MDX Acorn Parsing Error

Error: [next-mdx-remote] error compiling MDX: Could not parse expression with acorn More information: https://mdxjs.com/docs/troubleshooting-mdx at resolveErrorDev (http://localhost:3001/_next/static/chunks/node_modules_next_dist_compiled_2ce9398a._.js:17582:48) at processFullStringRow (http://localhost:3001/_next/static/chunks/node_modules_next_dist_compiled_2ce9398a._.js:17798:23) at processFullBinaryRow (http://localhost:3001/_next/static/chunks/node_modules_next_dist_compiled_2ce9398a._.js:17786:9) at progress (http://localhost:3001/_next/static/chunks/node_modules_next_dist_compiled_2ce9398a._.js:17932:102) at InnerLayoutRouter (http://localhost:3001/_next/static/chunks/node_modules_next_dist_1a6ee436._.js:356:55) at OuterLayoutRouter (http://localhost:3001/_next/static/chunks/node_modules_next_dist_1a6ee436._.js:504:73)

`next-mdx-remote` pipes your `.mdx` through **@mdx-js/mdx**, which in turn asks the Acorn JavaScript parser to interpret everything that appears between a pair of braces (`{ … }`) as a *single, valid JavaScript expression*. If the text inside those braces isn’t legal JavaScript, Acorn throws and you see ``` [next-mdx-remote] error compiling MDX: Could not parse expression with acorn ``` Exactly the same rule is documented in the MDX “Troubleshooting” guide — see the *Problems writing MDX → Could not parse expression with acorn* sectionciteturn5view0. --- ## Why it’s blowing up in your file The offending line in the stack-trace contains a link with an “attribute list” (`{:target="_blank" …}`) syntax: ``` [Stackoverflow The Key](https://stackoverflow.blog/...){:target="_blank" rel="noopener"} ``` That `{ … }` block is *not* JavaScript, so MDX dutifully passes it to Acorn and the compile fails. You’re likely seeing the same class of error that others hit when they paste Markdown-it/Remark Attr-style braces into MDX files (see the discussion in issue #376)citeturn2view0. --- ## Fixes & work-arounds | Option | When to use | Example | |--------|-------------|---------| | **Escape the brace** | You just want literal text | `` \{:target="_blank"\} `` | | **Convert to plain JSX/HTML** | You want the attributes in rendered HTML and are happy to write JSX yourself | ```mdx <a href="https://stackoverflow.blog/..." target="_blank" rel="noopener">Stack Overflow – The Key</a> ``` | | **Enable a remark plugin that understands attribute lists** | You need author-friendly `{…}` attributes in Markdown | ```ts import remarkDirective from 'remark-directive'; import remarkAttr from '@recma/remark-attr'; <MDXRemote source={src} options={{ mdxOptions:{ remarkPlugins:[remarkDirective, remarkAttr] } }} /> ``` | | **Validate ahead of time** | Content comes from users; you want graceful errors | Compile the string with `import {compile} from '@mdx-js/mdx'` in a `try / catch` before saving it to the DB and reject bad MDX. | > **Heads-up on RSC** > In the **`next-mdx-remote/rsc`** API you can still pass `options={{mdxOptions:{…}}}` (despite the lack of `serialize`). That lets you add `remark-gfm`, syntax-highlighters, or the attribute-syntax plugin as shown above. --- ### Quick checklist for other Acorn parse errors 1. **Unmatched braces** Make sure every `{` has a matching `}` with no blank lines between them. 2. **JS statements instead of expressions** `if`, `for`, `const x = …` etc. are *statements*; wrap them in an IIFE or move them to a separate file and `import` them. 3. **Multiple expressions inside one brace pair** Only one expression is allowed. Split them up or use commas/arrays/objects to combine values. 4. **Wanted a brace literally?** Escape it with `\{` or put it in a code-fence. Following those rules should stop the Acorn crashes and let your MDX compile cleanly. If the problem persists after trying the fixes above, share the exact snippet that’s still failing and I can pinpoint the next culprit.