr Mohseni
Sepehr Mohseni

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Introducing strfi: The Ultimate String Utility Library for JavaScript & TypeScript

#javascript #typescript #node

I'm thrilled to announce strfi – a comprehensive, zero-dependency, tree-shakeable collection of over 150 pure string utilities for modern JavaScript and TypeScript projects.

Tired of pulling in heavy libraries for simple string tasks like slugifying text, escaping HTML, calculating edit distance, or formatting bytes? strfi is here to be your lightweight, yet incredibly powerful string toolkit.

Key Highlights

  • Zero runtime dependencies
  • Fully tree-shakeable – import only the functions you need
  • Excellent TypeScript support with precise types
  • Unicode-aware and locale-sensitive where applicable
  • No unsafe practices (no eval(), etc.)
  • Tiny minified bundle: ~22KB
  • Works everywhere: Node.js 16+, modern browsers, Deno, Bun, React Native, Cloudflare Workers

Installation 

npm install strfi
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Or with yarn/pnpm:

yarn add strfi
# or
pnpm add strfi
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Quick Usage Examples: 

import { 
  slugify, 
  escapeHtml, 
  capitalize, 
  levenshteinDistance, 
  formatBytes,
  camelCase,
  truncate,
  isEmail
} from 'strfi';

console.log(slugify('Hello World! 🚀'));           // "hello-world"
console.log(escapeHtml('<script>alert("xss")</script>')); // "&lt;script&gt;alert(&quot;xss&quot;)&lt;/script&gt;"
console.log(capitalize('javascript'));             // "Javascript"
console.log(levenshteinDistance('kitten', 'sitting')); // 3
console.log(formatBytes(1500000));                 // "1.43 MB"
console.log(camelCase('foo-bar_baz'));             // "fooBarBaz"
console.log(truncate('Very long text here', { length: 10 })); // "Very lo..."
console.log(isEmail('test@example.com'));          // true
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All Features – Grouped by Category
strfi provides an extensive set of utilities, organized into clear categories:

Case Transformations

toUpperCase, toLowerCase, capitalize, uncapitalize, titleCase, camelCase, pascalCase, snakeCase, kebabCase, constantCase, dotCase, pathCase, sentenceCase, swapCase, isUpperCase, isLowerCase, isTitleCase
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Whitespace Operations

trim, trimStart, trimEnd, trimChars, trimCharsStart, trimCharsEnd, collapseWhitespace, removeWhitespace, padStart, padEnd, center, repeat, insert, removeAt, indent, dedent
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String Manipulation

reverse, truncate, truncateMiddle, wordWrap, slugify, between, betweenAll, remove, replaceFirst, replaceLast, replaceAll, mask, shuffle, chunk, splitBy, join, stripTags, normalizeLineEndings, surround, ensurePrefix, ensureSuffix, removePrefix, removeSuffix, lines, first, last
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String Validation

isBlank, isNotBlank, isEmpty, isNotEmpty, isAlpha, isAlphanumeric, isNumeric, isInteger, isDecimal, isAscii, isPrintableAscii, isHexadecimal, isUUID, isEmail, isURL, isJSON, isIPv4, isIPv6, isCreditCard, isSlug, startsWith, endsWith, contains, containsAll, containsAny, matches, compare, equals, equalsIgnoreCase, isPalindrome, isWhitespace, hasUpperCase, hasLowerCase, hasDigits, hasSpecialChars
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Encoding & Escaping

escapeHtml, unescapeHtml, escapeXml, unescapeXml, escapeRegex, escapeSqlLike, escapeShell, toBase64, fromBase64, toBase64Url, fromBase64Url, encodeUrl, decodeUrl, toHex, fromHex, toAsciiCodes, fromAsciiCodes, rot13
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Search & Analysis

countOccurrences, countWords, countLines, countSentences, countParagraphs, charFrequency, wordFrequency, indicesOf, nthIndexOf, extractNumbers, extractWords, extractEmails, extractUrls, extractHashtags, extractMentions, levenshteinDistance, similarity, longestCommonSubstring, longestCommonPrefix, longestCommonSuffix
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Unicode & i18n

normalize, removeDiacritics, toCodePoints, fromCodePoints, graphemeLength, toGraphemes, toWords, isLetter, isDigit, isSpace, isPunctuation, isRTL, isLTR, getDirection, formatNumber, formatDate, formatCurrency, formatRelativeTime, pluralize, collate, getLocaleDisplayName, getRegionDisplayName
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Formatting & Utilities

template, format, formatNamed, sprintf, zeroPad, formatThousands, formatBytes, formatDuration, ordinal, loremIpsum, randomString, uuid, hashCode
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What's Next?
This is v1.0.0 – packed with features from day one! I'm planning more i18n enhancements, performance optimizations, and community-driven utilities.
Contributions, bug reports, and feature requests are very welcome!
Links

npm: https://www.npmjs.com/package/strfi
GitHub Profile: https://github.com/sepehr-mohseni/strfi

If you give strfi a try, let me know in the comments – what's your favorite utility? Any missing feature you'd love?
Stars, feedback, and shares are hugely appreciated. Thank you! 🚀
Happy coding!

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