test: test stable react vendor chunk

Author: hi-ogawa

packages/rsc/examples/basic/vite.config.ts

@@ -1,9 +1,16 @@
 import assert from "node:assert";
+import { fileURLToPath } from "node:url";
 import { transformHoistInlineDirective } from "@hiogawa/transforms";
 import rsc from "@hiogawa/vite-rsc/plugin";
 import tailwindcss from "@tailwindcss/vite";
 import react from "@vitejs/plugin-react";
-import { type Plugin, defineConfig, parseAstAsync } from "vite";
+import {
+  type Plugin,
+  type Rollup,
+  defineConfig,
+  normalizePath,
+  parseAstAsync,
+} from "vite";
 import inspect from "vite-plugin-inspect";
 
 // log unhandled rejection to debug e2e failures
@@ -126,6 +133,75 @@ export default { fetch: handler };
         }
       },
     },
+    {
+      name: "optimize-chunks",
+      apply: "build",
+      config() {
+        const resolvePackageSource = (source: string) =>
+          normalizePath(fileURLToPath(import.meta.resolve(source)));
+
+        const pkgBrowserPath = resolvePackageSource(
+          "@hiogawa/vite-rsc/react/browser",
+        );
+
+        const manualChunksFn: Rollup.ManualChunksOption = (id) => {
+          // need to use functional form to handle commonjs plugin proxy module
+          // e.g. `(id)?commonjs-es-import`
+          if (
+            id.includes("node_modules/react/") ||
+            id.includes("node_modules/react-dom/") ||
+            id.includes(pkgBrowserPath)
+          ) {
+            return "lib-react";
+          }
+        };
+
+        return {
+          environments: {
+            client: {
+              build: {
+                manifest: true, // for debugging
+                rollupOptions: {
+                  output: {
+                    manualChunks: manualChunksFn,
+                  },
+                },
+              },
+            },
+          },
+        };
+      },
+      // verify chunks are "stable"
+      writeBundle(_options, bundle) {
+        if (this.environment.name === "client") {
+          const entryChunks: Rollup.OutputChunk[] = [];
+          const vendorChunks: Rollup.OutputChunk[] = [];
+          for (const chunk of Object.values(bundle)) {
+            if (chunk.type === "chunk") {
+              if (chunk.facadeModuleId === "\0virtual:vite-rsc/entry-browser") {
+                entryChunks.push(chunk);
+              } else if (chunk.name === "lib-react") {
+                vendorChunks.push(chunk);
+              }
+            }
+          }
+
+          // react vendor chunk has no import
+          assert(vendorChunks.length === 1);
+          assert.deepEqual(
+            vendorChunks[0].imports.filter(
+              (f) => !f.includes("rolldown-runtime"),
+            ),
+            [],
+          );
+          assert.deepEqual(vendorChunks[0].dynamicImports, []);
+
+          // entry chunk has no export
+          assert(entryChunks.length === 1);
+          assert.deepEqual(entryChunks[0].exports, []);
+        }
+      },
+    },
   ],
   build: {
     minify: false,