feat: useDoc throws when not inside a provider

src/feature/doc/component.tsx

@@ -3,23 +3,24 @@ import * as Y from 'yjs'
 
 import { useDoc } from './hook'
 
-export const DocumentContext = React.createContext<Y.Doc>(new Y.Doc())
+export const DocumentContext = React.createContext<Y.Doc | null>(null)
 
 interface DocumentProviderProps {
   children: React.ReactNode
+  doc?: Y.Doc
   folderName?: string
   documentName?: string
 }
 
 export const DocumentProvider = ({
   children,
+  doc = new Y.Doc(),
   folderName,
   documentName
 }: DocumentProviderProps): JSX.Element => {
   let superDoc: Y.Doc | null = null
   try { superDoc = useDoc() } catch { }
 
-  const doc: Y.Doc = new Y.Doc()
   if (superDoc !== null) {
     superDoc.getMap(folderName ?? '').set(documentName ?? doc.guid, doc)
   }

src/feature/doc/hook.ts

@@ -3,4 +3,14 @@ import * as Y from 'yjs'
 
 import { DocumentContext } from './component'
 
-export const useDoc = (): Y.Doc => React.useContext(DocumentContext)
+export const useDoc = (): Y.Doc => {
+  const value = React.useContext(DocumentContext)
+
+  if (value !== null) {
+    return value
+  } else {
+    throw new Error(
+      'Could not retrieve a document. Please wrap in a DocumentProvider.'
+    )
+  }
+}

src/feature/doc/index.spec.tsx

@@ -56,4 +56,12 @@ describe('useDoc', () => {
     expect(result.current.getSubdocs().size).toBe(1)
     expect(Array.from(result.current.getSubdocs().values()).length).toBe(1)
   })
+
+  it('Throws an error when not inside a DocumentProvider.', () => {
+    const { result } = renderHook(() => useDoc())
+
+    expect(result.error).toEqual(new Error(
+      'Could not retrieve a document. Please wrap in a DocumentProvider.'
+    ))
+  })
 })