Returns `true` if text is upper case only.
npm install text-is-upper-case[![NPM version][npm-image]][npm-url]
[![NPM downloads][downloads-image]][downloads-url]
[![Bundle size][bundlephobia-image]][bundlephobia-url]


> Check if a string is in UPPERCASE format.
- 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
``bashnpm
npm install text-is-upper-case
๐ฏ Quick Start
`javascript
import { isUpperCase } from "text-is-upper-case";console.log(isUpperCase("HELLO WORLD")); // true
console.log(isUpperCase("Hello World")); // false
console.log(isUpperCase("hello world")); // false
`๐ Usage
$3
`javascript
import { isUpperCase } from "text-is-upper-case";console.log(isUpperCase("HELLO")); // true
`$3
`javascript
const { isUpperCase } = require("text-is-upper-case");console.log(isUpperCase("HELLO")); // true
`$3
`typescript
import { isUpperCase } from "text-is-upper-case";const result: boolean = isUpperCase("HELLO WORLD");
console.log(result); // true
`๐ Validation Examples
$3
`javascript
import { isUpperCase } from "text-is-upper-case";// Valid uppercase
isUpperCase("HELLO"); // true
isUpperCase("HELLO WORLD"); // true
isUpperCase("TEST123"); // true
isUpperCase("USER_NAME"); // true
isUpperCase("API-KEY"); // true
// Invalid (not uppercase)
isUpperCase("Hello"); // false
isUpperCase("hello"); // false
isUpperCase("Hello World"); // false
isUpperCase("camelCase"); // false
isUpperCase("PascalCase"); // false
`$3
`javascript
import { isUpperCase } from "text-is-upper-case";// Numbers and symbols
isUpperCase("123"); // true
isUpperCase("HELLO123"); // true
isUpperCase("TEST@EMAIL.COM"); // true
isUpperCase("USER_123"); // true
// Empty and whitespace
isUpperCase(""); // true
isUpperCase(" "); // true
isUpperCase("\n\t"); // true
// Special characters
isUpperCase("HELLO-WORLD"); // true
isUpperCase("TEST_CASE"); // true
isUpperCase("FILE.TXT"); // true
`๐ Real-World Examples
$3
`javascript
import { isUpperCase } from "text-is-upper-case";function validateEnvVarName(name) {
if (!isUpperCase(name)) {
return "Environment variable names should be uppercase";
}
return null;
}
console.log(validateEnvVarName("DATABASE_URL")); // null (valid)
console.log(validateEnvVarName("databaseUrl")); // "Environment variable names should be uppercase"
`$3
`javascript
import { isUpperCase } from "text-is-upper-case";function validateConstantName(name) {
if (!isUpperCase(name)) {
return "Constants should be uppercase";
}
return null;
}
console.log(validateConstantName("MAX_RETRIES")); // null
console.log(validateConstantName("maxRetries")); // "Constants should be uppercase"
`$3
`javascript
import { isUpperCase } from "text-is-upper-case";function validateHeaderMethod(method) {
if (!isUpperCase(method)) {
return "HTTP methods should be uppercase";
}
return null;
}
console.log(validateHeaderMethod("GET")); // null
console.log(validateHeaderMethod("get")); // "HTTP methods should be uppercase"
`$3
`javascript
import { isUpperCase } from "text-is-upper-case";function validateConfigConstants(config) {
const invalidKeys = Object.keys(config).filter(
(key) => key.startsWith("CONST_") && !isUpperCase(key),
);
if (invalidKeys.length > 0) {
return
Invalid constant keys (must be uppercase): ${invalidKeys.join(", ")};
}
return null;
}const config1 = { CONST_MAX_SIZE: 100, normalKey: "value" };
const config2 = { CONST_max_size: 100, normalKey: "value" };
console.log(validateConfigConstants(config1)); // null
console.log(validateConfigConstants(config2)); // "Invalid constant keys..."
`๐ API Reference
$3
Checks if a string is in uppercase format.
#### Parameters
-
input (string): The string to check#### Returns
-
boolean: true if the string is uppercase, false otherwise๐ Bundle Size
This package is optimized for minimal bundle size:
- Minified: ~200B
- Gzipped: ~150B
- Tree-shakeable: Yes
- Side effects: None
๐ Browser Support
- Modern browsers: ES2015+ (Chrome 51+, Firefox 54+, Safari 10+)
- Node.js: 12+
- TypeScript: 4.0+
- Bundle formats: UMD, ESM, CommonJS
๐งช Testing
`bash
Run tests
pnpm testRun tests in watch mode
pnpm test --watchRun tests with coverage
pnpm test --coverageType checking
pnpm typecheckLinting
pnpm lint
`๐ 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 package๐ License
๐ค 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`)- ๐ง Email: selikhov.dmitrey@gmail.com
- ๐ Issues: GitHub Issues
- ๐ฌ Discussions: GitHub Discussions
- ๐ Documentation: Full Documentation
---
Made with โค๏ธ by Dmitry Selikhov
[npm-image]: https://img.shields.io/npm/v/text-is-upper-case.svg?style=flat
[npm-url]: https://npmjs.org/package/text-is-upper-case
[downloads-image]: https://img.shields.io/npm/dm/text-is-upper-case.svg?style=flat
[downloads-url]: https://npmjs.org/package/text-is-upper-case
[bundlephobia-image]: https://img.shields.io/bundlephobia/minzip/text-is-upper-case.svg
[bundlephobia-url]: https://bundlephobia.com/result?p=text-is-upper-case