Bugfix. Extract react imports from main bundler to vendor static files

src/functions/bundler/plugins/chunk-react.ts

@@ -0,0 +1,117 @@
+// plugins/react-vendor-chunk-plugin.ts
+import * as esbuild from "esbuild";
+import path from "path";
+import grabDirNames from "../../../utils/grab-dir-names";
+
+const { BUNEXT_VENDOR_DIR } = grabDirNames();
+
+const REACT_MODULES = new Set([
+    "react",
+    "react-dom",
+    "react-dom/client",
+    "react/jsx-runtime",
+    "react/jsx-dev-runtime",
+]);
+
+const VENDOR_BASE = "/.bunext/public/vendor";
+
+const REACT_ENTRIES: Record<string, string> = {
+    react: `
+    import React from "react";
+    export const {
+      Children, Component, Fragment, Profiler, PureComponent, StrictMode,
+      Suspense, cloneElement, createContext, createElement, createFactory,
+      createRef, forwardRef, isValidElement, lazy, memo, startTransition,
+      useCallback, useContext, useDebugValue, useDeferredValue, useEffect,
+      useId, useImperativeHandle, useInsertionEffect, useLayoutEffect,
+      useMemo, useReducer, useRef, useState, useSyncExternalStore,
+      useTransition, version,
+    } = React;
+    export default React;
+  `,
+    "react-dom": `
+    import ReactDOM from "react-dom";
+    export const {
+      createPortal, flushSync, findDOMNode, hydrate, render,
+      unmountComponentAtNode, version,
+    } = ReactDOM;
+    export default ReactDOM;
+  `,
+    "react-dom/client": `
+    import ReactDOMClient from "react-dom/client";
+    export const { createRoot, hydrateRoot } = ReactDOMClient;
+    export default ReactDOMClient;
+  `,
+    "react/jsx-runtime": `
+    import JSXRuntime from "react/jsx-runtime";
+    export const { jsx, jsxs, Fragment } = JSXRuntime;
+    export default JSXRuntime;
+  `,
+    "react/jsx-dev-runtime": `
+    import JSXDevRuntime from "react/jsx-dev-runtime";
+    export const { jsxDEV, Fragment } = JSXDevRuntime;
+    export default JSXDevRuntime;
+  `,
+};
+
+// Map bare specifier -> browser path
+function vendorPath(specifier: string): string {
+    const filename = specifier.replace(/\//g, "_") + ".js";
+    return `${VENDOR_BASE}/${filename}`;
+}
+
+function vendorOutfile(specifier: string): string {
+    const filename = specifier.replace(/\//g, "_") + ".js";
+    return path.join(BUNEXT_VENDOR_DIR, filename);
+}
+
+export default function reactVendorChunkPlugin(): esbuild.Plugin {
+    let vendorReady: Promise<void>;
+
+    return {
+        name: "react-vendor-chunk",
+        setup(build) {
+            vendorReady ??= buildAllVendorChunks(build.initialOptions);
+
+            build.onResolve(
+                { filter: /^react(-dom)?(\/.*)?$/ },
+                async (args) => {
+                    const bare = args.path.replace(/\/index(\.m?js)?$/, "");
+                    if (!(bare in REACT_ENTRIES)) return;
+
+                    await vendorReady;
+
+                    return {
+                        path: vendorPath(bare),
+                        external: true,
+                    };
+                },
+            );
+        },
+    };
+}
+
+async function buildAllVendorChunks(
+    parentOptions: esbuild.BuildOptions,
+): Promise<void> {
+    await Promise.all(
+        Object.entries(REACT_ENTRIES).map(([specifier, contents]) =>
+            esbuild.build({
+                stdin: {
+                    contents,
+                    resolveDir: process.cwd(),
+                    loader: "tsx",
+                },
+                outfile: vendorOutfile(specifier),
+                bundle: true,
+                minify: parentOptions.minify,
+                format: "esm",
+                target: parentOptions.target as string,
+                platform: "browser",
+                define: parentOptions.define,
+                mainFields: ["module", "main"],
+                conditions: ["import", "default"],
+            }),
+        ),
+    );
+}

src/functions/bundler/plugins/react-alias.ts

@@ -0,0 +1,30 @@
+import type { Plugin } from "esbuild";
+import path from "path";
+import grabDirNames from "../../../utils/grab-dir-names";
+
+const { ROOT_DIR } = grabDirNames();
+
+const reactAliasPlugin: Plugin = {
+    name: "react-alias",
+    setup(build) {
+        const reactPath = path.join(ROOT_DIR, "node_modules");
+
+        build.onResolve({ filter: /^react$/ }, () => ({
+            path: path.join(reactPath, "react", "index.js"),
+        }));
+
+        build.onResolve({ filter: /^react-dom$/ }, () => ({
+            path: path.join(reactPath, "react-dom", "index.js"),
+        }));
+
+        build.onResolve({ filter: /^react\/jsx-runtime$/ }, () => ({
+            path: path.join(reactPath, "react", "jsx-runtime.js"),
+        }));
+
+        build.onResolve({ filter: /^react\/jsx-dev-runtime$/ }, () => ({
+            path: path.join(reactPath, "react", "jsx-dev-runtime.js"),
+        }));
+    },
+};
+
+export default reactAliasPlugin;

src/functions/bundler/plugins/virtual-files-plugin.ts

@@ -24,6 +24,22 @@ export default function virtualFilesPlugin({ entryToPage }: Params) {
                 };
             });
 
+            build.onResolve(
+                { filter: /node_modules\/react(-dom)?/ },
+                (args) => ({
+                    path: args.path.includes("react-dom")
+                        ? args.path.includes("client")
+                            ? "react-dom/client"
+                            : "react-dom"
+                        : args.path.includes("jsx-dev")
+                          ? "react/jsx-dev-runtime"
+                          : args.path.includes("jsx")
+                            ? "react/jsx-runtime"
+                            : "react",
+                    external: true,
+                }),
+            );
+
             build.onLoad(
                 { filter: /.*/, namespace: "hydration-virtual" },
                 (args) => {