From af7166b74ae1e9bd9a40fadbb76001a7c5ba9728 Mon Sep 17 00:00:00 2001
From: Roman Babenko <roman_babenko@gmx.net>
Date: Thu, 10 Sep 2026 22:55:50 +0200
Subject: [PATCH] feat(native-federation): honor esmsInitOptions.shimMode:false
 for the main script tag

The builder serializes esmsInitOptions into the esms-options tag but
hardcodes the main bundle as <script type="module-shim">, so
shimMode: false is dead on arrival: the browser skips module-shim (an
unknown type), and es-module-shims force-enables shim mode when it sees
any -shim script. A host that wants to run its module graph natively -
for example through @softarc/native-federation-orchestrator with a
native import map - never can.

Emit <script type="module"> when esmsInitOptions.shimMode === false.
With shimMode true or unset the output is byte-for-byte unchanged.
---
 libs/native-federation/src/utils/updateIndexHtml.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libs/native-federation/src/utils/updateIndexHtml.ts b/libs/native-federation/src/utils/updateIndexHtml.ts
index e6378889..aaa726c0 100644
--- a/libs/native-federation/src/utils/updateIndexHtml.ts
+++ b/libs/native-federation/src/utils/updateIndexHtml.ts
@@ -55,6 +55,10 @@ export function updateScriptTags(
     ...nfOptions.esmsInitOptions,
   };
 
+  // A module-shim main tag makes es-module-shims force shim mode back on, so
+  // an explicit shimMode: false must emit a real module script.
+  const mainType = esmsOptions.shimMode === false ? 'module' : 'module-shim';
+
   const htmlFragment = `
 <script type="esms-options">${JSON.stringify(esmsOptions)}</script>
 `;
@@ -65,7 +69,7 @@ export function updateScriptTags(
   );
   indexContent = indexContent.replace(
     /<script\s+src="([^"]*main[^"]*)"[^>]*><\/script>/,
-    '<script type="module-shim" src="$1"></script>',
+    `<script type="${mainType}" src="$1"></script>`,
   );
 
   indexContent = indexContent.replace(/(<body.*?>)/, `$1\n\t\t${htmlFragment}`);