tests/stress/test-widget-batch.js

/**
 * Batch widget render verification — mimics a real PDF/DOCX export's
 * _renderWidgets() call to /api/render_charts with several widgets.
 * Confirms the shared singleton browser handles concurrent pages correctly.
 */
const http = require('http');

const BASE = process.env.BASE_URL || 'http://localhost:17861';

function chartWidget(title, type, labels) {
  return {
    type: 'chart',
    title,
    html: `<div style="width:650px;height:300px;"><canvas id="c"></canvas></div>
<script src="https://cdn.jsdelivr.net/npm/chart.js@4.4.0/dist/chart.umd.min.js"></script>
<script>new Chart(document.getElementById("c"),{type:"${type}",data:{labels:${JSON.stringify(labels)},datasets:[{data:[3,5,2,4]}]},options:{animation:false}});</script>`
  };
}

function mermaidWidget(title, def) {
  return {
    type: 'mermaid',
    title,
    html: `<div class="mermaid">${def}</div>
<script type="module">
import mermaid from 'https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.esm.min.mjs';
mermaid.initialize({ startOnLoad: true, theme: 'default' });
</script>`
  };
}

const widgets = [
  chartWidget('bar', 'bar', ['A', 'B', 'C']),
  chartWidget('line', 'line', ['1', '2', '3']),
  chartWidget('pie', 'pie', ['X', 'Y', 'Z']),
  mermaidWidget('flow', 'graph TD\n  A[Start] --> B{Check}\n  B -->|Yes| C[Go]\n  B -->|No| D[Stop]'),
  chartWidget('doughnut', 'doughnut', ['P', 'Q']),
];

const body = JSON.stringify({ widgets, theme: 'light' });
const started = Date.now();

const req = http.request({
  hostname: 'localhost',
  port: 17861,
  path: '/api/render_charts',
  method: 'POST',
  headers: { 'Content-Type': 'application/json', 'Content-Length': Buffer.byteLength(body) },
  timeout: 180000,
}, (res) => {
  const chunks = [];
  res.on('data', (c) => chunks.push(c));
  res.on('end', () => {
    const elapsed = ((Date.now() - started) / 1000).toFixed(2);
    const data = JSON.parse(Buffer.concat(chunks).toString());
    const results = data.results || [];
    const ok = results.filter((r) => r.success).length;
    console.log(`HTTP ${res.statusCode} in ${elapsed}s: ${ok}/${results.length} widgets OK`);
    for (const r of results) {
      console.log(`  [${r.index}] ${r.type}/${r.title}: ${r.success ? 'OK len=' + r.dataUrl.length : 'FAIL ' + (r.error || '')}`);
    }
  });
});
req.on('error', (e) => { console.error('ERR', e.message); process.exit(1); });
req.write(body);
req.end();