fix(router): prevent script tag duplication in SSR and client-side navigation (#5095)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: jamongsalguclub

e2e/react-start/basic/src/routeTree.gen.ts

@@ -23,6 +23,7 @@ import { Route as StreamRouteImport } from './routes/stream'
 import { Route as ScriptsRouteImport } from './routes/scripts'
 import { Route as PostsRouteImport } from './routes/posts'
 import { Route as LinksRouteImport } from './routes/links'
+import { Route as InlineScriptsRouteImport } from './routes/inline-scripts'
 import { Route as DeferredRouteImport } from './routes/deferred'
 import { Route as LayoutRouteImport } from './routes/_layout'
 import { Route as SearchParamsRouteRouteImport } from './routes/search-params/route'
@@ -90,6 +91,11 @@ const LinksRoute = LinksRouteImport.update({
   path: '/links',
   getParentRoute: () => rootRouteImport,
 } as any)
+const InlineScriptsRoute = InlineScriptsRouteImport.update({
+  id: '/inline-scripts',
+  path: '/inline-scripts',
+  getParentRoute: () => rootRouteImport,
+} as any)
 const DeferredRoute = DeferredRouteImport.update({
   id: '/deferred',
   path: '/deferred',
@@ -264,6 +270,7 @@ export interface FileRoutesByFullPath {
   '/not-found': typeof NotFoundRouteRouteWithChildren
   '/search-params': typeof SearchParamsRouteRouteWithChildren
   '/deferred': typeof DeferredRoute
+  '/inline-scripts': typeof InlineScriptsRoute
   '/links': typeof LinksRoute
   '/posts': typeof PostsRouteWithChildren
   '/scripts': typeof ScriptsRoute
@@ -298,6 +305,7 @@ export interface FileRoutesByFullPath {
 export interface FileRoutesByTo {
   '/': typeof IndexRoute
   '/deferred': typeof DeferredRoute
+  '/inline-scripts': typeof InlineScriptsRoute
   '/links': typeof LinksRoute
   '/scripts': typeof ScriptsRoute
   '/stream': typeof StreamRoute
@@ -332,6 +340,7 @@ export interface FileRoutesById {
   '/search-params': typeof SearchParamsRouteRouteWithChildren
   '/_layout': typeof LayoutRouteWithChildren
   '/deferred': typeof DeferredRoute
+  '/inline-scripts': typeof InlineScriptsRoute
   '/links': typeof LinksRoute
   '/posts': typeof PostsRouteWithChildren
   '/scripts': typeof ScriptsRoute
@@ -372,6 +381,7 @@ export interface FileRouteTypes {
     | '/not-found'
     | '/search-params'
     | '/deferred'
+    | '/inline-scripts'
     | '/links'
     | '/posts'
     | '/scripts'
@@ -406,6 +416,7 @@ export interface FileRouteTypes {
   to:
     | '/'
     | '/deferred'
+    | '/inline-scripts'
     | '/links'
     | '/scripts'
     | '/stream'
@@ -439,6 +450,7 @@ export interface FileRouteTypes {
     | '/search-params'
     | '/_layout'
     | '/deferred'
+    | '/inline-scripts'
     | '/links'
     | '/posts'
     | '/scripts'
@@ -479,6 +491,7 @@ export interface RootRouteChildren {
   SearchParamsRouteRoute: typeof SearchParamsRouteRouteWithChildren
   LayoutRoute: typeof LayoutRouteWithChildren
   DeferredRoute: typeof DeferredRoute
+  InlineScriptsRoute: typeof InlineScriptsRoute
   LinksRoute: typeof LinksRoute
   PostsRoute: typeof PostsRouteWithChildren
   ScriptsRoute: typeof ScriptsRoute
@@ -552,6 +565,13 @@ declare module '@tanstack/react-router' {
       preLoaderRoute: typeof DeferredRouteImport
       parentRoute: typeof rootRouteImport
     }
+    '/inline-scripts': {
+      id: '/inline-scripts'
+      path: '/inline-scripts'
+      fullPath: '/inline-scripts'
+      preLoaderRoute: typeof InlineScriptsRouteImport
+      parentRoute: typeof rootRouteImport
+    }
     '/links': {
       id: '/links'
       path: '/links'
@@ -829,6 +849,13 @@ declare module '@tanstack/react-start/server' {
       preLoaderRoute: unknown
       parentRoute: typeof rootServerRouteImport
     }
+    '/inline-scripts': {
+      id: '/inline-scripts'
+      path: '/inline-scripts'
+      fullPath: '/inline-scripts'
+      preLoaderRoute: unknown
+      parentRoute: typeof rootServerRouteImport
+    }
     '/links': {
       id: '/links'
       path: '/links'
@@ -1148,6 +1175,23 @@ declare module './routes/deferred' {
     unknown
   >
 }
+declare module './routes/inline-scripts' {
+  const createFileRoute: CreateFileRoute<
+    '/inline-scripts',
+    FileRoutesByPath['/inline-scripts']['parentRoute'],
+    FileRoutesByPath['/inline-scripts']['id'],
+    FileRoutesByPath['/inline-scripts']['path'],
+    FileRoutesByPath['/inline-scripts']['fullPath']
+  >
+
+  const createServerFileRoute: CreateServerFileRoute<
+    ServerFileRoutesByPath['/inline-scripts']['parentRoute'],
+    ServerFileRoutesByPath['/inline-scripts']['id'],
+    ServerFileRoutesByPath['/inline-scripts']['path'],
+    ServerFileRoutesByPath['/inline-scripts']['fullPath'],
+    unknown
+  >
+}
 declare module './routes/links' {
   const createFileRoute: CreateFileRoute<
     '/links',
@@ -1858,6 +1902,7 @@ const rootRouteChildren: RootRouteChildren = {
   SearchParamsRouteRoute: SearchParamsRouteRouteWithChildren,
   LayoutRoute: LayoutRouteWithChildren,
   DeferredRoute: DeferredRoute,
+  InlineScriptsRoute: InlineScriptsRoute,
   LinksRoute: LinksRoute,
   PostsRoute: PostsRouteWithChildren,
   ScriptsRoute: ScriptsRoute,

