René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"HTML parser crash: HTML_BOGUS cast failure on '\u003c' character in text content","articleBody":"## Environment\n\n- **Biome version**: 2.3.8\n- **Node.js version**: v25.2.1\n- **OS**: macOS Darwin 25.1.0 (darwin-arm64)\n\n## Description\n\nWhen running `biome check` on HTML files, Biome crashes with an internal error when it encounters a `\u003c` character followed by a number in text content (e.g., `\u003c12 months`).\n\nWhile Biome correctly identifies this as a parse error (it expects `\u003c` to start a tag), the internal handling causes a thread panic with `HTML_BOGUS` cast failure.\n\n## Error Message\n\n```\nBiome encountered an unexpected error\n\nThis is a bug in Biome, not an error in your code, and we would appreciate it if you could report it to https://github.com/biomejs/biome/issues/ along with the following information to help us fixing the issue.\n\nSource Location: /Users/runner/work/biome/biome/crates/biome_rowan/src/ast/mod.rs:206:13\nThread Name: biome::workspace_worker_0\nMessage: Tried to cast node with kind HTML_BOGUS as \"biome_html_syntax::generated::nodes::HtmlRoot\" but was unable to cast\n```\n\n## Minimal Reproduction\n\nCreate a file `test.html`:\n\n```html\n\u003c!DOCTYPE html\u003e\n\u003chtml lang=\"en\"\u003e\n\u003chead\u003e\n    \u003ctitle\u003eTest\u003c/title\u003e\n\u003c/head\u003e\n\u003cbody\u003e\n    \u003cdiv\u003eTarget \u003c12 months\u003c/div\u003e\n\u003c/body\u003e\n\u003c/html\u003e\n```\n\nRun:\n```bash\nnpx @biomejs/biome check test.html\n```\n\nThe parse error is expected (Biome interprets `\u003c12` as an invalid tag start), but the crash with `HTML_BOGUS` cast failure should not occur.\n\n## Expected Behavior\n\nBiome should report the parse error gracefully without crashing. The error message for the parse issue is fine:\n\n```\ntest.html:7:17 parse ━━━━━━━━━━━━━━━━━━━━━━━━\n\n  × Expected an attribute but instead found '\u003c'.\n\n  \u003e 7 │     \u003cdiv\u003eTarget \u003c12 months\u003c/div\u003e\n      │                 ^\n```\n\nBut after reporting this, it should continue processing without the internal `HTML_BOGUS` cast failure.\n\n## Additional Context\n\n- The error occurred multiple times (4 times in my case) when running on a directory with multiple HTML files containing similar patterns\n- No `biome.json` configuration file was present (default settings)\n- The `\u003c` followed by a number pattern (like `\u003c12`) is common in content discussing metrics, comparisons, or mathematical expressions","author":{"url":"https://github.com/aledlie","@type":"Person","name":"aledlie"},"datePublished":"2025-12-04T20:01:12.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/8363/biome/issues/8363"}