Add module descriptor

pom.xml

@@ -190,6 +190,35 @@
   </build>
 
   <profiles>
+    <profile>
+      <id>multi-release</id>
+      <activation>
+        <jdk>[9,)</jdk>
+      </activation>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-compiler-plugin</artifactId>
+            <executions>
+              <execution>
+                <id>java-9</id>
+                <goals>
+                  <goal>compile</goal>
+                </goals>
+                <configuration>
+                  <compileSourceRoots>
+                    <compileSourceRoot>${project.basedir}/src/main/java9</compileSourceRoot>
+                  </compileSourceRoots>
+                  <multiReleaseOutput>true</multiReleaseOutput>
+                  <release>9</release>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
     <profile>
       <id>spotless</id>
       <activation>

src/main/java9/module-info.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright © 2024 Stefano Cordio ([email protected])
+ *
+ * Licensed 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.
+ */
+
+/**
+ * JUnit Jupiter {@link org.junit.jupiter.api.io.TempDir} extension based on {@link
+ * com.google.common.jimfs.Jimfs}.
+ */
+@SuppressWarnings("requires-transitive-automatic")
+module jimfs.junit.jupiter {
+    requires transitive com.google.common.jimfs;
+    requires org.junit.jupiter.api;
+
+    exports io.github.scordio.jimfs.junit.jupiter;
+}