From c08335af23e2c3e8e7d2da59b91fa69c3f749c0f Mon Sep 17 00:00:00 2001
From: Mikael Grankvist <mikael.grankvist@vaadin.com>
Date: Tue, 14 Sep 2021 14:11:31 +0300
Subject: [PATCH] fix: Only write package.json if something actually changed

Flag update of vaadin version as an addition
also and only write the package.json if
thee was an actual change in content.

Fixes #11259
---
 .../java/com/vaadin/flow/server/frontend/NodeUpdater.java     | 4 ++++
 .../vaadin/flow/server/frontend/TaskCreatePackageJson.java    | 4 +++-
 .../flow/server/frontend/AbstractNodeUpdatePackagesTest.java  | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/flow-server/src/main/java/com/vaadin/flow/server/frontend/NodeUpdater.java b/flow-server/src/main/java/com/vaadin/flow/server/frontend/NodeUpdater.java
index 12908ed12dd..d17b16ed10b 100644
--- a/flow-server/src/main/java/com/vaadin/flow/server/frontend/NodeUpdater.java
+++ b/flow-server/src/main/java/com/vaadin/flow/server/frontend/NodeUpdater.java
@@ -420,6 +420,10 @@ private int handleExistingVaadinDep(JsonObject json, String pkg,
 
         if (added) {
             log().debug("Added \"{}\": \"{}\" line.", pkg, version);
+        } else {
+            // we made a change to the package json vaadin defaults
+            // even if we didn't add to the dependencies.
+            added = !vaadinVersion.isEqualTo(newVersion);
         }
         return added ? 1 : 0;
     }
diff --git a/flow-server/src/main/java/com/vaadin/flow/server/frontend/TaskCreatePackageJson.java b/flow-server/src/main/java/com/vaadin/flow/server/frontend/TaskCreatePackageJson.java
index 1c434ccc5a6..6044145ddb5 100644
--- a/flow-server/src/main/java/com/vaadin/flow/server/frontend/TaskCreatePackageJson.java
+++ b/flow-server/src/main/java/com/vaadin/flow/server/frontend/TaskCreatePackageJson.java
@@ -48,7 +48,9 @@ public void execute() {
             modified = false;
             JsonObject mainContent = getPackageJson();
             modified = updateDefaultDependencies(mainContent);
-            writePackageFile(mainContent);
+            if(modified) {
+                writePackageFile(mainContent);
+            }
         } catch (IOException e) {
             throw new UncheckedIOException(e);
         }
diff --git a/flow-server/src/test/java/com/vaadin/flow/server/frontend/AbstractNodeUpdatePackagesTest.java b/flow-server/src/test/java/com/vaadin/flow/server/frontend/AbstractNodeUpdatePackagesTest.java
index 2328318e709..b85fb341fe2 100644
--- a/flow-server/src/test/java/com/vaadin/flow/server/frontend/AbstractNodeUpdatePackagesTest.java
+++ b/flow-server/src/test/java/com/vaadin/flow/server/frontend/AbstractNodeUpdatePackagesTest.java
@@ -292,7 +292,7 @@ public void oldVaadinDevDependency_missmatchWithDevDependency_vaadinDependencyIs
         final String version = packageUpdater.getDefaultDevDependencies()
                 .get(key);
         json.getObject(VAADIN_DEP_KEY).getObject(DEV_DEPENDENCIES)
-                .put(key, "4.42.0");
+                .put(key, "3.42.0");
         json.getObject(DEV_DEPENDENCIES).put(key, version);
 
         Files.write(packageJson.toPath(),