Fix clear year and month field when converting to biblatex

CHANGELOG.md

@@ -54,6 +54,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We fixed an issue where JabRef switched to discrete graphics under macOS [#5935](https://github.com/JabRef/jabref/issues/5935)
 - We fixed an issue where the Preferences entry preview will be unexpected modified leads to Value too long exception [#6198](https://github.com/JabRef/jabref/issues/6198)
 - We fixed an issue where custom jstyles for Open/LibreOffice would only be valid if a layout line for the entry type `default` was at the end of the layout section [#6303](https://github.com/JabRef/jabref/issues/6303)
+- We fixed an issue where year and month fields were not cleared when converting to biblatex [#6224](https://github.com/JabRef/jabref/issues/6224)
 
 ### Removed
 

src/main/java/org/jabref/logic/cleanup/ConvertToBiblatexCleanup.java

@@ -39,8 +39,18 @@ public List<FieldChange> cleanup(BibEntry entry) {
                 entry.clearField(StandardField.YEAR).ifPresent(changes::add);
                 entry.clearField(StandardField.MONTH).ifPresent(changes::add);
             });
+        } else {
+            // If date field is filled and is equal to year it should be removed the year and month fields
+            entry.getFieldOrAlias(StandardField.DATE).ifPresent(date -> {
+                entry.getFieldOrAlias(StandardField.YEAR).ifPresent(yearl -> {
+                    // Get the year of the date field (4 digits).
+                    if (date.substring(0, 4).equals(yearl)) {
+                        entry.clearField(StandardField.YEAR).ifPresent(changes::add);
+                        entry.clearField(StandardField.MONTH).ifPresent(changes::add);
+                    }
+                });
+            });
         }
         return changes;
     }
-
 }

src/test/java/org/jabref/logic/cleanup/ConvertToBiblatexCleanupTest.java

@@ -33,7 +33,7 @@ public void cleanupMovesYearMonthToDate() {
     }
 
     @Test
-    public void cleanupWithDateAlreadyPresentDoesNothing() {
+    public void cleanupWithDateAlreadyPresentAndDifferentFromYearDoesNothing() {
         BibEntry entry = new BibEntry();
         entry.setField(StandardField.YEAR, "2011");
         entry.setField(StandardField.MONTH, "#jan#");
@@ -46,6 +46,20 @@ public void cleanupWithDateAlreadyPresentDoesNothing() {
         assertEquals(Optional.of("2012"), entry.getField(StandardField.DATE));
     }
 
+    @Test
+    public void cleanupWithDateAlreadyPresentAndEqualsToYearRemovesYearAndMonth() {
+        BibEntry entry = new BibEntry();
+        entry.setField(StandardField.YEAR, "2011");
+        entry.setField(StandardField.MONTH, "#jan#");
+        entry.setField(StandardField.DATE, "2011");
+
+        worker.cleanup(entry);
+
+        assertEquals(Optional.empty(), entry.getField(StandardField.YEAR));
+        assertEquals(Optional.empty(), entry.getField(StandardField.MONTH));
+        assertEquals(Optional.of("2011"), entry.getField(StandardField.DATE));
+    }
+
     @Test
     public void cleanupMovesJournalToJournaltitle() {
         BibEntry entry = new BibEntry().withField(StandardField.JOURNAL, "Best of JabRef");