Fix clear year and month field when converting to biblatex

CHANGELOG.md

@@ -61,6 +61,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We fixed an issue where long directory names created from patterns could create an exception. [#3915](https://github.com/JabRef/jabref/issues/3915)
 
 - We fixed an issue where sort on numeric cases was broken. [#6349](https://github.com/JabRef/jabref/issues/6349)
+- We fixed an issue where year and month fields were not cleared when converting to biblatex [#6224](https://github.com/JabRef/jabref/issues/6224)
 - We fixed an issue where an "Not on FX thread" exception occured when saving on linux [#6453](https://github.com/JabRef/jabref/issues/6453)
 - We fixed an issue where the library sort order was lost. [#6091](https://github.com/JabRef/jabref/issues/6091)
 - We fixed an issue where brackets in regular expressions were not working. [6469](https://github.com/JabRef/jabref/pull/6469)

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

@@ -3,10 +3,12 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import org.jabref.model.FieldChange;
 import org.jabref.model.cleanup.CleanupJob;
 import org.jabref.model.entry.BibEntry;
+import org.jabref.model.entry.Date;
 import org.jabref.model.entry.EntryConverter;
 import org.jabref.model.entry.field.Field;
 import org.jabref.model.entry.field.StandardField;
@@ -39,6 +41,18 @@ public List<FieldChange> cleanup(BibEntry entry) {
                 entry.clearField(StandardField.YEAR).ifPresent(changes::add);
                 entry.clearField(StandardField.MONTH).ifPresent(changes::add);
             });
+        } else {
+            // If the year from date field is filled and equal to year it should be removed the year field
+            entry.getFieldOrAlias(StandardField.DATE).ifPresent(date -> {
+                Optional<Date> newDate = Date.parse(date);
+                Optional<Date> checkDate = Date.parse(entry.getFieldOrAlias(StandardField.YEAR),
+                        entry.getFieldOrAlias(StandardField.MONTH), Optional.empty());
+
+                if (checkDate.equals(newDate)) {
+                    entry.clearField(StandardField.YEAR).ifPresent(changes::add);
+                    entry.clearField(StandardField.MONTH).ifPresent(changes::add);
+                }
+            });
         }
         return changes;
     }

src/main/java/org/jabref/model/entry/Date.java

@@ -40,6 +40,7 @@ public Date(TemporalAccessor date) {
      *  - "dd-MM-yyyy" (covers 15-1-2009)
      *  - "d.M.uuuu" (covers 15.1.2015)
      *  - "uuuu.M.d" (covers 2015.1.15)
+     *  - "MMM, uuuu" (covers Jan, 2020)
      * The code is essentially taken from http://stackoverflow.com/questions/4024544/how-to-parse-dates-in-multiple-formats-using-simpledateformat.
      */
     public static Optional<Date> parse(String dateString) {
@@ -54,7 +55,8 @@ public static Optional<Date> parse(String dateString) {
                 "MMMM d, uuuu",
                 "MMMM, uuuu",
                 "d.M.uuuu",
-                "uuuu.M.d", "uuuu");
+                "uuuu.M.d", "uuuu",
+                "MMM, uuuu");
 
         for (String formatString : formatStrings) {
             try {

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

@@ -33,17 +33,59 @@ public void cleanupMovesYearMonthToDate() {
     }
 
     @Test
-    public void cleanupWithDateAlreadyPresentDoesNothing() {
+    public void cleanupWithDateAlreadyPresentAndDifferentFromYearDoesNothing() {
         BibEntry entry = new BibEntry();
         entry.setField(StandardField.YEAR, "2011");
         entry.setField(StandardField.MONTH, "#jan#");
-        entry.setField(StandardField.DATE, "2012");
+        entry.setField(StandardField.DATE, "2012-01");
 
         worker.cleanup(entry);
 
         assertEquals(Optional.of("2011"), entry.getField(StandardField.YEAR));
         assertEquals(Optional.of("#jan#"), entry.getField(StandardField.MONTH));
-        assertEquals(Optional.of("2012"), entry.getField(StandardField.DATE));
+        assertEquals(Optional.of("2012-01"), entry.getField(StandardField.DATE));
+    }
+
+    @Test
+    public void cleanupWithDateAlreadyPresentAndDifferentFromMonthDoesNothing() {
+        BibEntry entry = new BibEntry();
+        entry.setField(StandardField.YEAR, "2011");
+        entry.setField(StandardField.MONTH, "#jan#");
+        entry.setField(StandardField.DATE, "2011-02");
+
+        worker.cleanup(entry);
+
+        assertEquals(Optional.of("2011"), entry.getField(StandardField.YEAR));
+        assertEquals(Optional.of("#jan#"), entry.getField(StandardField.MONTH));
+        assertEquals(Optional.of("2011-02"), entry.getField(StandardField.DATE));
+    }
+
+    @Test
+    public void cleanupWithEmptyDateDoesNothing() {
+        BibEntry entry = new BibEntry();
+        entry.setField(StandardField.YEAR, "");
+        entry.setField(StandardField.MONTH, "");
+        entry.setField(StandardField.DATE, "");
+
+        worker.cleanup(entry);
+
+        assertEquals(Optional.empty(), entry.getField(StandardField.YEAR));
+        assertEquals(Optional.empty(), entry.getField(StandardField.MONTH));
+        assertEquals(Optional.empty(), entry.getField(StandardField.DATE));
+    }
+
+    @Test
+    public void cleanupWithDateAlreadyPresentAndEqualsToYearAndMonth() {
+        BibEntry entry = new BibEntry();
+        entry.setField(StandardField.YEAR, "2011");
+        entry.setField(StandardField.MONTH, "#jan#");
+        entry.setField(StandardField.DATE, "2011-01");
+
+        worker.cleanup(entry);
+
+        assertEquals(Optional.empty(), entry.getField(StandardField.YEAR));
+        assertEquals(Optional.empty(), entry.getField(StandardField.MONTH));
+        assertEquals(Optional.of("2011-01"), entry.getField(StandardField.DATE));
     }
 
     @Test
@@ -55,4 +97,5 @@ public void cleanupMovesJournalToJournaltitle() {
         assertEquals(Optional.empty(), entry.getField(StandardField.JOURNAL));
         assertEquals(Optional.of("Best of JabRef"), entry.getField(StandardField.JOURNALTITLE));
     }
+
 }