Lower Case

[![NPM version][npm-image]][npm-url]
[![NPM downloads][downloads-image]][downloads-url]
[![Bundle size][bundlephobia-image]][bundlephobia-url]

> Transform text to lowercase format - all characters converted to lowercase.

🚀 Features

- Lightweight - Only ~200B minified + gzipped
- Type-safe - Full TypeScript support with comprehensive type definitions
- Zero dependencies - No external dependencies
- Tree-shakeable - ES modules support
- Universal - Works in browsers, Node.js, and serverless environments
- Well-tested - Comprehensive test suite with edge cases

📦 Installation

``bash


npm

npm install text-lower-case

yarn

yarn add text-lower-case

pnpm

pnpm add text-lower-case

bun

bun add text-lower-case
`

🎯 Quick Start

`javascript
import { lowerCase } from "text-lower-case";

console.log(lowerCase("HELLO WORLD")); // "hello world"
console.log(lowerCase("CamelCase")); // "camelcase"
console.log(lowerCase("KEBAB-CASE")); // "kebab-case"
`

📖 Usage

$3

`javascript
import { lowerCase } from "text-lower-case";

console.log(lowerCase("HELLO")); // "hello"
`

$3

`javascript
const { lowerCase } = require("text-lower-case");

console.log(lowerCase("HELLO")); // "hello"
`

$3

`typescript
import { lowerCase } from "text-lower-case";

const result: string = lowerCase("HELLO WORLD");
console.log(result); // "hello world"
`

🔄 Transformation Examples

$3

`javascript
import { lowerCase } from "text-lower-case";

// Simple cases
lowerCase("HELLO"); // "hello"
lowerCase("WORLD"); // "world"
lowerCase("Hello World"); // "hello world"

// Mixed case
lowerCase("hELLo WoRLD"); // "hello world"
lowerCase("CamelCase"); // "camelcase"
lowerCase("PascalCase"); // "pascalcase"

// Programming cases
lowerCase("SNAKE_CASE"); // "snake_case"
lowerCase("KEBAB-CASE"); // "kebab-case"
lowerCase("DOT.CASE"); // "dot.case"
`

$3

`javascript
import { lowerCase } from "text-lower-case";

// Empty and single character
lowerCase(""); // ""
lowerCase("A"); // "a"
lowerCase("a"); // "a"

// Numbers and symbols
lowerCase("HELLO123"); // "hello123"
lowerCase("TEST@EMAIL.COM"); // "test@email.com"
lowerCase("USER-123"); // "user-123"

// Unicode characters
lowerCase("CAFÉ"); // "café"
lowerCase("NAÏVE"); // "naïve"
lowerCase("RÉSUMÉ"); // "résumé"
`

🌍 Real-World Examples

$3

`javascript
import { lowerCase } from "text-lower-case";

// Email normalization
lowerCase("USER@EXAMPLE.COM"); // "user@example.com"
lowerCase("John.Doe@Gmail.Com"); // "john.doe@gmail.com"
lowerCase("ADMIN@COMPANY.ORG"); // "admin@company.org"

// Username normalization
lowerCase("JohnDoe123"); // "johndoe123"
lowerCase("ADMIN_USER"); // "admin_user"
lowerCase("Guest-User"); // "guest-user"
`

$3

`javascript
import { lowerCase } from "text-lower-case";

// Domain normalization
lowerCase("EXAMPLE.COM"); // "example.com"
lowerCase("API.GitHub.Com"); // "api.github.com"
lowerCase("SUB.DOMAIN.ORG"); // "sub.domain.org"

// Protocol normalization
lowerCase("HTTPS"); // "https"
lowerCase("HTTP"); // "http"
lowerCase("FTP"); // "ftp"
`

$3

`javascript
import { lowerCase } from "text-lower-case";

function searchItems(items, query) {
const normalizedQuery = lowerCase(query);

return items.filter(
(item) =>
lowerCase(item.name).includes(normalizedQuery) ||
lowerCase(item.description).includes(normalizedQuery),
);
}

const products = [
{ name: "iPhone 15", description: "Latest Apple smartphone" },
{ name: "Samsung Galaxy", description: "Android flagship device" },
{ name: "Google Pixel", description: "Pure Android experience" },
];

console.log(searchItems(products, "APPLE"));
// [{ name: "iPhone 15", description: "Latest Apple smartphone" }]
`

$3

`javascript
import { lowerCase } from "text-lower-case";

function normalizeFormData(formData) {
const normalized = {};

for (const [key, value] of Object.entries(formData)) {
if (typeof value === "string") {
// Normalize email fields
if (key.toLowerCase().includes("email")) {
normalized[key] = lowerCase(value.trim());
}
// Normalize username fields
else if (key.toLowerCase().includes("username")) {
normalized[key] = lowerCase(value.trim());
} else {
normalized[key] = value;
}
} else {
normalized[key] = value;
}
}

return normalized;
}

const formData = {
email: " USER@EXAMPLE.COM ",
username: "JOHNDOE123",
firstName: "John",
lastName: "Doe",
};

console.log(normalizeFormData(formData));
// {
// email: "user@example.com",
// username: "johndoe123",
// firstName: "John",
// lastName: "Doe"
// }
`

