From 6fc824b4cb9a86b1e80d427d4b4e844c131deea7 Mon Sep 17 00:00:00 2001
From: Guillaume Nodet <gnodet@gmail.com>
Date: Thu, 7 May 2026 16:01:59 +0200
Subject: [PATCH 1/2] chore: conditionally enable OpenRewrite per module via
 marker files
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Instead of always running OpenRewrite on all modules (which adds ~8 min
to every build), use Maven file-activated profiles to run it only on
modules with changed Java files.

Before the build, regen.sh creates .rewrite-enabled marker files in
modules that have modified Java files. The rewrite profile in parent/pom.xml
activates when this file exists, so OpenRewrite runs only where needed.

This approach is recipe-agnostic — adding new OpenRewrite recipes to
the profile requires no changes to the detection logic.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .gitignore           |  3 ++-
 etc/scripts/regen.sh | 18 ++++++++++++++++++
 parent/pom.xml       |  5 +++++
 pom.xml              |  1 +
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index e871c05ad7470..f21b36a36f8f7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,4 +33,5 @@ mvnd.zip*
 backlog
 .claude
 .omc
-.oss-ai-helper-rules
\ No newline at end of file
+.oss-ai-helper-rules
+.rewrite-enabled
diff --git a/etc/scripts/regen.sh b/etc/scripts/regen.sh
index 5f4b75f2a69b0..e710691240b9d 100755
--- a/etc/scripts/regen.sh
+++ b/etc/scripts/regen.sh
@@ -25,6 +25,24 @@ cd `dirname "$0"`/../..
 git clean -fdx
 rm -Rf **/src/generated/
 
+# Enable OpenRewrite only for modules with changed Java files.
+# Maven's file-activated profile (<exists>.rewrite-enabled</exists>) checks
+# per-module, so OpenRewrite runs only where needed — no -Prewrite flag required.
+# We only need --deepen=1 (depth 1 -> 2) since we compare adjacent commits:
+# for PRs, HEAD~1 is the base branch tip (first parent of the merge commit);
+# for main builds, HEAD~1 is the previous squash-merged commit.
+if ! git rev-parse HEAD~1 >/dev/null 2>&1; then
+  git fetch --deepen=1 --quiet 2>/dev/null || true
+fi
+
+if git rev-parse HEAD~1 >/dev/null 2>&1; then
+  git diff HEAD~1 HEAD --name-only -- '*.java' ':!*/src/generated/*' \
+    | sed 's|/src/.*||' | sort -u \
+    | while read module; do
+        [ -d "$module" ] && touch "$module/.rewrite-enabled"
+      done
+fi
+
 # Regenerate everything
 if ./mvnw --batch-mode -Pregen -DskipTests ${MAVEN_EXTRA_ARGS} install >> build.log 2>&1; then
   echo "✅ mvn -Pregen succeeded."
diff --git a/parent/pom.xml b/parent/pom.xml
index 3cc1d9705782a..2c1a4e7e22216 100644
--- a/parent/pom.xml
+++ b/parent/pom.xml
@@ -4183,6 +4183,11 @@
 
         <profile>
             <id>rewrite</id>
+            <activation>
+                <file>
+                    <exists>.rewrite-enabled</exists>
+                </file>
+            </activation>
             <build>
                 <plugins>
                     <plugin>
diff --git a/pom.xml b/pom.xml
index bf74fe541a446..09060bbd3f5b4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -261,6 +261,7 @@
                                     ${maven.multiModuleProjectDirectory}/buildingtools/src/main/resources/header.txt
                                 </header>
                                 <excludes>
+                                    <exclude>**/.rewrite-enabled</exclude>
                                     <exclude>release.properties</exclude>
                                     <exclude>**/pom.xml.tag</exclude>
                                     <exclude>**/pom.xml.releaseBackup</exclude>

From 0c60ce4eeeb2dbecccc511c17808aa31b6e3d7db Mon Sep 17 00:00:00 2001
From: Guillaume Nodet <gnodet@gmail.com>
Date: Mon, 11 May 2026 14:49:37 +0200
Subject: [PATCH 2/2] =?UTF-8?q?test:=20Java=20change=20in=20camel-api=20?=
 =?UTF-8?q?=E2=80=94=20OpenRewrite=20should=20run=20for=20this=20module=20?=
 =?UTF-8?q?only?=
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DO NOT MERGE — test PR to validate .rewrite-enabled marker is created only for core/camel-api.
---
 core/camel-api/src/main/java/org/apache/camel/CamelContext.java | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/core/camel-api/src/main/java/org/apache/camel/CamelContext.java b/core/camel-api/src/main/java/org/apache/camel/CamelContext.java
index 7f8ebdc2ac0ee..dfb99f19fc75c 100644
--- a/core/camel-api/src/main/java/org/apache/camel/CamelContext.java
+++ b/core/camel-api/src/main/java/org/apache/camel/CamelContext.java
@@ -82,6 +82,8 @@
  * <p/>
  * You can use the {@link CamelContext#getCamelContextExtension()} to obtain the extension point for the
  * {@link CamelContext}. This extension point exposes internal APIs via {@link ExtendedCamelContext}.
+ *
+ * TEST: Java change — OpenRewrite SHOULD run for core/camel-api only.
  */
 public interface CamelContext extends CamelContextLifecycle, RuntimeConfiguration {