Back out "ESM plugin bundles"

Summary:
Original commit changeset: 2a60315dd5c0

Original Phabricator Diff: D50015827

Reviewed By: lblasa

Differential Revision: D50168201

fbshipit-source-id: 3430c37b0aa6a5e3a5ec35fb4c54f01899236173

desktop/flipper-server-core/src/server/startServer.tsx

@@ -177,13 +177,6 @@ async function startHTTPServer(
     res.end('flipper-ok');
   });
 
-  // In dev plugins are served with paths from their location on disk
-  if (process.env.NODE_ENV !== 'production') {
-    app.use(
-      express.static(config.staticPath.split('/').slice(0, -1).join('/')),
-    );
-  }
-
   app.use(express.static(config.staticPath));
 
   const server = http.createServer(app);

desktop/flipper-ui-browser/src/initializeRenderHost.tsx

@@ -177,19 +177,25 @@ export function initializeRenderHost(
     },
     flipperServer,
     async requirePlugin(path): Promise<{plugin: any; css?: string}> {
-      /** path to bundle.js from project root */
-      const staticPath = path.includes('/static/')
-        ? path.split('/static/', 2).pop()
-        : path.split('/desktop/', 2).pop();
-      // This is a string as server side is transpiled by typescript.
-      // Typescript transpiles dynamic import calls to `require` in the browser bundle
-      // We want to explicilty use dynamic import here
-      const importStr = `import('/${staticPath}?ts=${Date.now()}')`;
       const source = await flipperServer.exec('plugin-source', path);
-      // eslint-disable-next-line no-eval
-      const importRes = await eval(importStr);
 
-      return {plugin: importRes, css: source.css};
+      let js = source.js;
+      // append source url (to make sure a file entry shows up in the debugger)
+      js += `\n//# sourceURL=file://${path}`;
+      if (isProduction()) {
+        // and source map url (to get source code if available)
+        js += `\n//# sourceMappingURL=file://${path}.map`;
+      }
+
+      // Plugins are compiled as typical CJS modules, referring to the global
+      // 'module', which we'll make available by loading the source into a closure that captures 'module'.
+      // Note that we use 'eval', and not 'new Function', because the latter will cause the source maps
+      // to be off by two lines (as the function declaration uses two lines in the generated source)
+      // eslint-disable-next-line no-eval
+      const cjsLoader = eval('(module) => {' + js + '\n}');
+      const theModule = {exports: {}};
+      cjsLoader(theModule);
+      return {plugin: theModule.exports, css: source.css};
     },
     getStaticResourceUrl(path): string {
       // the 'static' folder is mounted as static middleware in Express at the root

desktop/flipper-ui-core/src/dispatcher/plugins.tsx

@@ -122,7 +122,7 @@ export default async (store: Store, _logger: Logger) => {
     FlipperPlugin,
     Immer,
     antd,
-    emotion_styled: emotion_styled.default,
+    emotion_styled,
     emotion_css,
     antdesign_icons,
     ReactJsxRuntime,

desktop/pkg-lib/src/runBuild.tsx

@@ -28,53 +28,6 @@ const resolveFbStubsToFbPlugin: Plugin = {
   },
 };
 
-const globalFallbackPlugin: Plugin = {
-  name: 'global-fallback',
-  setup(build) {
-    const pluginExternalModules: Record<string, string> = {
-      flipper: 'Flipper',
-      'flipper-plugin': 'FlipperPlugin',
-      react: 'React',
-      'react-dom': 'ReactDOM',
-      'react-dom/client': 'ReactDOMClient',
-      'react-is': 'ReactIs',
-      antd: 'antd',
-      immer: 'Immer',
-      '@emotion/styled': 'emotion_styled',
-      '@emotion/css': 'emotion_css',
-      '@ant-design/icons': 'antdesign_icons',
-      'react/jsx-runtime': 'ReactJsxRuntime',
-    };
-
-    // Filter and modify the resolution of certain paths
-    build.onResolve(
-      {
-        filter: new RegExp(
-          `^(${Object.keys(pluginExternalModules).join('|')})$`,
-        ),
-      },
-      (args) => {
-        return {
-          path: args.path,
-          namespace: 'global-fallback',
-        };
-      },
-    );
-
-    // Load the module using the global fallback
-    build.onLoad({filter: /.*/, namespace: 'global-fallback'}, (args) => {
-      const globalName = pluginExternalModules[args.path];
-      return {
-        // contents: `export default window["${globalName}"];`,
-        contents: `const mod = window["${globalName}"];
-          for (const key in mod) {
-            exports[key] = mod[key];
-          }`,
-      };
-    });
-  },
-};
-
 interface RunBuildConfig {
   pluginDir: string;
   entry: string;
@@ -99,7 +52,7 @@ async function runBuild({
     bundle: true,
     outfile: out,
     platform: node ? 'node' : 'browser',
-    format: 'esm',
+    format: 'cjs',
     // This list should match `dispatcher/plugins.tsx` and `builtInModules` in `desktop/.eslintrc.js`
     external: [
       'flipper',
@@ -120,10 +73,7 @@ async function runBuild({
     ],
     sourcemap: dev ? 'inline' : 'external',
     minify: !dev,
-    plugins: [
-      ...(intern ? [resolveFbStubsToFbPlugin] : []),
-      globalFallbackPlugin,
-    ],
+    plugins: intern ? [resolveFbStubsToFbPlugin] : undefined,
     loader: {
       '.ttf': 'dataurl',
     },