$3

`javascript
import { lowerCase } from "text-lower-case";

class UserRepository {
async findByEmail(email) {
const normalizedEmail = lowerCase(email.trim());
return await this.db.users.findOne({
email: normalizedEmail,
});
}

async findByUsername(username) {
const normalizedUsername = lowerCase(username.trim());
return await this.db.users.findOne({
username: normalizedUsername,
});
}

async searchUsers(query) {
const normalizedQuery = lowerCase(query);
return await this.db.users.find({
$or: [
{ email: { $regex: normalizedQuery, $options: "i" } },
{ username: { $regex: normalizedQuery, $options: "i" } },
],
});
}
}
`

$3

`javascript
import { lowerCase } from "text-lower-case";

function parseEnvironmentVariables(env) {
const config = {};

for (const [key, value] of Object.entries(env)) {
// Normalize boolean values
if (typeof value === "string") {
const lowerValue = lowerCase(value);

if (lowerValue === "true" || lowerValue === "false") {
config[key] = lowerValue === "true";
}
// Normalize protocol values
else if (key.toLowerCase().includes("protocol")) {
config[key] = lowerValue;
}
// Normalize host values
else if (key.toLowerCase().includes("host")) {
config[key] = lowerValue;
} else {
config[key] = value;
}
} else {
config[key] = value;
}
}

return config;
}

const env = {
NODE_ENV: "PRODUCTION",
DATABASE_HOST: "LOCALHOST",
USE_SSL: "TRUE",
PROTOCOL: "HTTPS",
};

console.log(parseEnvironmentVariables(env));
// {
// NODE_ENV: "PRODUCTION",
// DATABASE_HOST: "localhost",
// USE_SSL: true,
// PROTOCOL: "https"
// }
`

$3

`javascript
import { lowerCase } from "text-lower-case";

class TextNormalizer {
constructor() {
this.processors = [];
}

addTrim() {
this.processors.push((text) => text.trim());
return this;
}

addLowerCase() {
this.processors.push(lowerCase);
return this;
}

addRemoveExtraSpaces() {
this.processors.push((text) => text.replace(/\s+/g, " "));
return this;
}

process(text) {
return this.processors.reduce(
(result, processor) => processor(result),
text,
);
}
}

const normalizer = new TextNormalizer()
.addTrim()
.addLowerCase()
.addRemoveExtraSpaces();

console.log(normalizer.process(" HELLO WORLD ")); // "hello world"
`

$3

`javascript
import { lowerCase } from "text-lower-case";

function normalizeApiResponse(response) {
if (response.data && Array.isArray(response.data)) {
response.data = response.data.map((item) => {
if (item.email) {
item.email = lowerCase(item.email);
}
if (item.username) {
item.username = lowerCase(item.username);
}
if (item.status) {
item.status = lowerCase(item.status);
}
return item;
});
}

return response;
}

const apiResponse = {
success: true,
data: [
{ id: 1, email: "USER@EXAMPLE.COM", username: "JOHNDOE", status: "ACTIVE" },
{
id: 2,
email: "ADMIN@COMPANY.ORG",
username: "ADMIN",
status: "INACTIVE",
},
],
};

console.log(normalizeApiResponse(apiResponse));
// {
// success: true,
// data: [
// { id: 1, email: "user@example.com", username: "johndoe", status: "active" },
// { id: 2, email: "admin@company.org", username: "admin", status: "inactive" }
// ]
// }
`

📖 API Reference

$3

Converts a string to lowercase format.

#### Parameters

- input (string): The string to transform

#### Returns

- string: The string converted to lowercase

📊 Bundle Size

This package is optimized for minimal bundle size:

- Minified: ~200B
- Gzipped: ~150B
- Tree-shakeable: Yes
- Side effects: None

🌍 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

Type checking

pnpm typecheck

Linting

pnpm lint
`

🔗 Related Packages

- text-camel-case - Convert to camelCase
- text-capital-case - Convert to Capital Case
- text-constant-case - Convert to CONSTANT_CASE
- text-dot-case - Convert to dot.case
- text-header-case - Convert to Header-Case
- text-case - All case transformations in one package

📜 License

MIT © Dmitry Selikhov

🤝 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
- 🐛 Issues: GitHub Issues
- 💬 Discussions: GitHub Discussions
- 📖 Documentation: Full Documentation

---

Made with ❤️ by Dmitry Selikhov

[npm-image]: https://img.shields.io/npm/v/text-lower-case.svg?style=flat
[npm-url]: https://npmjs.org/package/text-lower-case
[downloads-image]: https://img.shields.io/npm/dm/text-lower-case.svg?style=flat
[downloads-url]: https://npmjs.org/package/text-lower-case
[bundlephobia-image]: https://img.shields.io/bundlephobia/minzip/text-lower-case.svg
[bundlephobia-url]: https://bundlephobia.com/result?p=text-lower-case