Stop EmbeddedPostgres instance on JVM shutdown

Author: LoayTarek5

test-support/src/main/java/org/jabref/support/JournalAbbreviationTestUtil.java

@@ -1,5 +1,6 @@
 package org.jabref.support;
 
+import java.io.IOException;
 import java.sql.Connection;
 import java.sql.Statement;
 
@@ -25,6 +26,16 @@ public static synchronized DataSource getDataSource() throws Exception {
             }
             // Pre-populate once so parallel test workers never race on table creation
             JournalAbbreviationLoader.loadBuiltInRepository(dataSource);
+
+            // Stop the embedded Postgres instance when the JVM shuts down
+            final EmbeddedPostgres pgToClose = pg;
+            Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+                try {
+                    pgToClose.close();
+                } catch (IOException e) {
+                    // best effort cleanup
+                }
+            }));
         }
         return dataSource;
     }