feat: split runtime/build server entries to exclude static routes from runtime bundle

e2e/fixtures/fs-router-build-split/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "fs-router-build-split",
+  "version": "0.1.0",
+  "type": "module",
+  "private": true,
+  "scripts": {
+    "dev": "waku dev",
+    "build": "waku build",
+    "start": "waku start"
+  },
+  "dependencies": {
+    "react": "~19.2.5",
+    "react-dom": "~19.2.5",
+    "react-server-dom-webpack": "~19.2.5",
+    "waku": "latest"
+  },
+  "devDependencies": {
+    "@types/react": "^19.2.14",
+    "@types/react-dom": "^19.2.3",
+    "typescript": "^6.0.2"
+  }
+}

e2e/fixtures/fs-router-build-split/src/lib/runtime-build-dynamic.ts

@@ -0,0 +1 @@
+export const DYNAMIC_RENDER_SENTINEL = 'PR1974_DYNAMIC_ROUTE_RENDER_SENTINEL';

e2e/fixtures/fs-router-build-split/src/lib/runtime-build-static.ts

@@ -0,0 +1 @@
+export const STATIC_RENDER_SENTINEL = 'PR1974_STATIC_ROUTE_RENDER_SENTINEL';

e2e/fixtures/fs-router-build-split/src/pages/index.tsx

@@ -0,0 +1,3 @@
+export default function Home() {
+  return <h1>Home</h1>;
+}

e2e/fixtures/fs-router-build-split/src/pages/runtime-build-dynamic.tsx

@@ -0,0 +1,9 @@
+import { DYNAMIC_RENDER_SENTINEL } from '../lib/runtime-build-dynamic.js';
+
+export default function RuntimeBuildDynamic() {
+  return <h1>{DYNAMIC_RENDER_SENTINEL}</h1>;
+}
+
+export const getConfig = async () => ({
+  render: 'dynamic' as const,
+});

e2e/fixtures/fs-router-build-split/src/pages/runtime-build-static.tsx

@@ -0,0 +1,9 @@
+import { STATIC_RENDER_SENTINEL } from '../lib/runtime-build-static.js';
+
+export default function RuntimeBuildStatic() {
+  return <h1>{STATIC_RENDER_SENTINEL}</h1>;
+}
+
+export const getConfig = async () => ({
+  render: 'static' as const,
+});

e2e/fixtures/fs-router-build-split/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "target": "esnext",
+    "noEmit": true,
+    "isolatedModules": true,
+    "moduleDetection": "force",
+    "esModuleInterop": true,
+    "module": "esnext",
+    "moduleResolution": "bundler",
+    "skipLibCheck": true,
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+    "jsx": "react-jsx"
+  }
+}

e2e/fixtures/fs-router/src/lib/runtime-build-dynamic.ts

@@ -0,0 +1 @@
+export const DYNAMIC_RENDER_SENTINEL = 'PR1974_DYNAMIC_ROUTE_RENDER_SENTINEL';

e2e/fixtures/fs-router/src/lib/runtime-build-static.ts

@@ -0,0 +1 @@
+export const STATIC_RENDER_SENTINEL = 'PR1974_STATIC_ROUTE_RENDER_SENTINEL';

e2e/fixtures/fs-router/src/pages/runtime-build-dynamic.tsx

@@ -0,0 +1,13 @@
+import { DYNAMIC_RENDER_SENTINEL } from '../lib/runtime-build-dynamic.js';
+
+const RuntimeBuildDynamic = () => {
+  return <h2>{DYNAMIC_RENDER_SENTINEL}</h2>;
+};
+
+export const getConfig = () => {
+  return {
+    render: 'dynamic',
+  } as const;
+};
+
+export default RuntimeBuildDynamic;

e2e/fixtures/fs-router/src/pages/runtime-build-static.tsx

@@ -0,0 +1,13 @@
+import { STATIC_RENDER_SENTINEL } from '../lib/runtime-build-static.js';
+
+const RuntimeBuildStatic = () => {
+  return <h2>{STATIC_RENDER_SENTINEL}</h2>;
+};
+
+export const getConfig = () => {
+  return {
+    render: 'static',
+  } as const;
+};
+
+export default RuntimeBuildStatic;

e2e/fs-router-build-split.spec.ts

@@ -0,0 +1,76 @@
+import { existsSync, readFileSync, readdirSync } from 'node:fs';
+import { join } from 'node:path';
+import { expect } from '@playwright/test';
+import { prepareStandaloneSetup, test } from './utils.js';
+
+const startApp = prepareStandaloneSetup('fs-router-build-split');
+
+const STATIC_RENDER_SENTINEL = 'PR1974_STATIC_ROUTE_RENDER_SENTINEL';
+const DYNAMIC_RENDER_SENTINEL = 'PR1974_DYNAMIC_ROUTE_RENDER_SENTINEL';
+
+const collectDistFiles = (dir: string): string[] => {
+  const files: string[] = [];
+  const queue = [dir];
+
+  while (queue.length) {
+    const current = queue.pop()!;
+    for (const entry of readdirSync(current, { withFileTypes: true })) {
+      const nextPath = join(current, entry.name);
+      if (entry.isDirectory()) {
+        queue.push(nextPath);
+        continue;
+      }
+      files.push(nextPath);
+    }
+  }
+
+  return files;
+};
+
+test.describe('fs-router build split', () => {
+  let port: number;
+  let standaloneDir: string;
+  let stopApp: (() => Promise<void>) | undefined;
+
+  test.beforeAll(async ({ mode }) => {
+    ({ port, stopApp, standaloneDir } = await startApp(mode));
+  });
+
+  test.afterAll(async () => {
+    if (stopApp) {
+      await stopApp();
+    }
+  });
+
+  test('runtime bundle excludes fully static routes while SSG still emits them', async ({
+    mode,
+    page,
+  }) => {
+    test.skip(mode !== 'PRD');
+
+    const distDir = join(standaloneDir, 'dist');
+
+    expect(existsSync(distDir)).toBe(true);
+
+    await page.goto(`http://localhost:${port}/runtime-build-static`);
+    await expect(
+      page.getByRole('heading', { name: STATIC_RENDER_SENTINEL }),
+    ).toBeVisible();
+
+    await page.goto(`http://localhost:${port}/runtime-build-dynamic`);
+    await expect(
+      page.getByRole('heading', { name: DYNAMIC_RENDER_SENTINEL }),
+    ).toBeVisible();
+
+    const serverDistFiles = collectDistFiles(join(distDir, 'server'));
+    const serverJsContents = serverDistFiles
+      .filter((file) => file.endsWith('.js'))
+      .map((file) => readFileSync(file, 'utf8'));
+
+    expect(
+      serverJsContents.some((content) =>
+        content.includes(STATIC_RENDER_SENTINEL),
+      ),
+    ).toBe(false);
+  });
+});