chore: import upstream snapshot with attribution

test/site/markdown.test.ts

@@ -0,0 +1,96 @@
+import { describe, expect, it } from 'vitest';
+import { sanitizeMarkdown } from '../../site/src/utils/markdown';
+
+describe('sanitizeMarkdown', () => {
+  const sampleMarkdown = `---
+title: Test Document
+author: Test Author
+---
+
+# Main Title
+
+This is a paragraph with ![an image](image.jpg) and some text.
+
+<!-- This is a comment -->
+
+<div style="color: red;">Styled content</div>
+
+\`\`\`javascript
+console.log('code block');
+\`\`\`
+
+Here's some \`inline code\` and a [link](https://example.com).
+
+<img src="test.jpg" alt="HTML image" />
+
+
+Multiple newlines above.
+`;
+
+  it('should sanitize markdown with sane defaults', () => {
+    const result = sanitizeMarkdown(sampleMarkdown);
+
+    expect(result).not.toContain('---');
+    expect(result).not.toContain('title: Test Document');
+    expect(result).not.toContain('author: Test Author');
+
+    expect(result).not.toContain('![an image](image.jpg)');
+    expect(result).not.toContain('<img src="test.jpg"');
+
+    expect(result).not.toContain('<!-- This is a comment -->');
+
+    expect(result).not.toContain('<div style="color: red;">');
+    expect(result).toContain('Styled content');
+
+    expect(result).toContain('console.log');
+    expect(result).toContain('```javascript');
+    expect(result).toContain('`inline code`');
+    expect(result).toContain('[link](https://example.com)');
+
+    expect(result).not.toMatch(/\n\n\n/);
+    expect(result).toMatch(/^# Main Title/);
+  });
+
+  it('should handle empty string', () => {
+    expect(sanitizeMarkdown('')).toBe('');
+  });
+
+  it('should handle null/undefined input', () => {
+    expect(sanitizeMarkdown(null as any)).toBe('');
+    expect(sanitizeMarkdown(undefined as any)).toBe('');
+  });
+
+  it('should handle non-string input', () => {
+    expect(sanitizeMarkdown(123 as any)).toBe('');
+  });
+
+  it('should handle TOML frontmatter', () => {
+    const tomlMarkdown = `+++
+title = "Test"
++++
+
+# Content`;
+    const result = sanitizeMarkdown(tomlMarkdown);
+    expect(result).not.toContain('+++');
+    expect(result).not.toContain('title = "Test"');
+    expect(result).toContain('# Content');
+  });
+
+  it('should preserve markdown formatting', () => {
+    const formattedMarkdown = `# Heading
+
+**Bold text** and *italic text*
+
+- List item 1
+- List item 2
+
+> Blockquote`;
+
+    const result = sanitizeMarkdown(formattedMarkdown);
+    expect(result).toContain('# Heading');
+    expect(result).toContain('**Bold text**');
+    expect(result).toContain('*italic text*');
+    expect(result).toContain('- List item 1');
+    expect(result).toContain('> Blockquote');
+  });
+});