perf: Optimise render counts

packages/e2e/next/cypress/e2e/shared/render-count.cy.ts

@@ -0,0 +1,57 @@
+import { testRenderCount } from 'e2e-shared/specs/render-count.cy'
+
+const hooks = ['useQueryState', 'useQueryStates'] as const
+const shallows = [true, false] as const
+const histories = ['replace', 'push'] as const
+
+for (const hook of hooks) {
+  for (const shallow of shallows) {
+    for (const history of histories) {
+      for (const startTransition of [false, true]) {
+        for (const delay of shallow === false ? [0, 50] : [0]) {
+          testRenderCount({
+            path: `/app/render-count/${hook}/${shallow}/${history}/${startTransition}?delay=${delay}`,
+            hook,
+            props: {
+              shallow,
+              history,
+              startTransition,
+              delay
+            },
+            expected: {
+              mount: 1,
+              update: shallow === false ? 3 : 2
+            },
+            nextJsRouter: 'app'
+          })
+        }
+      }
+    }
+  }
+}
+
+for (const hook of hooks) {
+  for (const shallow of shallows) {
+    for (const history of histories) {
+      for (const startTransition of [false, true]) {
+        for (const delay of shallow === false ? [0, 50] : [0]) {
+          testRenderCount({
+            path: `/pages/render-count/${hook}/${shallow}/${history}/${startTransition}?delay=${delay}`,
+            hook,
+            props: {
+              shallow,
+              history,
+              startTransition,
+              delay
+            },
+            expected: {
+              mount: 1,
+              update: 2
+            },
+            nextJsRouter: 'pages'
+          })
+        }
+      }
+    }
+  }
+}

packages/e2e/next/package.json

@@ -16,7 +16,7 @@
     "start": "NODE_OPTIONS='--enable-source-maps=true' next start --port 3001",
     "pretest": "cypress install",
     "test": "start-server-and-test start http://localhost:3001${BASE_PATH} cypress:run",
-    "cypress:open": "cypress open",
+    "cypress:open": "cypress open --e2e --browser electron",
     "cypress:run": "cypress run --headless"
   },
   "dependencies": {

packages/e2e/next/src/app/app/(shared)/render-count/[hook]/[shallow]/[history]/[startTransition]/page.tsx

@@ -0,0 +1,47 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import {
+  loadParams,
+  loadSearchParams
+} from 'e2e-shared/specs/render-count.params'
+import { setTimeout } from 'node:timers/promises'
+import { type SearchParams } from 'nuqs/server'
+import { Suspense } from 'react'
+
+export const dynamic = 'force-dynamic'
+
+type PageProps = {
+  params: Promise<Record<keyof ReturnType<typeof loadParams>, string>>
+  searchParams: Promise<SearchParams>
+}
+
+export default async function Page({
+  params,
+  searchParams
+}: PageProps & { searchParams: Promise<SearchParams> }) {
+  const { hook, shallow, history, startTransition } = await loadParams(params)
+  const { delay } = await loadSearchParams(searchParams)
+  if (delay) {
+    await setTimeout(delay)
+  }
+  return (
+    <Suspense>
+      <RenderCount
+        hook={hook}
+        shallow={shallow}
+        history={history}
+        startTransition={startTransition}
+      />
+    </Suspense>
+  )
+}
+
+export async function generateStaticParams() {
+  const hooks = ['useQueryState', 'useQueryStates']
+  const shallow = [true, false]
+  const history = ['push', 'replace']
+  return hooks.flatMap(hook =>
+    shallow.flatMap(shallow =>
+      history.map(history => ({ hook, shallow: shallow.toString(), history }))
+    )
+  )
+}

packages/e2e/next/src/pages/pages/render-count/[hook]/[shallow]/[history]/[startTransition]/index.tsx

