fix(solid-router): avoid HeadContent remounts on history.replaceState

packages/react-router/tests/Scripts.test.tsx

@@ -1,17 +1,59 @@
-import { describe, expect, test } from 'vitest'
-import { act, render, screen } from '@testing-library/react'
+import { afterEach, describe, expect, test } from 'vitest'
+import {
+  act,
+  cleanup,
+  fireEvent,
+  render,
+  screen,
+  waitFor,
+} from '@testing-library/react'
+import { createPortal } from 'react-dom'
 import ReactDOMServer from 'react-dom/server'
 
 import {
   HeadContent,
+  Link,
   Outlet,
   RouterProvider,
+  createBrowserHistory,
   createMemoryHistory,
   createRootRoute,
   createRoute,
   createRouter,
 } from '../src'
 import { Scripts } from '../src/Scripts'
+import type { Manifest } from '@tanstack/router-core'
+
+const createTestManifest = (routeId: string) =>
+  ({
+    routes: {
+      [routeId]: {
+        assets: [
+          {
+            tag: 'link',
+            attrs: {
+              rel: 'stylesheet',
+              href: '/main.css',
+            },
+          },
+        ],
+      },
+    },
+  }) satisfies Manifest
+
+const browserHistories: Array<ReturnType<typeof createBrowserHistory>> = []
+
+const createTestBrowserHistory = () => {
+  const history = createBrowserHistory()
+  browserHistories.push(history)
+  return history
+}
+
+afterEach(() => {
+  cleanup()
+  browserHistories.splice(0).forEach((history) => history.destroy())
+  window.history.replaceState(null, 'root', '/')
+})
 
 describe('ssr scripts', () => {
   test('it works', async () => {
@@ -327,6 +369,155 @@ describe('ssr HeadContent', () => {
       `<title>Index</title><meta name="image" content="image.jpg"/><meta property="og:description" content="Root description"/><meta name="description" content="Index"/><meta name="last-modified" content="2021-10-10"/><meta property="og:image" content="index-image.jpg"/>`,
     )
   })
+
+  test('keeps manifest stylesheet links mounted when history state changes', async () => {
+    const history = createTestBrowserHistory()
+
+    const rootRoute = createRootRoute({
+      component: () => {
+        return (
+          <>
+            {createPortal(<HeadContent />, document.head)}
+            <button
+              onClick={() => {
+                window.history.replaceState(
+                  { slideId: 'slide-2' },
+                  '',
+                  window.location.href,
+                )
+              }}
+            >
+              Replace state
+            </button>
+            <Outlet />
+          </>
+        )
+      },
+    })
+
+    const indexRoute = createRoute({
+      path: '/',
+      getParentRoute: () => rootRoute,
+      component: () => <div>Index</div>,
+    })
+
+    const router = createRouter({
+      history,
+      routeTree: rootRoute.addChildren([indexRoute]),
+    })
+
+    router.ssr = {
+      manifest: createTestManifest(rootRoute.id),
+    }
+
+    await router.load()
+
+    await act(() => render(<RouterProvider router={router} />))
+
+    const getStylesheetLink = () =>
+      Array.from(document.querySelectorAll('link[rel="stylesheet"]')).find(
+        (link) => link.getAttribute('href') === '/main.css',
+      )
+
+    await waitFor(() => {
+      expect(getStylesheetLink()).toBeInstanceOf(HTMLLinkElement)
+    })
+
+    const initialLink = getStylesheetLink()
+    expect(initialLink).toBeInstanceOf(HTMLLinkElement)
+
+    fireEvent.click(screen.getByRole('button', { name: 'Replace state' }))
+
+    await waitFor(() => {
+      expect(router.state.location.state).toMatchObject({
+        slideId: 'slide-2',
+      })
+    })
+
+    expect(getStylesheetLink()).toBe(initialLink)
+    expect(
+      Array.from(document.querySelectorAll('link[rel="stylesheet"]')).filter(
+        (link) => link.getAttribute('href') === '/main.css',
+      ),
+    ).toHaveLength(1)
+  })
+
+  test('keeps manifest stylesheet links mounted across repeated Link navigations', async () => {
+    const history = createTestBrowserHistory()
+
+    const rootRoute = createRootRoute({
+      component: () => {
+        return (
+          <>
+            {createPortal(<HeadContent />, document.head)}
+            <Outlet />
+          </>
+        )
+      },
+    })
+
+    const indexRoute = createRoute({
+      path: '/',
+      getParentRoute: () => rootRoute,
+      component: () => <Link to="/about">Go to about page</Link>,
+    })
+
+    const aboutRoute = createRoute({
+      path: '/about',
+      getParentRoute: () => rootRoute,
+      component: () => <Link to="/">Back to home</Link>,
+    })
+
+    const router = createRouter({
+      history,
+      routeTree: rootRoute.addChildren([indexRoute, aboutRoute]),
+    })
+
+    router.ssr = {
+      manifest: createTestManifest(rootRoute.id),
+    }
+
+    await router.load()
+
+    await act(() => render(<RouterProvider router={router} />))
+
+    const getStylesheetLink = () =>
+      Array.from(document.querySelectorAll('link[rel="stylesheet"]')).find(
+        (link) => link.getAttribute('href') === '/main.css',
+      )
+
+    await waitFor(() => {
+      expect(getStylesheetLink()).toBeInstanceOf(HTMLLinkElement)
+    })
+
+    const initialLink = getStylesheetLink()
+    expect(initialLink).toBeInstanceOf(HTMLLinkElement)
+
+    for (let i = 0; i < 5; i++) {
+      fireEvent.click(screen.getByRole('link', { name: 'Go to about page' }))
+
+      await waitFor(() => {
+        expect(router.state.location.pathname).toBe('/about')
+      })
+
+      await screen.findByRole('link', { name: 'Back to home' })
+
+      fireEvent.click(screen.getByRole('link', { name: 'Back to home' }))
+
+      await waitFor(() => {
+        expect(router.state.location.pathname).toBe('/')
+      })
+
+      await screen.findByRole('link', { name: 'Go to about page' })
+    }
+
+    expect(getStylesheetLink()).toBe(initialLink)
+    expect(
+      Array.from(document.querySelectorAll('link[rel="stylesheet"]')).filter(
+        (link) => link.getAttribute('href') === '/main.css',
+      ),
+    ).toHaveLength(1)
+  })
 })
 
 describe('data script rendering', () => {

packages/solid-router/src/headContentUtils.tsx

@@ -1,5 +1,5 @@
 import * as Solid from 'solid-js'
-import { escapeHtml } from '@tanstack/router-core'
+import { escapeHtml, replaceEqualDeep } from '@tanstack/router-core'
 import { useRouter } from './useRouter'
 import type { RouterManagedTag } from '@tanstack/router-core'
 
@@ -179,8 +179,8 @@ export const useTags = () => {
     })),
   )
 
-  return () =>
-    uniqBy(
+  return Solid.createMemo((prev: Array<RouterManagedTag> | undefined) => {
+    const next = uniqBy(
       [
         ...meta(),
         ...preloadLinks(),
@@ -192,6 +192,11 @@ export const useTags = () => {
         return JSON.stringify(d)
       },
     )
+    if (prev === undefined) {
+      return next
+    }
+    return replaceEqualDeep(prev, next)
+  })
 }
 
 export function uniqBy<T>(arr: Array<T>, fn: (item: T) => string) {