Remove MessageChannel shim #2247

build.gradle

@@ -121,17 +121,8 @@ tasks.register('bundleReactForTest', NpmTask) {
     environment = ['FORCE_COLOR': 'true']
 }
 
-tasks.register('bundleReactServerBrowserForTest', NpmTask) {
-    dependsOn npmInstall
-    args = ['run', 'build:react-server-browser-test-bundle']
-    inputs.file('src/test/js/react-bundle-server-browser-entry.js')
-    inputs.file('package-lock.json')
-    outputs.file('build/resources/test/test-fixtures/react-bundle-server-browser.js')
-    environment = ['FORCE_COLOR': 'true']
-}
-
 test {
-    dependsOn bundleReactForTest, bundleReactServerBrowserForTest
+    dependsOn bundleReactForTest
     useJUnitPlatform {
     }
 }

package.json

@@ -94,7 +94,6 @@
     "postcov": "npm run lcov",
     "reinstall": "npm run clean && npm run local",
     "build:react-test-bundle": "esbuild src/test/js/react-bundle-entry.js --bundle --format=iife --platform=neutral --define:process.env.NODE_ENV=\\\"production\\\" --outfile=build/resources/test/test-fixtures/react-bundle.js",
-    "build:react-server-browser-test-bundle": "esbuild src/test/js/react-bundle-server-browser-entry.js --bundle --format=iife --platform=neutral --define:process.env.NODE_ENV=\\\"production\\\" --outfile=build/resources/test/test-fixtures/react-bundle-server-browser.js",
     "rollup:nodePolyfills": "npx rollup --config rollup.config.nodePolyfills.mjs",
     "test": "npm run test:jest && npm run test:deno",
     "test:deno": "deno test --coverage=build/deno/coverage --env-file=src/deno/.env --importmap=src/deno/importmap.json --no-check src/deno/**/*.test.ts",

src/main/resources/lib/enonic/polyfill-react4xp/nodePolyfills.ts

@@ -9,23 +9,6 @@ import {TextEncoder} from '@sinonjs/text-encoding';
 import 'core-js/modules/web.atob.js';
 import 'core-js/modules/web.btoa.js';
 
-// Transitional MessageChannel shim: react-dom/server.browser constructs a
-// MessageChannel at module-load time (unconditionally, before any render call) for
-// its streaming scheduler. With this minimal polyfill, the module loads and
-// renderToString — which doesn't touch the channel — works.
-//
-// LIMITATIONS: postMessage is intentionally a no-op. The streaming APIs
-// (renderToReadableStream, prerender) WILL silently hang because the no-op timers
-// can never deliver messages. For streaming, consumers must use
-// react-dom/server.edge (which has no MessageChannel dependency).
-//
-// Remove this once @enonic/react4xp's webpack config aliases react-dom/server to
-// react-dom/server.edge — see https://github.com/facebook/react/issues/31827
-function MessagePortShim(this: { onmessage: ((ev: { data: unknown }) => void) | null; postMessage: (data: unknown) => void }) {
-	this.onmessage = null;
-	this.postMessage = function () { /* no-op: SSR has no async */ };
-}
-
 (function (context) {
 	//──────────────────────────────────────────────────────────────────────────
 	// Timers: When doing SSR it makes no sense to do anything asyncronously.
@@ -38,17 +21,5 @@ function MessagePortShim(this: { onmessage: ((ev: { data: unknown }) => void) |
 	if (typeof context['TextEncoder'] === 'undefined') {
 		context['TextEncoder'] = TextEncoder;
 	}
-
-	//──────────────────────────────────────────────────────────────────────────
-	// MessageChannel: see comment above MessagePortShim.
-	//──────────────────────────────────────────────────────────────────────────
-	if (typeof context['MessageChannel'] === 'undefined') {
-		context['MessageChannel'] = function MessageChannel(this: { port1: object; port2: object }) {
-			// @ts-expect-error TS2350: 'new' expression with non-constructor type.
-			this.port1 = new MessagePortShim();
-			// @ts-expect-error TS2350: 'new' expression with non-constructor type.
-			this.port2 = new MessagePortShim();
-		};
-	}
 //@ts-expect-error TS2695: Left side of comma operator is unused and has no side effects.
 })((1, eval)('this') as Partial<ContextWithTimers>);

src/test/java/com/enonic/lib/react4xp/ssr/renderer/RendererTest.java

@@ -144,36 +144,6 @@ void render_real_react_component_via_server_edge()
         }
     }
 
-    @Test
-    void render_real_react_component_via_server_browser_with_message_channel_shim()
-    {
-        // server.browser constructs `new MessageChannel()` at module-load time. This test
-        // pins the contract that the transitional shim in nodePolyfills.ts lets the module
-        // load and that renderToString (via server-legacy.browser) produces HTML.
-        final String reactBundle = readClasspathResource( "/test-fixtures/react-bundle-server-browser.js" );
-
-        final Map<String, String> fixtures = new HashMap<>();
-        fixtures.put( POLYFILL_BASICS, readClasspathResource( POLYFILL_BASICS ) );
-        fixtures.put( POLYFILL_NODE, readClasspathResource( POLYFILL_NODE ) );
-        fixtures.put( CHUNKS_GLOBALS_JSON, "{ \"main\": { \"js\": \"globals.js\" } }" );
-        fixtures.put( GLOBALS_JS,
-                      reactBundle + "\n" + "globalThis.React4xp = {" + "  '_components/Greeter': {" + "    default: function(props) {" +
-                          "      return React.createElement('h1', null, 'Hello, ' + props.name + '!');" + "    }" + "  }" + "};" );
-
-        final Renderer renderer = new Renderer( strictReader( fixtures ), testConfig(), 11L, engine, freshSource() );
-        try
-        {
-            final Map<String, String> result = renderer.render( "_components/Greeter", "{\"name\":\"World\"}", new String[0] );
-
-            assertNull( result.get( KEY_ERROR ), "expected success, got error: " + result.get( KEY_ERROR ) );
-            assertEquals( "<h1>Hello, World!</h1>", result.get( KEY_HTML ) );
-        }
-        finally
-        {
-            renderer.close();
-        }
-    }
-
     @Test
     void render_unknown_entry_propagates_illegal_state()
     {