add some comments for further debugging hints

call clear in setup to ensure empty tables and no leftovers from failures

src/test/java/org/jabref/logic/shared/DBMSSynchronizerTest.java

@@ -53,7 +53,8 @@ private static Stream<Object[]> getTestingDatabaseSystems() throws InvalidDBMSCo
     }
 
     public void setUp(DBMSConnection dbmsConnection) throws Exception {
-
+        clear(dbmsConnection);
+
         bibDatabase = new BibDatabase();
         BibDatabaseContext context = new BibDatabaseContext(bibDatabase);
         dbmsSynchronizer = new DBMSSynchronizer(context, ',', pattern, new DummyFileUpdateMonitor());
@@ -94,15 +95,17 @@ public void testFieldChangedEventListener(DBMSType dbmsType, DBMSConnection dbms
         BibEntry expectedEntry = getBibEntryExample(1);
         expectedEntry.registerListener(dbmsSynchronizer);
 
-        bibDatabase.insertEntry(expectedEntry);
+        bibDatabase.insertEntry(expectedEntry); 
         expectedEntry.setField(StandardField.AUTHOR, "Brad L and Gilson");
+
+        //problem is that we somehow now have an empty entry with no fields maybe due to the all entries event?
         expectedEntry.setField(StandardField.TITLE, "The micro multiplexer", EntryEventSource.SHARED);
 
         List<BibEntry> actualEntries = dbmsProcessor.getSharedEntries();
         assertEquals(1, actualEntries.size());
         assertEquals(expectedEntry.getField(StandardField.AUTHOR), actualEntries.get(0).getField(StandardField.AUTHOR));
         assertEquals("The nano processor1", actualEntries.get(0).getField(StandardField.TITLE).get());
-
+ //somehow the field stable is not filled
         clear(dbmsConnection);
     }
 
@@ -137,12 +140,8 @@ public void testEntryRemovedEventListener(DBMSType dbmsType, DBMSConnection dbms
     @ParameterizedTest
     @MethodSource("getTestingDatabaseSystems")
     public void testMetaDataChangedEventListener(DBMSType dbmsType, DBMSConnection dbmsConnection, DBMSProcessor dbmsProcessor) throws Exception {
-
-        bibDatabase = new BibDatabase();
-        BibDatabaseContext context = new BibDatabaseContext(bibDatabase);
-        dbmsSynchronizer = new DBMSSynchronizer(context, ',', pattern, new DummyFileUpdateMonitor());
-        dbmsSynchronizer.openSharedDatabase(dbmsConnection);
-
+
+        setUp(dbmsConnection);
         MetaData testMetaData = new MetaData();
         testMetaData.registerListener(dbmsSynchronizer);
         dbmsSynchronizer.setMetaData(testMetaData);
@@ -199,7 +198,6 @@ public void testSynchronizeLocalDatabaseWithEntryRemoval(DBMSType dbmsType, DBMS
     @ParameterizedTest
     @MethodSource("getTestingDatabaseSystems")
     public void testSynchronizeLocalDatabaseWithEntryUpdate(DBMSType dbmsType, DBMSConnection dbmsConnection, DBMSProcessor dbmsProcessor) throws Exception {
-
         setUp(dbmsConnection);
 
         BibEntry bibEntry = getBibEntryExample(1);