Astro 5.5 brings type-safe sessions and better support for diagramming tools in Markdown

Astro has rolled out version 5.5, bringing a host of new features and improvements to its web framework. Among the notable updates is the introduction of the excludeLangs option in the Markdown configuration, allowing users to bypass syntax highlighting for specific language code blocks. This enhancement facilitates the use of chart and diagram tools like Mermaid and D2 without affecting other syntax-highlighted blocks.

Additionally, Astro 5.5 enhances TypeScript support by providing proper typing for session data, reducing the reliance on any and improving error detection during development. The update also introduces the experimental.headingIdCompat flag, enabling consistent heading ID generation with other Markdown processors such as those used by GitHub and npm.

Another key feature is the preserveScriptOrder flag, which ensures that and tags are rendered in the order they are defined, addressing the previous issue of reversed order in the generated HTML output. The release also includes various minor enhancements and bug fixes, improving the usability and stability of the web framework.