clitutor/src/utils/helpers.js

Interactive CLI learning tool for beginners

const chalk = require('chalk');
const readline = require('readline');

function clearScreen() {
  process.stdout.write('\x1Bc');
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

function printWithTypingEffect(text, delay = 30) {
  return new Promise((resolve) => {
    let i = 0;
    let skipAnimation = false;
    
    // Set up stdin for raw mode to capture single keypresses
    if (process.stdin.isTTY) {
      process.stdin.setRawMode(true);
      process.stdin.resume();
    }
    
    // Listen for Enter key
    const keypressHandler = (chunk) => {
      // Enter key is '\r' or '\n' in raw mode
      if (chunk && (chunk.toString() === '\r' || chunk.toString() === '\n')) {
        skipAnimation = true;
      }
    };
    
    process.stdin.on('data', keypressHandler);
    
    const cleanup = () => {
      // Remove the keypress listener
      process.stdin.removeListener('data', keypressHandler);
      
      // Restore stdin to normal mode
      if (process.stdin.isTTY) {
        process.stdin.setRawMode(false);
        process.stdin.pause();
      }
    };
    
    const interval = setInterval(() => {
      if (skipAnimation && i < text.length) {
        // Print remaining text immediately
        process.stdout.write(text.substring(i));
        clearInterval(interval);
        process.stdout.write('\n');
        cleanup();
        resolve();
      } else if (i < text.length) {
        process.stdout.write(text[i]);
        i++;
      } else {
        clearInterval(interval);
        process.stdout.write('\n');
        cleanup();
        resolve();
      }
    }, delay);
  });
}

function validateCommand(input, expected, fuzzy = false) {
  const normalized = input.trim().toLowerCase();
  const expectedNorm = expected.toLowerCase();
  
  if (fuzzy) {
    return normalized.includes(expectedNorm) || expectedNorm.includes(normalized);
  }
  
  return normalized === expectedNorm;
}

function showHint(hint) {
  console.log(chalk.yellow('\n💡 Hint: ') + chalk.dim(hint));
}

module.exports = {
  clearScreen,
  sleep,
  printWithTypingEffect,
  validateCommand,
  showHint
};