bun

Ref: Native First-Class MDX Support Summary Adds native MDX support to Bun — files can be imported, bundled, transpiled, and served directly, just like files. — compile MDX source into a JSX module string. Supports frontmatter extraction, top-level / statements, inline , and custom JSX components. Accepts strings, TypedArrays, and ArrayBuffers. Options extend with (default: ). Loader integration — is a first-class loader (). MDX files can be -ed from // files, used with , and processed by the bundler. The MDX compiler runs at parse time, producing JSX that feeds into the existing JS parser pipeline. — serves MDX files via a dev server (same as ). Pre-compiles MDX to TSX, generates an HTML shell with a React mount point, and serves it with in development mode. Supports multi-file routing (), glob deduplication, , , and flags. File watching for HMR — watches original source files and re-compiles to the temp directory on change, so the dev server's HMR picks up edits automatically without needing . Implementation details New Zig MDX compiler () with JSX renderer () — extracts frontmatter, top-level statements, and inline expressions, then renders markdown to JSX via the existing markdown parser exposes to JS using APIs Loader enum extended with , integrated into ModuleLoader, ParseTask, LinkerContext, DevServer watch store, and the native bundler plugin API Internal entry point () handles serve mode with -based live reload routes entry points through the HTML loader path Test plan [x] — basic compilation, frontmatter, expressions, TypedArray input, , option aliases (/), invalid argument errors, malformed MDX errors, fixture documents [x] MDX loader — from entry point, import/export-heavy MDX, malformed MDX compile failure reporting [x] with [x] Dev server mode — single file serve, multi-file route mapping, route matrix, glob deduplication, binding