Skip to content

[Bug]: Firefox never reports domcontentloaded for a document produced by an XSL transform #42417

Description

@nikitachapovskii-dev

Version

1.62.1

Steps to reproduce

Serve an XML document that references an XSL stylesheet, then navigate to it with waitUntil: 'domcontentloaded'.

import http from 'node:http';
import { chromium, firefox } from 'playwright';

const xsl = `<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/"><html><body><h1>transformed</h1></body></html></xsl:template>
</xsl:stylesheet>`;

const xml = `<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="/style.xsl"?>
<root><item>hello</item></root>`;

const server = http.createServer((req, res) => {
    const [type, body] = req.url.startsWith('/style.xsl') ? ['text/xsl', xsl] : ['application/xml', xml];
    res.writeHead(200, { 'content-type': type });
    res.end(body);
});
await new Promise((resolve) => server.listen(0, resolve));
const url = `http://127.0.0.1:${server.address().port}/doc.xml`;

for (const [name, browserType] of Object.entries({ firefox, chromium })) {
    const browser = await browserType.launch();
    const page = await browser.newPage();
    console.log(`\n${name} ${browser.version()}`);

    for (const waitUntil of ['domcontentloaded', 'load']) {
        const started = Date.now();
        try {
            await page.goto(url, { waitUntil, timeout: 5000 });
            console.log(`  goto '${waitUntil}' -> resolved in ${Date.now() - started}ms`);
        } catch (error) {
            console.log(`  goto '${waitUntil}' -> ${error.message.split('\n')[0]}`);
        }
    }

    console.log(`  document.readyState: ${await page.evaluate(() => document.readyState)}`);
    try {
        await page.waitForLoadState('domcontentloaded', { timeout: 5000 });
        console.log('  waitForLoadState(domcontentloaded) on the loaded page -> resolved');
    } catch (error) {
        console.log(`  waitForLoadState(domcontentloaded) on the loaded page -> ${error.message.split('\n')[0]}`);
    }

    await browser.close();
}
server.close();

Expected behavior

goto with waitUntil: 'domcontentloaded' resolves, as it does in Chromium and as waitUntil: 'load' does in Firefox. load cannot fire before DOMContentLoaded, so once the document is loaded, waiting for the earlier event should never block.

Actual behavior

In Firefox the event is never reported for the transform output, so both goto and waitForLoadState hit their timeout while the document is fully loaded (readyState: 'complete', transformed DOM in place). Retrying and using a fresh browser context change nothing. Chromium is fine.

Any XSL-styled XML page reproduces it, not just the local server above, e.g. https://yoast.com/sitemap_index.xml.

Additional context

No response

Environment

System:
    OS: macOS 26.2
    CPU: (14) arm64 Apple M4 Pro
    Memory: 237.63 MB / 24.00 GB
  Binaries:
    Node: 24.15.0 - /Users/.../.nvm/versions/node/v24.15.0/bin/node
    npm: 11.12.1 - /Users/.../.nvm/versions/node/v24.15.0/bin/npm
    pnpm: 11.15.1 - /opt/homebrew/bin/pnpm
  IDEs:
    Cursor: 3.15.6 - /usr/local/bin/cursor
    Claude Code: 2.1.169 - /Users/.../.local/bin/claude
  Languages:
    Bash: 3.2.57 - /bin/bash
  npmPackages:
    @playwright/browser-chromium: 1.62.1 => 1.62.1 
    @playwright/browser-firefox: 1.62.1 => 1.62.1 
    playwright: 1.62.1 => 1.62.1

Metadata

Metadata

Labels

Type

No type

Projects

No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions