fix(enhanced): rehydrate bundler runtime in web workers (#4417)

ScriptedAlchemy · cursoragent · web-flow · commit 01724916587e · 2026-02-24T17:32:16.000+08:00
Co-authored-by: Cursor Agent &lt;cursoragent@cursor.com&gt;
Co-authored-by: Zack Jackson &lt;ScriptedAlchemy@users.noreply.github.com&gt;
diff --git a/.changeset/sharp-crabs-sing.md b/.changeset/sharp-crabs-sing.md
@@ -0,0 +1,5 @@
+---
+"@module-federation/enhanced": patch
+---
+
+Fix federation runtime bootstrap to rehydrate bundler runtime in workers.
diff --git a/packages/enhanced/src/lib/container/runtime/FederationRuntimePlugin.ts b/packages/enhanced/src/lib/container/runtime/FederationRuntimePlugin.ts
@@ -136,7 +136,7 @@ class FederationRuntimePlugin {
       });
     }
     const embedRuntimeLines = Template.asString([
-      `if(!${federationGlobal}.runtime){`,
+      `if(!${federationGlobal}.runtime || !${federationGlobal}.bundlerRuntime){`,
       Template.indent([
         `var prevFederation = ${federationGlobal};`,
         `${federationGlobal} = {}`,
diff --git a/packages/enhanced/test/unit/container/FederationRuntimePlugin.test.ts b/packages/enhanced/test/unit/container/FederationRuntimePlugin.test.ts
@@ -188,4 +188,19 @@ describe('FederationRuntimePlugin runtimePluginCalls', () => {
       expect(template).toContain('plugin_0 ? (plugin_0.default || plugin_0)');
     });
   });
+
+  describe('runtime bootstrap guards', () => {
+    it('rehydrates bundler runtime when runtime exists but bundlerRuntime is missing', () => {
+      const template = FederationRuntimePlugin.getTemplate(
+        compiler as Compiler,
+        mockOptions,
+        'bundler-runtime.js',
+        {},
+      );
+
+      expect(template).toContain(
+        'if(!__webpack_require__.federation.runtime || !__webpack_require__.federation.bundlerRuntime)',
+      );
+    });
+  });
 });

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"@module-federation/enhanced": patch
 +---
++
 +Fix federation runtime bootstrap to rehydrate bundler runtime in workers.
Original file line number	Diff line number	Diff line change
`@@ -136,7 +136,7 @@ class FederationRuntimePlugin {`
`136`	`136`	`});`
`137`	`137`	`}`
`138`	`138`	`const embedRuntimeLines = Template.asString([`
`139`		- `if(!${federationGlobal}.runtime){`,
	`139`	+ `if(!${federationGlobal}.runtime \|\| !${federationGlobal}.bundlerRuntime){`,
`140`	`140`	`Template.indent([`
`141`	`141`	`var prevFederation = ${federationGlobal};`,
`142`	`142`	`${federationGlobal} = {}`,