@lacspace/case

Convert strings between cases — camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Title Case & more.

The string-case toolkit — correct on the tricky inputs (acronyms like XMLHttpRequest, numbers like v2, mixed separators, accented unicode). One tiny, typed, dependency-free package instead of a grab-bag of one-function modules.

• 🐫 camelCase · pascalCase — foo_bar → fooBar / FooBar
• 🐍 snakeCase · kebabCase · constantCase — FOO_BAR, foo-bar, foo_bar
• 📝 titleCase · sentenceCase · capitalize · dotCase · pathCase
• 🚂 headerCase / trainCase · capitalCase · noCase
• 🎛️ changeCase(str, name) — pick the case at runtime; words(str) / splitWords(str) are the splitters
• 🔎 isCamelCase, isSnakeCase, … — detect the case (and prove a conversion is a no-op)
• 🌍 Zero dependencies · isomorphic · fully typed

New in 1.1.0 — three more cases (headerCase/trainCase, capitalCase, noCase), a unicode-aware splitWords() that keeps digit groups (v2Point → ["v2","Point"]) and splits acronyms (APIResponse → ["API","Response"]), an opt-in acronym registry (registerAcronyms("API","URL") or per-call { acronyms }) to keep known acronyms upper-cased, and is<Case>() detectors. Fully backward compatible — no existing output changed.

Install

npm install @lacspace/case      # or pnpm add / yarn add / bun add

Use

import { camelCase, snakeCase, kebabCase, constantCase, titleCase, changeCase } from "@lacspace/case";

camelCase("foo_bar-baz");        // "fooBarBaz"
snakeCase("fooBarBaz");          // "foo_bar_baz"
kebabCase("XMLHttpRequest");     // "xml-http-request"
constantCase("fooBar");          // "FOO_BAR"
titleCase("hello_world");        // "Hello World"

changeCase("fooBar", "kebab");   // "foo-bar"   ← pick the case at runtime

import {
  headerCase, capitalCase, noCase, splitWords,
  registerAcronyms, isSnakeCase,
} from "@lacspace/case";

headerCase("foo bar");           // "Foo-Bar"   (Train-Case)
capitalCase("foo_bar");          // "Foo Bar"
noCase("fooBar");                // "foo bar"

splitWords("APIResponse");       // ["API", "Response"]
splitWords("v2Point");           // ["v2", "Point"]  (keeps digit groups)
splitWords("v2Point", { splitOnNumbers: true }); // ["v", "2", "Point"]

// Preserve acronyms (opt-in — defaults unchanged)
pascalCase("apiResponse", { acronyms: ["API"] }); // "APIResponse"
registerAcronyms("API", "URL", "ID");             // or register globally
pascalCase("apiUrl");                             // "APIURL"

isSnakeCase("foo_bar");          // true — already correct, conversion is a no-op

API

| Function | Example | | --- | --- | | camelCase | fooBar | | pascalCase | FooBar | | snakeCase | foo_bar | | kebabCase | foo-bar | | constantCase | FOO_BAR | | dotCase / pathCase | foo.bar / foo/bar | | titleCase / sentenceCase | Foo Bar / Foo bar | | headerCase / trainCase | Foo-Bar | | capitalCase / noCase | Foo Bar / foo bar | | capitalize | Foo | | words(str) | ["foo","bar"] — the splitter behind them all | | splitWords(str, opts?) | unicode-aware splitter; keeps digit groups, splitOnNumbers option | | changeCase(str, name) | runtime case by name (camel,…,header,train,capital,no) | | isCase(str, name) / isCamelCase(str) … | detect whether a string is already in a case | | registerAcronyms(...) / getAcronyms() / clearAcronyms() | manage the global acronym registry |

words() splits on spaces, _ - . /, camelCase boundaries, acronym boundaries and letter/number boundaries — so every conversion is consistent. splitWords() is a unicode-aware alternative that understands accented letters and keeps digit groups (v2) together by default. The acronym-aware converters (camelCase, pascalCase, titleCase, sentenceCase, capitalCase, headerCase) accept an optional { acronyms } and honour the global registry — off by default, so existing output is unchanged.

Licensing

This package is free under the Lacspace Free Licence — permissive freedoms. Use it in personal and commercial projects at no cost; just keep the notice.

Not every Lacspace package is free. We also offer Commercial, Client-specific and Private packages under separate terms — see the Lacspace Licence Centre.

The Lacspace Developer Platform

@lacspace/case is part of 80+ zero-dependency, isomorphic TypeScript packages — one standard library for the modern web. Explore the ecosystem:

• 📦 This package, documented — https://developer.lacspace.com/packages/case
• 🗂️ All 80+ packages — https://developer.lacspace.com/packages
• 🧭 Developer handbook — guides & runnable recipes — https://developer.lacspace.com/handbook
• 🧪 Live playground — run any package in your browser — https://developer.lacspace.com/playground
• 🖥️ Finished app templates — https://templates.lacspace.com
• 🚀 Scaffold a full app — npm create lacspace-app@latest

Free under the Lacspace Free Licence — a permissive, free-to-use licence.