From 7537badfe5ca4f156e7fd82a732fbf53862377cd Mon Sep 17 00:00:00 2001
From: Alan Agius <17563226+alan-agius4@users.noreply.github.com>
Date: Mon, 3 Mar 2025 11:35:06 +0000
Subject: [PATCH] fix(@schematics/angular): prevent accidental deletion of
 `main.ts` during application builder migration

In certain cases, misconfiguration of the server builder could cause the migration process to incorrectly delete `main.ts`.

Closes: #29661
---
 .../angular/migrations/use-application-builder/migration.ts  | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/schematics/angular/migrations/use-application-builder/migration.ts b/packages/schematics/angular/migrations/use-application-builder/migration.ts
index 40f2740e9463..1ca18961084b 100644
--- a/packages/schematics/angular/migrations/use-application-builder/migration.ts
+++ b/packages/schematics/angular/migrations/use-application-builder/migration.ts
@@ -151,7 +151,10 @@ function* updateBuildTarget(
   // Update server file
   const ssrMainFile = serverTarget?.options?.['main'];
   if (typeof ssrMainFile === 'string') {
-    yield deleteFile(ssrMainFile);
+    // Do not delete the server main file if it's the same as the browser file.
+    if (buildTarget.options?.browser !== ssrMainFile) {
+      yield deleteFile(ssrMainFile);
+    }
 
     yield externalSchematic('@schematics/angular', 'ssr', {
       project: projectName,