fix: hmr failed when adding initial chunk (#2743)

e2e/cases/lazy-compilation/add-initial-chunk/index.test.ts

@@ -0,0 +1,17 @@
+import { dev, gotoPage, rspackOnlyTest } from '@e2e/helper';
+import { expect } from '@playwright/test';
+
+// https://github.com/web-infra-dev/rspack/issues/6633
+rspackOnlyTest(
+  'should render pages correctly when using lazy compilation and add new initial chunk',
+  async ({ page }) => {
+    const rsbuild = await dev({
+      cwd: __dirname,
+    });
+
+    await gotoPage(page, rsbuild);
+    await expect(page.locator('#test')).toHaveText('Hello World!');
+
+    rsbuild.close();
+  },
+);

e2e/cases/lazy-compilation/add-initial-chunk/rsbuild.config.ts

@@ -0,0 +1,41 @@
+import { defineConfig } from '@rsbuild/core';
+import { pluginReact } from '@rsbuild/plugin-react';
+
+export default defineConfig({
+  plugins: [pluginReact()],
+  source: {
+    entry: {
+      index: './src/index.js',
+    },
+  },
+  tools: {
+    rspack(config) {
+      config.output ??= {};
+      config.output.asyncChunks = false;
+    },
+  },
+  performance: {
+    chunkSplit: {
+      strategy: 'custom',
+      override: {
+        chunks: 'all',
+        cacheGroups: {
+          lib: {
+            enforce: true,
+            test: /(initial\.js|core-js)/,
+            name: 'lib',
+            chunks: 'all',
+          },
+          default: false,
+          defaultVendors: false,
+        },
+      },
+    },
+  },
+  dev: {
+    lazyCompilation: true,
+  },
+  output: {
+    polyfill: 'usage',
+  },
+});

e2e/cases/lazy-compilation/add-initial-chunk/src/index.js

@@ -0,0 +1,7 @@
+import x from './initial';
+import 'core-js';
+
+const ele = document.createElement('div');
+ele.innerHTML = `Hello ${x}`;
+ele.setAttribute('id', 'test');
+document.body.append(ele);

e2e/cases/lazy-compilation/add-initial-chunk/src/initial.js

@@ -0,0 +1,3 @@
+import 'core-js/package.json';
+
+export default 'World!';

packages/core/src/server/socketServer.ts

@@ -9,6 +9,19 @@ interface ExtWebSocket extends Ws {
   isAlive: boolean;
 }
 
+function isEqualSet(a: Set<string>, b: Set<string>): boolean {
+  if (a.size !== b.size) {
+    return false;
+  }
+
+  for (const v of a.values()) {
+    if (!b.has(v)) {
+      return false;
+    }
+  }
+  return true;
+}
+
 export class SocketServer {
   private wsServer!: Ws.Server;
 
@@ -17,6 +30,7 @@ export class SocketServer {
   private readonly options: DevConfig;
 
   private stats?: Stats;
+  private initialChunks?: Set<string>;
 
   private timer: ReturnType<typeof setInterval> | null = null;
 
@@ -151,6 +165,7 @@ export class SocketServer {
       errors: true,
       errorsCount: true,
       errorDetails: false,
+      entrypoints: true,
       children: true,
     };
 
@@ -166,6 +181,29 @@ export class SocketServer {
       return null;
     }
 
+    // web-infra-dev/rspack#6633
+    // when initial-chunks change, reload the page
+    // e.g: ['index.js'] -> ['index.js', 'lib-polyfill.js']
+    const newInitialChunks: Set<string> = new Set();
+    if (stats.entrypoints) {
+      for (const entrypoint of Object.values(stats.entrypoints)) {
+        const chunks = entrypoint.chunks;
+        if (Array.isArray(chunks)) {
+          for (const chunkName of chunks) {
+            chunkName && newInitialChunks.add(chunkName);
+          }
+        }
+      }
+    }
+    const shouldReload =
+      Boolean(stats.entrypoints) &&
+      Boolean(this.initialChunks) &&
+      !isEqualSet(this.initialChunks as Set<string>, newInitialChunks);
+    this.initialChunks = newInitialChunks;
+    if (shouldReload) {
+      return this.sockWrite('content-changed');
+    }
+
     const shouldEmit =
       !force &&
       stats &&