Enable windowHistorySupport by default

docs/02-app/01-building-your-application/01-routing/03-linking-and-navigating.mdx

@@ -188,7 +188,7 @@ For a full list of `useRouter` methods, see the [API reference](/docs/app/api-re
 
 Next.js allows you to use the native [`window.history.pushState`](https://developer.mozilla.org/en-US/docs/Web/API/History/pushState) and [`window.history.replaceState`](https://developer.mozilla.org/en-US/docs/Web/API/History/replaceState) methods to update the browser's history stack without reloading the page.
 
-This behavior is enabled with the Next.js [`windowHistorySupport`](/docs/app/api-reference/next-config-js/windowHistorySupport) config option. When the flag is set to `true`, `pushState` and `replaceState` calls integrate into the Next.js Router, allowing you to sync with [`usePathname`](/docs/app/api-reference/functions/use-pathname) and [`useSearchParams`](/docs/app/api-reference/functions/use-search-params).
+`pushState` and `replaceState` calls integrate into the Next.js Router, allowing you to sync with [`usePathname`](/docs/app/api-reference/functions/use-pathname) and [`useSearchParams`](/docs/app/api-reference/functions/use-search-params).
 
 ### `window.history.pushState`
 

packages/next/src/build/webpack/plugins/define-env-plugin.ts

@@ -95,9 +95,6 @@ export function getDefineEnv({
       isEdgeServer ? 'edge' : isNodeServer ? 'nodejs' : ''
     ),
     'process.env.NEXT_MINIMAL': JSON.stringify(''),
-    'process.env.__NEXT_WINDOW_HISTORY_SUPPORT': JSON.stringify(
-      config.experimental.windowHistorySupport
-    ),
     'process.env.__NEXT_PPR': JSON.stringify(config.experimental.ppr === true),
     'process.env.__NEXT_ACTIONS_DEPLOYMENT_ID': JSON.stringify(
       config.experimental.useDeploymentIdServerActions

packages/next/src/client/components/app-router.tsx

@@ -122,10 +122,7 @@ function HistoryUpdater({
   useInsertionEffect(() => {
     const { tree, pushRef, canonicalUrl } = appRouterState
     const historyState = {
-      ...(process.env.__NEXT_WINDOW_HISTORY_SUPPORT &&
-      pushRef.preserveCustomHistoryState
-        ? window.history.state
-        : {}),
+      ...(pushRef.preserveCustomHistoryState ? window.history.state : {}),
       // Identifier is shortened intentionally.
       // __NA is used to identify if the history entry can be handled by the app-router.
       // __N is used to identify if the history entry can be handled by the old router.
@@ -467,65 +464,64 @@ function Router({
     const originalReplaceState = window.history.replaceState.bind(
       window.history
     )
-    if (process.env.__NEXT_WINDOW_HISTORY_SUPPORT) {
-      // Ensure the canonical URL in the Next.js Router is updated when the URL is changed so that `usePathname` and `useSearchParams` hold the pushed values.
-      const applyUrlFromHistoryPushReplace = (
-        url: string | URL | null | undefined
-      ) => {
-        const href = window.location.href
-        startTransition(() => {
-          dispatch({
-            type: ACTION_RESTORE,
-            url: new URL(url ?? href, href),
-            tree: window.history.state.__PRIVATE_NEXTJS_INTERNALS_TREE,
-          })
-        })
-      }
-
-      /**
-       * Patch pushState to ensure external changes to the history are reflected in the Next.js Router.
-       * Ensures Next.js internal history state is copied to the new history entry.
-       * Ensures usePathname and useSearchParams hold the newly provided url.
-       */
-      window.history.pushState = function pushState(
-        data: any,
-        _unused: string,
-        url?: string | URL | null
-      ): void {
-        // Avoid a loop when Next.js internals trigger pushState/replaceState
-        if (data?.__NA || data?._N) {
-          return originalPushState(data, _unused, url)
-        }
-        data = copyNextJsInternalHistoryState(data)
 
-        if (url) {
-          applyUrlFromHistoryPushReplace(url)
-        }
+    // Ensure the canonical URL in the Next.js Router is updated when the URL is changed so that `usePathname` and `useSearchParams` hold the pushed values.
+    const applyUrlFromHistoryPushReplace = (
+      url: string | URL | null | undefined
+    ) => {
+      const href = window.location.href
+      startTransition(() => {
+        dispatch({
+          type: ACTION_RESTORE,
+          url: new URL(url ?? href, href),
+          tree: window.history.state.__PRIVATE_NEXTJS_INTERNALS_TREE,
+        })
+      })
+    }
 
