[MSHADE-363] IT to check new Reproducible transformer with old plugin
diff --git a/pom.xml b/pom.xml
index 4dfbad4..b2e5a68 100644
--- a/pom.xml
+++ b/pom.xml
@@ -288,6 +288,9 @@
               </goals>
               <projectsDirectory>src/it/projects</projectsDirectory>
               <settingsFile>src/it/mrm/settings.xml</settingsFile>
+              <extraArtifacts>
+                <extraArtifact>org.apache.maven.plugins:maven-shade-plugin:${project.version}:test-jar</extraArtifact>
+              </extraArtifacts>
             </configuration>
           </plugin>
           <plugin>
diff --git a/src/it/projects/MSHADE-363_old-plugin/pom.xml b/src/it/projects/MSHADE-363_old-plugin/pom.xml
new file mode 100644
index 0000000..bf78267
--- /dev/null
+++ b/src/it/projects/MSHADE-363_old-plugin/pom.xml
@@ -0,0 +1,65 @@
+<?xml version="1.0" encoding="UTF-8"?>

+<!--

+Licensed to the Apache Software Foundation (ASF) under one

+or more contributor license agreements.  See the NOTICE file

+distributed with this work for additional information

+regarding copyright ownership.  The ASF licenses this file

+to you under the Apache License, Version 2.0 (the

+"License"); you may not use this file except in compliance

+with the License.  You may obtain a copy of the License at

+

+  http://www.apache.org/licenses/LICENSE-2.0

+

+Unless required by applicable law or agreed to in writing,

+software distributed under the License is distributed on an

+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

+KIND, either express or implied.  See the License for the

+specific language governing permissions and limitations

+under the License.

+-->

+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

+  <modelVersion>4.0.0</modelVersion>

+

+  <groupId>org.apache.maven.its.shade.pp</groupId>

+  <artifactId>mshade-363-use-custom</artifactId>

+  <version>1.0-SNAPSHOT</version>

+

+  <name>check new ReproducibleResourceTransformer API can be used with older shade plugin</name>

+  <description>if new extensions cannot be used with older shade plugin, it will add user-visible constraints...</description>

+

+  <properties>

+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

+  </properties>

+

+  <build>

+    <plugins>

+      <plugin>

+        <groupId>org.apache.maven.plugins</groupId>

+        <artifactId>maven-shade-plugin</artifactId>

+        <version>3.2.2</version><!-- last version of maven-shade-plugin without the new ReproducibleResourceTransformer interface -->

+        <dependencies>

+          <dependency><!-- tests.jar adds an extra ResourceTransformer released a few years ago, with the missing ReproducibleResourceTransformer interface -->

+            <groupId>org.apache.maven.plugins</groupId>

+            <artifactId>maven-shade-plugin</artifactId>

+            <version>@project.version@</version>

+            <classifier>tests</classifier>

+          </dependency>

+        </dependencies>

+        <executions>

+          <execution>

+            <id>use-extra-resource-transformer</id>

+            <phase>package</phase>

+            <goals>

+              <goal>shade</goal>

+            </goals>

+            <configuration>

+              <transformers><!-- use the extra transformer that implements ReproducibleResourceTransformer -->

+                <transformer implementation="org.apache.maven.plugins.shade.custom.CustomReproducibleResourceTransformer" />

+              </transformers>

+            </configuration>

+          </execution>

+        </executions>

+      </plugin>

+    </plugins>

+  </build>

+</project>

diff --git a/src/it/projects/MSHADE-363_old-plugin/src/main/resources/Message.properties b/src/it/projects/MSHADE-363_old-plugin/src/main/resources/Message.properties
new file mode 100644
index 0000000..f94d1d0
--- /dev/null
+++ b/src/it/projects/MSHADE-363_old-plugin/src/main/resources/Message.properties
@@ -0,0 +1,18 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+# 
+#   http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+one = one
diff --git a/src/test/java/org/apache/maven/plugins/shade/custom/CustomReproducibleResourceTransformer.java b/src/test/java/org/apache/maven/plugins/shade/custom/CustomReproducibleResourceTransformer.java
new file mode 100644
index 0000000..eef5744
--- /dev/null
+++ b/src/test/java/org/apache/maven/plugins/shade/custom/CustomReproducibleResourceTransformer.java
@@ -0,0 +1,78 @@
+package org.apache.maven.plugins.shade.custom;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.List;
+import java.util.jar.JarOutputStream;
+
+import org.apache.maven.plugins.shade.relocation.Relocator;
+import org.apache.maven.plugins.shade.resource.ReproducibleResourceTransformer;
+
+/**
+ * Custom ReproducibleResourceTransformer for MSHADE-363_old-plugin IT, to check that it can be run with
+ * an older maven-shade-plugin that does not contain the ReproducibleResourceTransformer interface.
+ */
+public class CustomReproducibleResourceTransformer
+    implements ReproducibleResourceTransformer
+{
+    @Override
+    public boolean canTransformResource( final String resource )
+    {
+        return true;
+    }
+
+    /**
+     * old non-reproducible RessourceTransformer API that will be used by maven-shade-plugin up to 3.2.2.
+     */
+    @Override
+    public final void processResource( final String resource, final InputStream is, final List<Relocator> relocators )
+        throws IOException
+    {
+        System.out.println( "Custom ResourceTransformer called through old API" );
+        // call new ReproducibleRessourceTransformer API using a conventional timestamp
+        processResource( resource, is, relocators, 0 );
+    }
+
+    /**
+     * new reproducible API
+     */
+    @Override
+    public void processResource( final String resource, final InputStream is, final List<Relocator> relocators,
+                                 long time )
+        throws IOException
+    {
+        System.out.println( "Custom ResourceTransformer called through new Reprodcible API" );
+    }
+
+    @Override
+    public boolean hasTransformedResource()
+    {
+        return true;
+    }
+
+    @Override
+    public void modifyOutputStream( JarOutputStream os )
+        throws IOException
+    {
+        // do-op for this test
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/org/apache/maven/plugins/shade/resource/ReproducibleResourceTransformer.java b/src/test/java/org/apache/maven/plugins/shade/resource/ReproducibleResourceTransformer.java
new file mode 100644
index 0000000..c5b7ba8
--- /dev/null
+++ b/src/test/java/org/apache/maven/plugins/shade/resource/ReproducibleResourceTransformer.java
@@ -0,0 +1,43 @@
+package org.apache.maven.plugins.shade.resource;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.maven.plugins.shade.relocation.Relocator;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.List;
+
+/**
+ * Copy of original interface necessary to MSHADE-363_old-plugin IT:
+ * CustomReproducibleResourceTransformer is built with ReproducibleResourceTransformer interface provided by
+ * recent maven-shade-plugin, but older maven-shade-plugin 3.2.2 will be used at runtime in the
+ * MSHADE-363_old-plugin IT, an older that does not provide the interface. Without the interface copy
+ * in the custom resource transformer code, this would lead to ClassNotFoundException...
+ * 
+ * @since 3.2.4
+ * @see org.apache.maven.plugins.shade.custom.CustomReproducibleResourceTransformer
+ */
+public interface ReproducibleResourceTransformer
+    extends ResourceTransformer
+{
+    void processResource( String resource, InputStream is, List<Relocator> relocators, long time )
+        throws IOException;
+}