e2e/react-start/basic/src/routes/__root.tsx

@@ -141,6 +141,14 @@ function RootDocument({ children }: { children: React.ReactNode }) {
           >
             Scripts
           </Link>{' '}
+          <Link
+            to="/inline-scripts"
+            activeProps={{
+              className: 'font-bold',
+            }}
+          >
+            Inline Scripts
+          </Link>{' '}
           <Link
             to="/deferred"
             activeProps={{

e2e/react-start/basic/src/routes/inline-scripts.tsx

@@ -0,0 +1,28 @@
+export const Route = createFileRoute({
+  head: () => ({
+    scripts: [
+      {
+        children:
+          'window.INLINE_SCRIPT_1 = true; console.log("Inline script 1 executed");',
+      },
+      {
+        children:
+          'window.INLINE_SCRIPT_2 = "test"; console.log("Inline script 2 executed");',
+        type: 'text/javascript',
+      },
+    ],
+  }),
+  component: InlineScriptsComponent,
+})
+
+function InlineScriptsComponent() {
+  return (
+    <div className="p-2">
+      <h3 data-testid="inline-scripts-test-heading">Inline Scripts Test</h3>
+      <p>
+        This route tests inline script duplication prevention. Two inline
+        scripts should be loaded.
+      </p>
+    </div>
+  )
+}

e2e/react-start/basic/tests/navigation.spec.ts

@@ -34,7 +34,7 @@ test('Navigating nested layouts', async ({ page }) => {
 
 test('client side navigating to a route with scripts', async ({ page }) => {
   await page.goto('/')
-  await page.getByRole('link', { name: 'Scripts' }).click()
+  await page.getByRole('link', { name: 'Scripts', exact: true }).click()
   await expect(page.getByTestId('scripts-test-heading')).toBeInViewport()
   expect(await page.evaluate('window.SCRIPT_1')).toBe(true)
   expect(await page.evaluate('window.SCRIPT_2')).toBe(undefined)

