can't access property "type", node is undefined

[elijah629]

Bug Description

I get an error can't access property "type", node is undefined when rendering any markdown with streamdown. This error occurs regardless of streaming state.

Steps to Reproduce

1. Render any markdown
2. See error

Expected Behavior

No error is emitted

Actual Behavior

The error is emitted

Code Sample

Streamdown Version

1.6.9

React Version

19.2.0

Node.js Version

24.10.1

Browser(s)

Firefox

Operating System

Linux

Additional Context

## Error Type
Recoverable TypeError

## Error Message
can't access property "type", node is undefined

Next.js version: 16.0.5 (Turbopack)

## Call Stack

visitor
node_modules/rehype-harden/src/index.ts (218:7)
overload
node_modules/unist-util-visit/lib/index.js (311:12)
visit
node_modules/unist-util-visit-parents/lib/index.js (347:27)
visitParents
node_modules/unist-util-visit-parents/lib/index.js (305:30)
visit
node_modules/unist-util-visit/lib/index.js (302:15)
harden/<
node_modules/rehype-harden/src/index.ts (44:10)
freeze
node_modules/unified/lib/index.js (636:36)
parse
node_modules/unified/lib/index.js (664:10)
ye
node_modules/streamdown/dist/chunk-T7OEMACY.js (7:13537)
react_stack_bottom_frame
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (28016:20)
renderWithHooks
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (7982:22)
updateFunctionComponent
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (10499:19)
beginWork
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (12134:18)
runWithFiberInDEV
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (987:13)
performUnitOfWork
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (18995:22)
workLoopConcurrentByScheduler
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (18989:9)
renderRootConcurrent
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (18971:15)
performWorkOnRoot
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (17832:11)
performWorkOnRootViaSchedulerTask
node_modules/next/dist/compiled/react-dom/cjs/react-dom-client.development.js (20382:7)
performWorkUntilDeadline
node_modules/next/dist/compiled/scheduler/cjs/scheduler.development.js (45:48)
<unknown>
HTTPAccessFallbackBoundary@http://localhost:3000/_next/static/chunks/node_modules_next_dist_client_aaee43fe._.js (9889:50)
DevRootHTTPAccessFallbackBoundary
node_modules/next/src/client/components/dev-root-http-access-fallback-boundary.tsx (22:5)
Router
node_modules/next/src/client/components/app-router.tsx (501:9)
AppRouter
node_modules/next/src/client/components/app-router.tsx (577:5)
ServerRoot
node_modules/next/src/client/app-index.tsx (235:5)