text-case
Version:
Convert text between `camelCase`, `PascalCase`, `Capital Case`, `Header-Case`, `Title Case`, `path/case`, `snake_case`, `param-case`, `kebab-case`, `dot.case`, `CONSTANT_CASE`, `lower case`, `lOWER CASE FIRST`, `UPPER CASE`, `Upper case first` and other
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Markdown
# Text Case
[![NPM version][npm-image]][npm-url]
[![NPM downloads][downloads-image]][downloads-url]
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[](https://opensource.org/licenses/MIT)
[](http://www.typescriptlang.org/)
> **The ultimate text case transformation library** for JavaScript and TypeScript. Convert text between `camelCase`, `PascalCase`, `snake_case`, `kebab-case`, `CONSTANT_CASE`, `Title Case`, `Sentence case`, `dot.case`, `path/case`, `Header-Case`, and many more formats with comprehensive TypeScript support.
## 🚀 Features
- **21 case transformation functions** covering all common text formatting needs
- **Type-safe** with comprehensive TypeScript definitions
- **Zero dependencies** - lightweight and fast
- **Tree-shakeable** - import only what you need
- **Universal** - works in browsers, Node.js, and serverless environments
- **Comprehensive testing** - 100% test coverage with extensive edge cases
- **Professional documentation** - detailed examples and API references
- **Modern tooling** - ES modules, CommonJS, and UMD support
## 📦 Installation
```bash
# npm
npm install text-case
# yarn
yarn add text-case
# pnpm
pnpm add text-case
# bun
bun add text-case
```
## 🎯 Quick Start
```javascript
import {
camelCase, // userProfileData
pascalCase, // UserProfileData
kebabCase, // user-profile-data
snakeCase, // user_profile_data
titleCase, // User Profile Data
sentenceCase, // User profile data
constantCase, // USER_PROFILE_DATA
dotCase, // user.profile.data
pathCase, // user/profile/data
headerCase, // User-Profile-Data
capitalCase, // User Profile Data
noCase, // user profile data
paramCase, // user-profile-data (alias for kebab-case)
upperCase, // USER PROFILE DATA
lowerCase, // user profile data
upperCaseFirst, // User profile data
lowerCaseFirst, // user Profile Data
swapCase, // uSER pROFILE dATA
isUpperCase, // Boolean check
isLowerCase, // Boolean check
} from "text-case";
// Transform any text format
const input = "user_profile_data";
console.log(camelCase(input)); // "userProfileData"
console.log(pascalCase(input)); // "UserProfileData"
console.log(kebabCase(input)); // "user-profile-data"
console.log(titleCase(input)); // "User Profile Data"
```
## 📚 Available Functions
### Core Transformations
| Function | Output Example | Description |
| ---------------- | ------------------- | -------------------------------------------------- |
| `camelCase()` | `userProfileData` | First word lowercase, subsequent words capitalized |
| `pascalCase()` | `UserProfileData` | All words capitalized, no separators |
| `snakeCase()` | `user_profile_data` | Lowercase words separated by underscores |
| `kebabCase()` | `user-profile-data` | Lowercase words separated by hyphens |
| `titleCase()` | `User Profile Data` | All words capitalized, separated by spaces |
| `sentenceCase()` | `User profile data` | First word capitalized, rest lowercase |
### Specialized Formats
| Function | Output Example | Description |
| ---------------- | ------------------- | -------------------------------------------- |
| `constantCase()` | `USER_PROFILE_DATA` | Uppercase words separated by underscores |
| `dotCase()` | `user.profile.data` | Lowercase words separated by dots |
| `pathCase()` | `user/profile/data` | Lowercase words separated by forward slashes |
| `headerCase()` | `User-Profile-Data` | Capitalized words separated by hyphens |
| `capitalCase()` | `User Profile Data` | All words capitalized, separated by spaces |
| `noCase()` | `user profile data` | Lowercase words separated by spaces |
| `paramCase()` | `user-profile-data` | Alias for kebab-case |
### Character Transformations
| Function | Output Example | Description |