e2e/react-start/basic/tests/script-duplication.spec.ts

@@ -0,0 +1,143 @@
+import { expect, test } from '@playwright/test'
+
+test.describe('Script Duplication Prevention', () => {
+  test('should not create duplicate scripts on SSR route', async ({ page }) => {
+    await page.goto('/scripts')
+
+    await expect(page.getByTestId('scripts-test-heading')).toBeInViewport()
+
+    const scriptCount = await page.evaluate(() => {
+      return document.querySelectorAll('script[src="script.js"]').length
+    })
+
+    expect(scriptCount).toBe(1)
+
+    expect(await page.evaluate('window.SCRIPT_1')).toBe(true)
+  })
+
+  test('should not create duplicate scripts during client-side navigation', async ({
+    page,
+  }) => {
+    await page.goto('/')
+
+    await page.getByRole('link', { name: 'Scripts', exact: true }).click()
+    await expect(page.getByTestId('scripts-test-heading')).toBeInViewport()
+
+    const firstNavCount = await page.evaluate(() => {
+      return document.querySelectorAll('script[src="script.js"]').length
+    })
+    expect(firstNavCount).toBe(1)
+
+    await page.getByRole('link', { name: 'Home' }).click()
+    await expect(page.getByRole('link', { name: 'Posts' })).toBeVisible()
+
+    await page.getByRole('link', { name: 'Scripts', exact: true }).click()
+    await expect(page.getByTestId('scripts-test-heading')).toBeInViewport()
+
+    const secondNavCount = await page.evaluate(() => {
+      return document.querySelectorAll('script[src="script.js"]').length
+    })
+    expect(secondNavCount).toBe(1)
+
+    expect(await page.evaluate('window.SCRIPT_1')).toBe(true)
+  })
+
+  test('should not create duplicate scripts with multiple navigation cycles', async ({
+    page,
+  }) => {
+    await page.goto('/')
+
+    for (let i = 0; i < 3; i++) {
+      await page.getByRole('link', { name: 'Scripts', exact: true }).click()
+      await expect(page.getByTestId('scripts-test-heading')).toBeInViewport()
+
+      await page.getByRole('link', { name: 'Home' }).click()
+      await expect(page.getByRole('link', { name: 'Posts' })).toBeVisible()
+    }
+
+    await page.getByRole('link', { name: 'Scripts', exact: true }).click()
+    await expect(page.getByTestId('scripts-test-heading')).toBeInViewport()
+
+    const finalCount = await page.evaluate(() => {
+      return document.querySelectorAll('script[src="script.js"]').length
+    })
+    expect(finalCount).toBe(1)
+
+    expect(await page.evaluate('window.SCRIPT_1')).toBe(true)
+  })
+
+  test('should not create duplicate inline scripts', async ({ page }) => {
+    await page.goto('/inline-scripts')
+
+    await expect(
+      page.getByTestId('inline-scripts-test-heading'),
+    ).toBeInViewport()
+
+    const script1Count = await page.evaluate(() => {
+      const scripts = Array.from(document.querySelectorAll('script:not([src])'))
+      return scripts.filter(
+        (script) =>
+          script.textContent &&
+          script.textContent.includes('window.INLINE_SCRIPT_1 = true'),
+      ).length
+    })
+
+    const script2Count = await page.evaluate(() => {
+      const scripts = Array.from(document.querySelectorAll('script:not([src])'))
+      return scripts.filter(
+        (script) =>
+          script.textContent &&
+          script.textContent.includes('window.INLINE_SCRIPT_2 = "test"'),
+      ).length
+    })
+
+    expect(script1Count).toBe(1)
+    expect(script2Count).toBe(1)
+
+    expect(await page.evaluate('window.INLINE_SCRIPT_1')).toBe(true)
+    expect(await page.evaluate('window.INLINE_SCRIPT_2')).toBe('test')
+  })
+
+  test('should not create duplicate inline scripts during client-side navigation', async ({
+    page,
+  }) => {
+    await page.goto('/')
+
+    await page.getByRole('link', { name: 'Inline Scripts' }).click()
+    await expect(
+      page.getByTestId('inline-scripts-test-heading'),
+    ).toBeInViewport()
+
+    const firstNavScript1Count = await page.evaluate(() => {
+      const scripts = Array.from(document.querySelectorAll('script:not([src])'))
+      return scripts.filter(
+        (script) =>
+          script.textContent &&
+          script.textContent.includes('window.INLINE_SCRIPT_1 = true'),
+      ).length
+    })
+    expect(firstNavScript1Count).toBe(1)
+
+    await page.getByRole('link', { name: 'Home' }).click()
+    await expect(page.getByRole('link', { name: 'Posts' })).toBeVisible()
+
+    await page.getByRole('link', { name: 'Inline Scripts' }).click()
+    await expect(
+      page.getByTestId('inline-scripts-test-heading'),
+    ).toBeInViewport()
+
+    const secondNavScript1Count = await page.evaluate(() => {
+      const scripts = Array.from(document.querySelectorAll('script:not([src])'))
+      return scripts.filter(
+        (script) =>
+          script.textContent &&
+          script.textContent.includes('window.INLINE_SCRIPT_1 = true'),
+      ).length
+    })
+    expect(secondNavScript1Count).toBe(1)
+
+    // Verify the scripts are still working
+    expect(await page.evaluate('window.INLINE_SCRIPT_1')).toBe(true)
+    expect(await page.evaluate('window.INLINE_SCRIPT_2')).toBe('test')
+  })
+})