@@ -0,0 +1,25 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import {
+  loadParams,
+  loadSearchParams,
+  type Params
+} from 'e2e-shared/specs/render-count.params'
+import { GetServerSideProps } from 'next'
+import { setTimeout } from 'node:timers/promises'
+
+export default RenderCount
+
+// We need SSR to get the correct initial render counts
+// otherwise with SSG we get at least one extra render for hydration.
+export const getServerSideProps: GetServerSideProps<Params> = async ({
+  params,
+  query
+}) => {
+  const { delay } = loadSearchParams(query)
+  if (delay) {
+    await setTimeout(delay)
+  }
+  return {
+    props: loadParams(params!)
+  }
+}

packages/e2e/react-router/v6/cypress/e2e/shared/render-count.cy.ts

@@ -0,0 +1,80 @@
+import { testRenderCount } from 'e2e-shared/specs/render-count.cy'
+
+const hooks = ['useQueryState', 'useQueryStates'] as const
+const shallows = [true, false] as const
+const histories = ['replace', 'push'] as const
+
+for (const hook of hooks) {
+  for (const shallow of shallows) {
+    for (const history of histories) {
+      for (const startTransition of [false, true]) {
+        testRenderCount({
+          path: `/render-count/${hook}/${shallow}/${history}/${startTransition}/no-loader`,
+          description: 'no loader',
+          hook,
+          props: {
+            shallow,
+            history,
+            startTransition
+          },
+          expected: {
+            mount: 1,
+            update: 2 + (shallow === false ? (startTransition ? 0 : 1) : 0)
+          }
+        })
+      }
+    }
+  }
+}
+
+for (const hook of hooks) {
+  for (const shallow of shallows) {
+    for (const history of histories) {
+      for (const startTransition of [false, true]) {
+        testRenderCount({
+          path: `/render-count/${hook}/${shallow}/${history}/${startTransition}/sync-loader`,
+          description: 'sync loader',
+          hook,
+          props: {
+            shallow,
+            history,
+            startTransition
+          },
+          expected: {
+            mount: 1,
+            update: 2 + (shallow === false ? 1 : 0)
+          }
+        })
+      }
+    }
+  }
+}
+
+for (const hook of hooks) {
+  for (const shallow of shallows) {
+    for (const history of histories) {
+      for (const startTransition of [false, true]) {
+        for (const delay of shallow === false ? [0, 50] : [0]) {
+          testRenderCount({
+            path: `/render-count/${hook}/${shallow}/${history}/${startTransition}/async-loader?delay=${delay}`,
+            description: 'async loader',
+            hook,
+            props: {
+              shallow,
+              history,
+              startTransition,
+              delay
+            },
+            expected: {
+              mount: 1,
+              update:
+                2 +
+                (shallow === false ? 1 : 0) +
+                (!startTransition && delay ? 1 : 0)
+            }
+          })
+        }
+      }
+    }
+  }
+}

packages/e2e/react-router/v6/src/react-router.tsx

@@ -41,6 +41,11 @@ const router = createBrowserRouter(
       <Route path="form/useQueryStates"                   lazy={load(import('./routes/form.useQueryStates'))} />
       <Route path="referential-stability/useQueryState"   lazy={load(import('./routes/referential-stability.useQueryState'))} />
       <Route path="referential-stability/useQueryStates"  lazy={load(import('./routes/referential-stability.useQueryStates'))} />
+
+      <Route path="render-count/:hook/:shallow/:history/:startTransition/no-loader"     lazy={load(import('./routes/render-count.$hook.$shallow.$history.$startTransition.no-loader'))} />
+      <Route path="render-count/:hook/:shallow/:history/:startTransition/sync-loader"   lazy={load(import('./routes/render-count.$hook.$shallow.$history.$startTransition.sync-loader'))} />
+      <Route path="render-count/:hook/:shallow/:history/:startTransition/async-loader"  lazy={load(import('./routes/render-count.$hook.$shallow.$history.$startTransition.async-loader'))} />
+
       {/* Reproductions */}
       <Route path='repro-839'   lazy={load(import('./routes/repro-839'))} />
     </Route>

packages/e2e/react-router/v6/src/routes/render-count.$hook.$shallow.$history.$startTransition.async-loader.tsx