| ------------------ | ------------------- | --------------------------- |
| `upperCase()` | `USER PROFILE DATA` | All characters uppercase |
| `lowerCase()` | `user profile data` | All characters lowercase |
| `upperCaseFirst()` | `User profile data` | First character uppercase |
| `lowerCaseFirst()` | `user Profile Data` | First character lowercase |
| `swapCase()` | `uSER pROFILE dATA` | Swap case of all characters |
### Validation Utilities
| Function | Output Example | Description |
| --------------- | -------------- | ---------------------------- |
| `isUpperCase()` | `true/false` | Check if string is uppercase |
| `isLowerCase()` | `true/false` | Check if string is lowercase |
## 🛠️ Advanced Usage
### Custom Options
All transformation functions accept an optional second parameter for customization:
```javascript
import { camelCase, snakeCase } from "text-case";
// Custom word splitting
camelCase("XMLHttpRequest", {
splitRegexp: /([a-z])([A-Z])/g,
}); // "xmlHttpRequest"
// Custom character stripping
snakeCase("hello@world.com", {
stripRegexp: /[@.]/g,
}); // "hello_world_com"
// Custom transformations
camelCase("api-v2-endpoint", {
transform: (word, index) => {
if (word === "api") return "API";
if (word === "v2") return "V2";
return word;
},
}); // "APIV2Endpoint"
```
### TypeScript Support
Full TypeScript support with comprehensive type definitions:
```typescript
import { camelCase, Options } from "text-case";
// Type-safe options
const options: Options = {
splitRegexp: /([a-z])([A-Z])/g,
stripRegexp: /[^a-zA-Z0-9]/g,
transform: (word: string, index: number, words: string[]) =>
word.toLowerCase(),
};
// Type inference
const result: string = camelCase("hello-world", options);
```
### Real-World Examples
#### API Development
```javascript
import { camelCase, snakeCase, kebabCase } from "text-case";
// Convert database columns to JavaScript
const dbUser = {
first_name: "John",
last_name: "Doe",
email_address: "john@example.com",
};
const jsUser = Object.fromEntries(
Object.entries(dbUser).map(([key, value]) => [camelCase(key), value]),
);
// { firstName: "John", lastName: "Doe", emailAddress: "john@example.com" }
// Generate API endpoints
const createEndpoint = (resource, action) =>
`/api/${kebabCase(resource)}/${kebabCase(action)}`;
createEndpoint("UserProfile", "GetById"); // "/api/user-profile/get-by-id"
```
#### React Development
```javascript
import { pascalCase, camelCase } from "text-case";
// Component generation
const createComponent = (name) => `
import React from 'react';
interface ${pascalCase(name)}Props {
${camelCase(name)}Data?: any;
}
export const ${pascalCase(name)}: React.FC<${pascalCase(name)}Props> = ({ ${camelCase(name)}Data }) => {
return <div>{/* ${pascalCase(name)} component */}</div>;
};
`;
console.log(createComponent("user_profile_card"));
```
#### Configuration Management
```javascript
import { constantCase, camelCase } from "text-case";
// Environment variables to config object
const envToConfig = (envVars) => {
return Object.fromEntries(
Object.entries(envVars)
.filter(([key]) => key.startsWith("APP_"))
.map(([key, value]) => [camelCase(key.replace("APP_", "")), value]),
);
};
const env = {
APP_DATABASE_URL: "postgres://...",
APP_API_SECRET_KEY: "secret123",
APP_MAX_FILE_SIZE: "10MB",
};
const config = envToConfig(env);
// { databaseUrl: "postgres://...", apiSecretKey: "secret123", maxFileSize: "10MB" }
```
## 📖 API Reference
### Options Interface
```typescript
interface Options {
// RegExp to split input into words
splitRegexp?: RegExp;
// RegExp to strip unwanted characters
stripRegexp?: RegExp;
// Custom word transformation function
transform?: (word: string, index: number, words: string[]) => string;
// Custom split function (alternative to splitRegexp)
split?: (value: string) => string[];
// Delimiter between words (for spaced formats)
delimiter?: string;
}
```
### Common Patterns
```javascript
// Split on camelCase and PascalCase boundaries
const camelSplit = { splitRegexp: /([a-z])([A-Z])/g };
// Preserve numbers as separate words
