boocode/apps/server/src/services/__tests__/html-to-md.test.ts

import { describe, expect, it } from 'vitest';
import { htmlToMarkdown } from '../web/html-to-md.js';

describe('htmlToMarkdown', () => {
  it('converts h1 heading', () => {
    expect(htmlToMarkdown('<h1>Title</h1>')).toBe('# Title');
  });

  it('converts h1 through h6', () => {
    const html = '<h1>One</h1><h2>Two</h2><h3>Three</h3><h4>Four</h4><h5>Five</h5><h6>Six</h6>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('# One');
    expect(md).toContain('## Two');
    expect(md).toContain('### Three');
    expect(md).toContain('#### Four');
    expect(md).toContain('##### Five');
    expect(md).toContain('###### Six');
  });

  it('converts anchor with href', () => {
    expect(htmlToMarkdown('<a href="https://example.com">click here</a>'))
      .toBe('[click here](https://example.com)');
  });

  it('converts anchor without href to plain text', () => {
    expect(htmlToMarkdown('<a>just text</a>')).toBe('just text');
  });

  it('converts bold and italic', () => {
    expect(htmlToMarkdown('<strong>bold</strong>')).toBe('**bold**');
    expect(htmlToMarkdown('<b>bold</b>')).toBe('**bold**');
    expect(htmlToMarkdown('<em>italic</em>')).toBe('*italic*');
    expect(htmlToMarkdown('<i>italic</i>')).toBe('*italic*');
  });

  it('handles combined bold+italic', () => {
    const md = htmlToMarkdown('<strong><em>bold italic</em></strong>');
    expect(md).toBe('***bold italic***');
  });

  it('converts unordered list', () => {
    const html = '<ul><li>one</li><li>two</li><li>three</li></ul>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('* one');
    expect(md).toContain('* two');
    expect(md).toContain('* three');
  });

  it('converts ordered list', () => {
    const html = '<ol><li>first</li><li>second</li></ol>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('1. first');
    expect(md).toContain('2. second');
  });

  it('handles nested lists', () => {
    const html = '<ul><li>outer<ul><li>inner</li></ul></li></ul>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('* outer');
    expect(md).toContain('  * inner');
  });

  it('converts 3-column GFM table with header', () => {
    const html = `
      <table>
        <thead><tr><th>Name</th><th>Age</th><th>City</th></tr></thead>
        <tbody>
          <tr><td>Alice</td><td>30</td><td>NYC</td></tr>
          <tr><td>Bob</td><td>25</td><td>LA</td></tr>
        </tbody>
      </table>`;
    const md = htmlToMarkdown(html);
    expect(md).toContain('| Name | Age | City |');
    expect(md).toContain('| --- | --- | --- |');
    expect(md).toContain('| Alice | 30 | NYC |');
    expect(md).toContain('| Bob | 25 | LA |');
  });

  it('escapes pipe characters in table cells', () => {
    const html = '<table><tr><th>A</th></tr><tr><td>x | y</td></tr></table>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('x \\| y');
  });

  it('converts blockquote', () => {
    const html = '<blockquote><p>quoted text</p></blockquote>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('> quoted text');
  });

  it('converts multi-line blockquote', () => {
    const html = '<blockquote><p>line one</p><p>line two</p></blockquote>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('> line one');
    expect(md).toContain('> line two');
  });

  it('converts fenced code block', () => {
    const html = '<pre><code>const x = 1;</code></pre>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('```\nconst x = 1;\n```');
  });

  it('preserves language hint from code class', () => {
    const html = '<pre><code class="language-py">print("hello")</code></pre>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('```py\nprint("hello")\n```');
  });

  it('converts inline code', () => {
    expect(htmlToMarkdown('use <code>npm install</code> to install'))
      .toContain('`npm install`');
  });

  it('decodes HTML entities', () => {
    expect(htmlToMarkdown('&amp; &lt; &gt; &quot;')).toBe('& < > "');
  });

  it('decodes numeric character references', () => {
    expect(htmlToMarkdown('&#39;')).toBe("'");
  });

  it('decodes &nbsp; as space', () => {
    const md = htmlToMarkdown('hello&nbsp;world');
    expect(md).toMatch(/hello\s+world/);
  });

  it('skips script content', () => {
    const html = '<p>before</p><script>alert("xss")</script><p>after</p>';
    const md = htmlToMarkdown(html);
    expect(md).not.toContain('alert');
    expect(md).toContain('before');
    expect(md).toContain('after');
  });

  it('skips style content', () => {
    const html = '<p>text</p><style>body { color: red }</style>';
    const md = htmlToMarkdown(html);
    expect(md).not.toContain('color');
    expect(md).toContain('text');
  });

  it('does not throw on malformed HTML', () => {
    expect(() => htmlToMarkdown('<p>unclosed <b>bold <i>italic')).not.toThrow();
    const md = htmlToMarkdown('<p>unclosed <b>bold <i>italic');
    expect(md).toContain('bold');
    expect(md).toContain('italic');
  });

  it('returns empty string for empty input', () => {
    expect(htmlToMarkdown('')).toBe('');
  });

  it('returns empty string for whitespace-only input', () => {
    expect(htmlToMarkdown('   \n\n  ')).toBe('');
  });

  it('converts hr to horizontal rule', () => {
    const md = htmlToMarkdown('<p>above</p><hr><p>below</p>');
    expect(md).toContain('---');
  });

  it('converts br to newline', () => {
    const md = htmlToMarkdown('line one<br>line two');
    expect(md).toContain('line one\nline two');
  });

  it('handles ol with start attribute', () => {
    const html = '<ol start="5"><li>five</li><li>six</li></ol>';
    const md = htmlToMarkdown(html);
    expect(md).toContain('5. five');
    expect(md).toContain('6. six');
  });

  it('collapses excessive blank lines', () => {
    const html = '<p>one</p><p></p><p></p><p></p><p>two</p>';
    const md = htmlToMarkdown(html);
    const blankRuns = md.match(/\n{3,}/g);
    expect(blankRuns).toBeNull();
  });

  // Golden test: small Hacker News-style snippet
  it('golden: HN-style snippet produces structured markdown', () => {
    const html = `
      <html>
      <head><title>Test Page</title></head>
      <body>
        <h1>Welcome</h1>
        <p>This is a <strong>test</strong> page with <a href="https://example.com">a link</a>.</p>
        <h2>Features</h2>
        <ul>
          <li>Fast</li>
          <li>Reliable</li>
          <li>Secure</li>
        </ul>
        <h2>Data</h2>
        <table>
          <thead><tr><th>Metric</th><th>Value</th></tr></thead>
          <tbody>
            <tr><td>Uptime</td><td>99.9%</td></tr>
            <tr><td>Latency</td><td>42ms</td></tr>
          </tbody>
        </table>
        <blockquote><p>This tool is amazing.</p></blockquote>
        <pre><code class="language-js">console.log("hello");</code></pre>
        <script>evil();</script>
      </body>
      </html>`;
    const md = htmlToMarkdown(html);
    expect(md).toContain('# Welcome');
    expect(md).toContain('**test**');
    expect(md).toContain('[a link](https://example.com)');
    expect(md).toContain('## Features');
    expect(md).toContain('* Fast');
    expect(md).toContain('| Metric | Value |');
    expect(md).toContain('| --- | --- |');
    expect(md).toContain('| Uptime | 99.9% |');
    expect(md).toContain('> This tool is amazing.');
    expect(md).toContain('```js\nconsole.log("hello");\n```');
    expect(md).not.toContain('evil');
    expect(md).not.toContain('<title>');
  });
});