fix: guard missing inline input types

src/components/InlineWikilinkInput.tsx

@@ -31,6 +31,7 @@ import { handleInlineWikilinkKeyDown } from './inlineWikilinkKeydown'
 import { useInlineWikilinkSelection } from './useInlineWikilinkSelection'
 import { useInlineWikilinkSuggestionsState } from './useInlineWikilinkSuggestionsState'
 import { normalizeInlineWikilinkValue } from './inlineWikilinkTokens'
+import { isInsertBeforeInput } from './inlineWikilinkBeforeInput'
 
 interface InlineWikilinkInputProps {
   entries: VaultEntry[]
@@ -208,7 +209,7 @@ export function InlineWikilinkInput({
     if (disabled) return
 
     const nativeEvent = event.nativeEvent as InputEvent
-    if (!nativeEvent.inputType.startsWith('insert')) return
+    if (!isInsertBeforeInput(nativeEvent)) return
 
     const dataTransfer = nativeEvent.dataTransfer
     if (!dataTransfer || !hasUnsupportedClipboardPayload(dataTransfer)) return

src/components/WikilinkChatInput.test.tsx

@@ -8,7 +8,10 @@ import {
   waitFor,
 } from '@testing-library/react'
 import { WikilinkChatInput } from './WikilinkChatInput'
-import { UNSUPPORTED_INLINE_PASTE_MESSAGE } from './InlineWikilinkInput'
+import {
+  UNSUPPORTED_INLINE_PASTE_MESSAGE,
+} from './InlineWikilinkInput'
+import { isInsertBeforeInput } from './inlineWikilinkBeforeInput'
 import type { VaultEntry } from '../types'
 
 const makeEntry = (overrides: Partial<VaultEntry> = {}): VaultEntry => ({
@@ -271,6 +274,27 @@ describe('WikilinkChatInput', () => {
     expect(editor.textContent).toContain('still works')
   })
 
+  it('treats missing inputType as a non-insert beforeinput event', () => {
+    expect(() => isInsertBeforeInput({} as InputEvent)).not.toThrow()
+    expect(isInsertBeforeInput({} as InputEvent)).toBe(false)
+    expect(isInsertBeforeInput({ inputType: 'insertFromPaste' } as InputEvent)).toBe(true)
+  })
+
+  it('ignores beforeinput events without inputType instead of crashing', () => {
+    render(<Controlled />)
+
+    const editor = screen.getByTestId('agent-input')
+    const beforeInputEvent = new Event('beforeinput', {
+      bubbles: true,
+      cancelable: true,
+    })
+
+    expect(() => fireEvent(editor, beforeInputEvent)).not.toThrow()
+
+    updateEditorText('still works')
+    expect(editor.textContent).toContain('still works')
+  })
+
   it('recovers if unsupported media lands in the editor DOM', async () => {
     const onUnsupportedPaste = vi.fn()
     render(<Controlled onUnsupportedPaste={onUnsupportedPaste} />)

src/components/inlineWikilinkBeforeInput.ts

@@ -0,0 +1,4 @@
+export function isInsertBeforeInput(nativeEvent: Pick<InputEvent, 'inputType'>) {
+  return typeof nativeEvent.inputType === 'string'
+    && nativeEvent.inputType.startsWith('insert')
+}