generate-chart.js

#!/usr/bin/env node

/**
 * Wunderbar Chart Generator
 *
 * Generates horizontal bar chart visualization from benchmark-results.json
 * using wunderbar (https://github.com/gribnoysup/wunderbar).
 *
 * This script is automatically called by benchmark.sh to create charts
 * with precise partial block characters (▏▎▍▌▋▊▉█).
 *
 * Usage:
 *   node generate-chart.js
 *
 * Requirements:
 *   - benchmark-results.json must exist (generated by hyperfine)
 *   - @gribnoysup/wunderbar must be installed
 */

const fs = require('fs');
const wunderbar = require('@gribnoysup/wunderbar');

// Read benchmark results
const RESULTS_FILE = 'benchmark-results.json';

if (!fs.existsSync(RESULTS_FILE)) {
  console.error(`Error: ${RESULTS_FILE} not found. Run ./benchmark.sh first.`);
  process.exit(1);
}

const benchmarkData = JSON.parse(fs.readFileSync(RESULTS_FILE, 'utf8'));

// Sort by mean time (fastest first) and extract data
const results = benchmarkData.results
  .sort((a, b) => a.mean - b.mean)
  .map(result => ({
    name: result.command,
    mean: result.mean,
    meanFormatted: (result.mean).toFixed(2),
  }));

// Get fastest time for relative calculation
const fastestTime = results[0].mean;

// Prepare data for wunderbar
const data = results.map(r => ({
  value: r.mean,
  label: r.name,
}));

// Calculate max value (round up to next second for nice scale)
const maxValue = Math.ceil(results[results.length - 1].mean);

const { chart, scale } = wunderbar(data, {
  min: 0,
  max: maxValue,
  length: 50,
  format: '0.00',
});

console.log('🚀 Generation Time Comparison (lower is better)\n');

// Combine labels with bars manually
const chartLines = chart.split('\n').filter(line => line.trim());

chartLines.forEach((line, idx) => {
  if (idx < results.length) {
    const result = results[idx];
    const relative = (result.mean / fastestTime).toFixed(1);
    const relativeText = idx === 0 ? '1.0x' : `${relative}x`;
    const mean = `${result.meanFormatted}s`

    // Format label with padding
    const label = `${result.name.padEnd(15)} ${mean.padEnd(6)} `;
    console.log(`${label} ${line} ${relativeText}`);
  }
});

console.log(`                        ${scale}`);