const numberSplit = { splitRegexp: /([a-zA-Z])(\d)/g };
// Strip special characters
const stripSpecial = { stripRegexp: /[^a-zA-Z0-9]/g };
// Custom acronym handling
const acronymTransform = {
transform: (word) => {
const acronyms = ["API", "URL", "HTTP", "JSON", "XML"];
return acronyms.includes(word.toUpperCase()) ? word.toUpperCase() : word;
},
};
```
## 📊 Bundle Size
This package is optimized for minimal bundle size:
- **Minified**: ~8KB (all functions)
- **Gzipped**: ~3KB (all functions)
- **Tree-shakeable**: Yes
- **Side effects**: None
For even smaller bundles, consider using individual packages:
```javascript
// ❌ Imports entire library (~8KB)
import { camelCase } from "text-case";
// ✅ Imports only camelCase (~450B)
import { camelCase } from "text-camel-case";
```
## 🌍 Browser Support
- **Modern browsers**: ES2015+ (Chrome 51+, Firefox 54+, Safari 10+)
- **Node.js**: 12+
- **TypeScript**: 4.0+
- **Bundle formats**: UMD, ESM, CommonJS
## 🧪 Testing
```bash
# Run tests
pnpm test
# Run tests in watch mode
pnpm test --watch
# Run tests with coverage
pnpm test --coverage
```
## 🔗 Individual Packages
For optimal bundle size, you can install individual packages:
- [`text-camel-case`](https://www.npmjs.com/package/text-camel-case) - camelCase transformation
- [`text-pascal-case`](https://www.npmjs.com/package/text-pascal-case) - PascalCase transformation
- [`text-snake-case`](https://www.npmjs.com/package/text-snake-case) - snake_case transformation
- [`text-kebab-case`](https://www.npmjs.com/package/text-kebab-case) - kebab-case transformation
- [`text-title-case`](https://www.npmjs.com/package/text-title-case) - Title Case transformation
- [`text-sentence-case`](https://www.npmjs.com/package/text-sentence-case) - Sentence case transformation
- [`text-constant-case`](https://www.npmjs.com/package/text-constant-case) - CONSTANT_CASE transformation
- [`text-dot-case`](https://www.npmjs.com/package/text-dot-case) - dot.case transformation
- [`text-path-case`](https://www.npmjs.com/package/text-path-case) - path/case transformation
- [`text-header-case`](https://www.npmjs.com/package/text-header-case) - Header-Case transformation
- [`text-capital-case`](https://www.npmjs.com/package/text-capital-case) - Capital Case transformation
- [`text-no-case`](https://www.npmjs.com/package/text-no-case) - no case transformation
- [`text-param-case`](https://www.npmjs.com/package/text-param-case) - param-case transformation
- [`text-upper-case`](https://www.npmjs.com/package/text-upper-case) - UPPER CASE transformation
- [`text-lower-case`](https://www.npmjs.com/package/text-lower-case) - lower case transformation
- [`text-upper-case-first`](https://www.npmjs.com/package/text-upper-case-first) - Upper case first transformation
- [`text-lower-case-first`](https://www.npmjs.com/package/text-lower-case-first) - lower case first transformation
- [`text-swap-case`](https://www.npmjs.com/package/text-swap-case) - sWaP cAsE transformation
- [`text-is-upper-case`](https://www.npmjs.com/package/text-is-upper-case) - UPPER CASE validation
- [`text-is-lower-case`](https://www.npmjs.com/package/text-is-lower-case) - lower case validation
## 📜 License
[MIT](LICENSE) © [Dmitry Selikhov](https://github.com/idimetrix)
## 🤝 Contributing
1. Fork the repository
2. Create your feature branch (`git checkout -b feature/amazing-feature`)
3. Commit your changes (`git commit -m 'Add some amazing feature'`)
4. Push to the branch (`git push origin feature/amazing-feature`)
5. Open a Pull Request
## 🆘 Support
- 📧 **Email**: [selikhov.dmitrey@gmail.com](mailto:selikhov.dmitrey@gmail.com)
- 🐛 **Issues**: [GitHub Issues](https://github.com/idimetrix/text-case/issues)
- 💬 **Discussions**: [GitHub Discussions](https://github.com/idimetrix/text-case/discussions)
---
**Made with ❤️ by [Dmitry Selikhov](https://github.com/idimetrix)**
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[npm-url]: https://npmjs.org/package/text-case
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[bundlephobia-url]: https://bundlephobia.com/result?p=text-case