@@ -0,0 +1,22 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import {
+  loadParams,
+  loadSearchParams
+} from 'e2e-shared/specs/render-count.params'
+
+import { useParams, type LoaderFunctionArgs } from 'react-router-dom'
+
+const wait = (ms: number) => new Promise(resolve => setTimeout(resolve, ms))
+
+export async function loader({ request }: LoaderFunctionArgs) {
+  const { delay } = loadSearchParams(request)
+  if (delay) {
+    await wait(delay)
+  }
+  return null
+}
+
+export default function Page() {
+  const params = loadParams(useParams())
+  return <RenderCount {...params} />
+}

packages/e2e/react-router/v6/src/routes/render-count.$hook.$shallow.$history.$startTransition.no-loader.tsx

@@ -0,0 +1,8 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import { loadParams } from 'e2e-shared/specs/render-count.params'
+import { useParams } from 'react-router-dom'
+
+export default function Page() {
+  const params = loadParams(useParams())
+  return <RenderCount {...params} />
+}

packages/e2e/react-router/v6/src/routes/render-count.$hook.$shallow.$history.$startTransition.sync-loader.tsx

@@ -0,0 +1,12 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import { loadParams } from 'e2e-shared/specs/render-count.params'
+import { useParams } from 'react-router-dom'
+
+export function loader() {
+  return null
+}
+
+export default function Page() {
+  const params = loadParams(useParams())
+  return <RenderCount {...params} />
+}

packages/e2e/react-router/v7/app/routes.ts

@@ -24,6 +24,9 @@ export default [
     route('/form/useQueryStates',                   './routes/form.useQueryStates.tsx'),
     route('/referential-stability/useQueryState',   './routes/referential-stability.useQueryState.tsx'),
     route('/referential-stability/useQueryStates',  './routes/referential-stability.useQueryStates.tsx'),
+    route('/render-count/:hook/:shallow/:history/:startTransition/no-loader',    './routes/render-count.$hook.$shallow.$history.$startTransition.no-loader.tsx'),
+    route('/render-count/:hook/:shallow/:history/:startTransition/sync-loader',  './routes/render-count.$hook.$shallow.$history.$startTransition.sync-loader.tsx'),
+    route('/render-count/:hook/:shallow/:history/:startTransition/async-loader', './routes/render-count.$hook.$shallow.$history.$startTransition.async-loader.tsx'),
     // Reproductions
     route('/repro-839',   './routes/repro-839.tsx'),
   ])

packages/e2e/react-router/v7/app/routes/render-count.$hook.$shallow.$history.$startTransition.async-loader.tsx

@@ -0,0 +1,20 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import {
+  loadParams,
+  loadSearchParams
+} from 'e2e-shared/specs/render-count.params'
+import { setTimeout } from 'node:timers/promises'
+import { useParams, type LoaderFunctionArgs } from 'react-router'
+
+export async function loader({ request }: LoaderFunctionArgs) {
+  const { delay } = loadSearchParams(request)
+  if (delay) {
+    await setTimeout(delay)
+  }
+  return null
+}
+
+export default function Page() {
+  const params = loadParams(useParams())
+  return <RenderCount {...params} />
+}

packages/e2e/react-router/v7/app/routes/render-count.$hook.$shallow.$history.$startTransition.no-loader.tsx

@@ -0,0 +1,8 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import { loadParams } from 'e2e-shared/specs/render-count.params'
+import { useParams } from 'react-router'
+
+export default function Page() {
+  const params = loadParams(useParams())
+  return <RenderCount {...params} />
+}

packages/e2e/react-router/v7/app/routes/render-count.$hook.$shallow.$history.$startTransition.sync-loader.tsx

@@ -0,0 +1,12 @@
+import { RenderCount } from 'e2e-shared/specs/render-count'
+import { loadParams } from 'e2e-shared/specs/render-count.params'
+import { useParams } from 'react-router'
+
+export function loader() {
+  return null
+}
+
+export default function Page() {
+  const params = loadParams(useParams())
+  return <RenderCount {...params} />
+}