+    /**
+     * Patch pushState to ensure external changes to the history are reflected in the Next.js Router.
+     * Ensures Next.js internal history state is copied to the new history entry.
+     * Ensures usePathname and useSearchParams hold the newly provided url.
+     */
+    window.history.pushState = function pushState(
+      data: any,
+      _unused: string,
+      url?: string | URL | null
+    ): void {
+      // Avoid a loop when Next.js internals trigger pushState/replaceState
+      if (data?.__NA || data?._N) {
         return originalPushState(data, _unused, url)
       }
+      data = copyNextJsInternalHistoryState(data)
 
-      /**
-       * Patch replaceState to ensure external changes to the history are reflected in the Next.js Router.
-       * Ensures Next.js internal history state is copied to the new history entry.
-       * Ensures usePathname and useSearchParams hold the newly provided url.
-       */
-      window.history.replaceState = function replaceState(
-        data: any,
-        _unused: string,
-        url?: string | URL | null
-      ): void {
-        // Avoid a loop when Next.js internals trigger pushState/replaceState
-        if (data?.__NA || data?._N) {
-          return originalReplaceState(data, _unused, url)
-        }
-        data = copyNextJsInternalHistoryState(data)
+      if (url) {
+        applyUrlFromHistoryPushReplace(url)
+      }
 
-        if (url) {
-          applyUrlFromHistoryPushReplace(url)
-        }
+      return originalPushState(data, _unused, url)
+    }
+
+    /**
+     * Patch replaceState to ensure external changes to the history are reflected in the Next.js Router.
+     * Ensures Next.js internal history state is copied to the new history entry.
+     * Ensures usePathname and useSearchParams hold the newly provided url.
+     */
+    window.history.replaceState = function replaceState(
+      data: any,
+      _unused: string,
+      url?: string | URL | null
+    ): void {
+      // Avoid a loop when Next.js internals trigger pushState/replaceState
+      if (data?.__NA || data?._N) {
         return originalReplaceState(data, _unused, url)
       }
+      data = copyNextJsInternalHistoryState(data)
+
+      if (url) {
+        applyUrlFromHistoryPushReplace(url)
+      }
+      return originalReplaceState(data, _unused, url)
     }
 
     /**
@@ -560,10 +556,8 @@ function Router({
     // Register popstate event to call onPopstate.
     window.addEventListener('popstate', onPopState)
     return () => {
-      if (process.env.__NEXT_WINDOW_HISTORY_SUPPORT) {
-        window.history.pushState = originalPushState
-        window.history.replaceState = originalReplaceState
-      }
+      window.history.pushState = originalPushState
+      window.history.replaceState = originalReplaceState
       window.removeEventListener('popstate', onPopState)
     }
   }, [dispatch])

packages/next/src/server/config-schema.ts

@@ -226,7 +226,6 @@ export const configSchema: zod.ZodType<NextConfig> = z.lazy(() =>
     excludeDefaultMomentLocales: z.boolean().optional(),
     experimental: z
       .strictObject({
-        windowHistorySupport: z.boolean().optional(),
         appDocumentPreloading: z.boolean().optional(),
         adjustFontFallbacks: z.boolean().optional(),
         adjustFontFallbacksWithSizeAdjust: z.boolean().optional(),

packages/next/src/server/config-shared.ts

@@ -159,7 +159,6 @@ export interface NextJsWebpackConfig {
 }
 
 export interface ExperimentalConfig {
-  windowHistorySupport?: boolean
   caseSensitiveRoutes?: boolean
   useDeploymentId?: boolean
   useDeploymentIdServerActions?: boolean
@@ -780,7 +779,6 @@ export const defaultConfig: NextConfig = {
   output: !!process.env.NEXT_PRIVATE_STANDALONE ? 'standalone' : undefined,
   modularizeImports: undefined,
   experimental: {
-    windowHistorySupport: false,
     serverMinification: true,
     serverSourceMaps: false,
     caseSensitiveRoutes: false,

test/e2e/app-dir/shallow-routing/next.config.js

@@ -1,10 +1,6 @@
 /**
  * @type {import('next').NextConfig}
  */
-const nextConfig = {
-  experimental: {
-    windowHistorySupport: true,
-  },
-}
+const nextConfig = {}
 
 module.exports = nextConfig