Add a new parseJabRefComment with unit test

src/main/java/org/jabref/logic/importer/fileformat/BibtexParser.java

@@ -58,6 +58,8 @@
 import com.dd.plist.BinaryPropertyListParser;
 import com.dd.plist.NSDictionary;
 import com.dd.plist.NSString;
+import com.google.gson.Gson;
+import com.google.gson.JsonObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
@@ -354,8 +356,8 @@ private void parseJabRefComment(Map<String, String> meta) {
         // We remove all line breaks in the metadata
         // These have been inserted to prevent too long lines when the file was saved, and are not part of the data.
         String comment = buffer.toString().replaceAll("[\\x0d\\x0a]", "");
-        if (comment.substring(0, Math.min(comment.length(), MetaData.META_FLAG.length())).equals(MetaData.META_FLAG)) {
-            if (comment.startsWith(MetaData.META_FLAG)) {
+
+        if (comment.startsWith(MetaData.META_FLAG)) {
                 String rest = comment.substring(MetaData.META_FLAG.length());
 
                 int pos = rest.indexOf(':');
@@ -366,9 +368,7 @@ private void parseJabRefComment(Map<String, String> meta) {
                     // meta comments are always re-written by JabRef and not stored in the file
                     dumpTextReadSoFarToString();
                 }
-            }
-        } else if (comment.substring(0, Math.min(comment.length(), MetaData.ENTRYTYPE_FLAG.length()))
-                          .equals(MetaData.ENTRYTYPE_FLAG)) {
+        } else if (comment.startsWith(MetaData.ENTRYTYPE_FLAG)) {
             // A custom entry type can also be stored in a
             // "@comment"
             Optional<BibEntryType> typ = MetaDataParser.parseCustomEntryType(comment);
@@ -386,9 +386,17 @@ private void parseJabRefComment(Map<String, String> meta) {
             } catch (ParseException ex) {
                 parserResult.addException(ex);
             }
+        } else if (comment.startsWith(MetaData.META_FLAG_VERSION_010)) {
+            parseCommentToJson(comment);
         }
     }
 
+    private Optional<JsonObject> parseCommentToJson(String comment) {
+        String content = comment.substring(comment.indexOf(MetaData.META_FLAG_VERSION_010) + MetaData.META_FLAG_VERSION_010.length());
+        Gson gson = new Gson();
+        return Optional.ofNullable(gson.fromJson(content, JsonObject.class));
+    }
+
     /**
      * Adds BibDesk group entries to the JabRef database
      */

src/main/java/org/jabref/logic/importer/util/MetaDataParser.java

@@ -4,6 +4,7 @@
 import java.io.Reader;
 import java.io.StringReader;
 import java.nio.file.Path;
+import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashMap;
@@ -35,6 +36,8 @@
 import org.jabref.model.strings.StringUtil;
 import org.jabref.model.util.FileUpdateMonitor;
 
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -97,6 +100,81 @@ public MetaData parse(Map<String, String> data, Character keywordSeparator) thro
         return parse(new MetaData(), data, keywordSeparator);
     }
 
