react-router-dom@6.4.0-pre.15

Patch Changes

• fix: remove internal router singleton (#9227)

  This change removes the internal module-level routerSingleton we create and maintain inside our data routers since it was causing a number of headaches for non-simple use cases:

  • Unit tests are a pain because you need to find a way to reset the singleton in-between tests
    • Use use a _resetModuleScope singleton for our tests
    • ...but this isn't exposed to users who may want to do their own tests around our router
  • The JSX children <Route> objects cause non-intuitive behavior based on idiomatic react expectations
    • Conditional runtime <Route>'s won't get picked up
    • Adding new <Route>'s during local dev won't get picked up during HMR
    • Using external state in your elements doesn't work as one might expect (see #9225)

  Instead, we are going to lift the singleton out into user-land, so that they create the router singleton and manage it outside the react tree - which is what react 18 is encouraging with useSyncExternalStore anyways! This also means that since users create the router - there's no longer any difference in the rendering aspect for memory/browser/hash routers (which only impacts router/history creation) - so we can get rid of those and trim to a simple RouterProvider

  // Before
  function App() {
    <DataBrowserRouter>
      <Route path="/" element={<Layout />}>
        <Route index element={<Home />}>
      </Route>
    <DataBrowserRouter>
  }
  
  // After
  let router = createBrowserRouter([{
    path: "/",
    element: <Layout />,
    children: [{
      index: true,
      element: <Home />,
    }]
  }]);
  
  function App() {
    return <RouterProvider router={router} />
  }

  If folks still prefer the JSX notation, they can leverage createRoutesFromElements (aliased from createRoutesFromChildren since they are not "children" in this usage):

  let routes = createRoutesFromElements(
    <Route path="/" element={<Layout />}>
      <Route index element={<Home />}>
    </Route>
  );
  let router = createBrowserRouter(routes);
  
  function App() {
    return <RouterProvider router={router} />
  }

  And now they can also hook into HMR correctly for router disposal:

  if (import.meta.hot) {
    import.meta.hot.dispose(() => router.dispose());
  }
  

  And finally since <RouterProvider> accepts a router, it makes unit testing easer since you can create a fresh router with each test.

  Removed APIs

  • <DataMemoryRouter>
  • <DataBrowserRouter>
  • <DataHashRouter>
  • <DataRouterProvider>
  • <DataRouter>

  Modified APIs

  • createMemoryRouter/createBrowserRouter/createHashRouter used to live in @remix-run/router to prevent devs from needing to create their own history. These are now moved to react-router/react-router-dom and handle the RouteObject -> AgnosticRouteObject conversion.

  Added APIs

  • <RouterProvider>
  • createRoutesFromElements (alias of createRoutesFromChildren)

• Updated dependencies

  • react-router@6.4.0-pre.15