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# is-unicode-supported
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is-unicode-supported is a lightweight utility library for detecting whether the current terminal environment supports Unicode characters. It provides platform-specific logic to determine Unicode support by checking environment variables and terminal identifiers, making it ideal for command-line tools and CLI applications that need to decide between Unicode symbols and ASCII fallbacks.
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## Package Information
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- **Package Name**: is-unicode-supported
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- **Package Type**: npm
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- **Language**: JavaScript (ES modules)
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- **Installation**: `npm install is-unicode-supported`
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## Core Imports
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```javascript
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import isUnicodeSupported from 'is-unicode-supported';
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```
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**Note**: This package is ESM-only and requires Node.js 12+ with ES module support. CommonJS `require()` is not supported.
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## Basic Usage
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```javascript
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import isUnicodeSupported from 'is-unicode-supported';
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const supportsUnicode = isUnicodeSupported();
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if (supportsUnicode) {
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    console.log('✅ Unicode is supported - using fancy symbols');
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} else {
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    console.log('[OK] Unicode not supported - using ASCII fallbacks');
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}
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```
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## Capabilities
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### Unicode Detection
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Detects whether the terminal supports Unicode by examining platform-specific environment variables and terminal identifiers.
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```javascript { .api }
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/**
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 * Detect whether the terminal supports Unicode
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 * @returns {boolean} true if the terminal supports Unicode, false otherwise
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 */
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function isUnicodeSupported(): boolean;
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```
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**Detection Logic:**
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For **non-Windows platforms** (macOS, Linux, etc.):
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- Returns `true` by default
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- Returns `false` only if `process.env.TERM === 'linux'` (Linux console kernel)
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For **Windows platforms**:
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- Returns `true` if any of the following conditions are met:
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  - `process.env.CI` is truthy (CI environments)
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  - `process.env.WT_SESSION` is truthy (Windows Terminal)
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  - `process.env.TERMINUS_SUBLIME` is truthy (Terminus < v0.2.27)
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  - `process.env.ConEmuTask === '{cmd::Cmder}'` (ConEmu and cmder)
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  - `process.env.TERM_PROGRAM === 'Terminus-Sublime'`
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  - `process.env.TERM_PROGRAM === 'vscode'` (VS Code integrated terminal)
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  - `process.env.TERM === 'xterm-256color'`
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  - `process.env.TERM === 'alacritty'`
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  - `process.env.TERMINAL_EMULATOR === 'JetBrains-JediTerm'`
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- Returns `false` if none of the above conditions are met
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**Usage Examples:**
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```javascript
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import isUnicodeSupported from 'is-unicode-supported';
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// Simple check
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if (isUnicodeSupported()) {
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    console.log('🎉 Unicode supported!');
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} else {
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    console.log('Unicode not supported');
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}
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// CLI output decision
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const checkMark = isUnicodeSupported() ? '✅' : '[OK]';
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const crossMark = isUnicodeSupported() ? '❌' : '[FAIL]';
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console.log(`${checkMark} Test passed`);
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console.log(`${crossMark} Test failed`);
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// Progress indicators
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const spinner = isUnicodeSupported() ? ['⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'] : ['|', '/', '-', '\\'];
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```
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## Platform Support
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- **Node.js**: 12+ (ES modules support required)
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- **Windows**: Detects specific terminal environments that support Unicode
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- **macOS/Linux**: Assumes Unicode support except for Linux console kernel
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- **CI Environments**: Automatically detects CI systems that support Unicode
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## Dependencies
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No runtime dependencies. Uses only Node.js built-in modules:
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- `node:process` for platform detection and environment variable access