+    /**
+     * Parses the given data JsonObject and returns a new resulting {@link MetaData} instance,
+     * we will use it in v6.x metadata (JSON) parse.
+     */
+    public MetaData parse(JsonObject data, Character keywordSeparator) throws ParseException {
+        return parse(new MetaData(), data, keywordSeparator);
+    }
+
+    public MetaData parse(MetaData metaData, JsonObject data, Character keywordSeparator) throws ParseException {
+        CitationKeyPattern defaultCiteKeyPattern = CitationKeyPattern.NULL_CITATION_KEY_PATTERN;
+        Map<EntryType, CitationKeyPattern> nonDefaultCiteKeyPatterns = new HashMap<>();
+
+        // process groups (GROUPSTREE and GROUPSTREE_LEGACY) at the very end (otherwise it can happen that not all dependent data are set)
+        List<Map.Entry<String, String>> entryList = new ArrayList<>();
+        for (Map.Entry<String, JsonElement> entry : data.entrySet()) {
+            // Add each entry to the list, converting JsonElement to String
+            entryList.add(new AbstractMap.SimpleEntry<>(entry.getKey(), entry.getValue().getAsString()));
+        }
+
+        entryList.sort(groupsLast());
+
+        for (Map.Entry<String, String> entry : entryList) {
+            List<String> values = getAsList(entry.getValue());
+
+            if (entry.getKey().startsWith(MetaData.PREFIX_KEYPATTERN)) {
+                EntryType entryType = EntryTypeFactory.parse(entry.getKey().substring(MetaData.PREFIX_KEYPATTERN.length()));
+                nonDefaultCiteKeyPatterns.put(entryType, new CitationKeyPattern(getSingleItem(values)));
+            } else if (entry.getKey().startsWith(MetaData.SELECTOR_META_PREFIX)) {
+                // edge case, it might be one special field e.g. article from biblatex-apa, but we can't distinguish this from any other field and rather prefer to handle it as UnknownField
+                metaData.addContentSelector(ContentSelectors.parse(FieldFactory.parseField(entry.getKey().substring(MetaData.SELECTOR_META_PREFIX.length())), StringUtil.unquote(entry.getValue(), MetaData.ESCAPE_CHARACTER)));
+            } else if (entry.getKey().equals(MetaData.FILE_DIRECTORY)) {
+                metaData.setLibrarySpecificFileDirectory(parseDirectory(entry.getValue()));
+            } else if (entry.getKey().startsWith(MetaData.FILE_DIRECTORY + '-')) {
+                // The user name starts directly after FILE_DIRECTORY + '-'
+                String user = entry.getKey().substring(MetaData.FILE_DIRECTORY.length() + 1);
+                metaData.setUserFileDirectory(user, parseDirectory(entry.getValue()));
+            } else if (entry.getKey().startsWith(MetaData.FILE_DIRECTORY_LATEX)) {
+                // The user name starts directly after FILE_DIRECTORY_LATEX + '-'
+                String user = entry.getKey().substring(MetaData.FILE_DIRECTORY_LATEX.length() + 1);
+                Path path = Path.of(parseDirectory(entry.getValue())).normalize();
+                metaData.setLatexFileDirectory(user, path);
+            } else if (entry.getKey().equals(MetaData.SAVE_ACTIONS)) {
+                metaData.setSaveActions(fieldFormatterCleanupsParse(values));
+            } else if (entry.getKey().equals(MetaData.DATABASE_TYPE)) {
+                metaData.setMode(BibDatabaseMode.parse(getSingleItem(values)));
+            } else if (entry.getKey().equals(MetaData.KEYPATTERNDEFAULT)) {
+                defaultCiteKeyPattern = new CitationKeyPattern(getSingleItem(values));
+            } else if (entry.getKey().equals(MetaData.PROTECTED_FLAG_META)) {
+                if (Boolean.parseBoolean(getSingleItem(values))) {
+                    metaData.markAsProtected();
+                } else {
+                    metaData.markAsNotProtected();
+                }
+            } else if (entry.getKey().equals(MetaData.SAVE_ORDER_CONFIG)) {
+                metaData.setSaveOrder(SaveOrder.parse(values));
+            } else if (entry.getKey().equals(MetaData.GROUPSTREE) || entry.getKey().equals(MetaData.GROUPSTREE_LEGACY)) {
+                metaData.setGroups(GroupsParser.importGroups(values, keywordSeparator, fileMonitor, metaData));
+            } else if (entry.getKey().equals(MetaData.GROUPS_SEARCH_SYNTAX_VERSION)) {
+                Version version = Version.parse(getSingleItem(values));
+                metaData.setGroupSearchSyntaxVersion(version);
+            } else if (entry.getKey().equals(MetaData.VERSION_DB_STRUCT)) {
+                metaData.setVersionDBStructure(getSingleItem(values));
+            } else {
+                // Keep meta data items that we do not know in the file
+                metaData.putUnknownMetaDataItem(entry.getKey(), values);
+            }
+        }
+
+        if (!defaultCiteKeyPattern.equals(CitationKeyPattern.NULL_CITATION_KEY_PATTERN) || !nonDefaultCiteKeyPatterns.isEmpty()) {
+            metaData.setCiteKeyPattern(defaultCiteKeyPattern, nonDefaultCiteKeyPatterns);
+        }
+
+        return metaData;
+    }
+
     /**
      * Parses the data map and changes the given {@link MetaData} instance respectively.
      *

src/main/java/org/jabref/model/metadata/MetaData.java

@@ -31,13 +31,12 @@
 import com.google.common.eventbus.EventBus;
 import com.tobiasdiez.easybind.optional.OptionalBinding;
 import com.tobiasdiez.easybind.optional.OptionalWrapper;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @AllowedToUseLogic("because it needs access to citation pattern and cleanups")
 public class MetaData {
 
     public static final String META_FLAG = "jabref-meta: ";
+    public static final String META_FLAG_VERSION_010 = "jabref-meta-0.1.0";
     public static final String ENTRYTYPE_FLAG = "jabref-entrytype: ";
     public static final String SAVE_ORDER_CONFIG = "saveOrderConfig"; // ToDo: Rename in next major version to saveOrder, adapt testbibs
     public static final String SAVE_ACTIONS = "saveActions";
@@ -58,8 +57,6 @@ public class MetaData {
     public static final char SEPARATOR_CHARACTER = ';';
     public static final String SEPARATOR_STRING = String.valueOf(SEPARATOR_CHARACTER);
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(MetaData.class);
-
     private final EventBus eventBus = new EventBus();
     private final Map<EntryType, String> citeKeyPatterns = new HashMap<>(); // <BibType, Pattern>
     private final Map<String, String> userFileDirectory = new HashMap<>(); // <User, FilePath>

src/test/java/org/jabref/logic/importer/fileformat/BibtexParserTest.java

@@ -55,6 +55,7 @@
 import org.jabref.model.groups.RegexKeywordGroup;
 import org.jabref.model.groups.TexGroup;
 import org.jabref.model.groups.WordKeywordGroup;
+import org.jabref.model.metadata.MetaData;
 import org.jabref.model.metadata.SaveOrder;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -2238,4 +2239,26 @@ void parseInvalidBibDeskFilesResultsInWarnings() throws IOException {
 
         assertEquals(List.of(firstEntry, secondEntry), result.getDatabase().getEntries());
     }
+
+    @Test
+    void parseJabRefSingleJsonComment() throws IOException {
+        String entries =
+        """
+            @Comment{jabref-meta-0.1.0
+                {
+                    "saveActions" :
+                    {
+                        "state": true,
+                        "date": ["normalize_date", "action2"],
+                        "pages" : ["normalize_page_numbers"],
+                        "month" : ["normalize_month"]
+                    }
+                }
+            }
+        """;
+        ParserResult result = parser.parse(new StringReader(entries));
+        MetaData expectedMetaData = new MetaData();
+        expectedMetaData.putUnknownMetaDataItem("jabref-meta-0.1.0", List.of("{\"saveActions\":{\"state\":true,\"date\":[\"normalize_date\",\"action2\"],\"pages\":[\"normalize_page_numbers\"],\"month\":[\"normalize_month\"]}}"));
+        assertEquals(expectedMetaData, result.getMetaData());
+    }
 }