Edition should not start capitalize letter

CHANGELOG.md

@@ -10,6 +10,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 ### Added
 
 - We added support for searching ShortScience for an entry through the user's browser. [#6018](https://github.com/JabRef/jabref/pull/6018)
+- We updated EditionChecker to permit edition to start with a number. [#6144](https://github.com/JabRef/jabref/issues/6144)
 - We added tooltips for most fields in the entry editor containing a short description. [#5847](https://github.com/JabRef/jabref/issues/5847)
 
 ### Changed

src/main/java/org/jabref/logic/integrity/EditionChecker.java

@@ -13,28 +13,24 @@ public class EditionChecker implements ValueChecker {
 
     private static final Predicate<String> FIRST_LETTER_CAPITALIZED = Pattern.compile("^[A-Z]").asPredicate();
     private static final Predicate<String> ONLY_NUMERALS_OR_LITERALS = Pattern.compile("^([0-9]+|[^0-9].+)$")
-            .asPredicate();
+                                                                              .asPredicate();
     private static final Predicate<String> ONLY_NUMERALS = Pattern.compile("[0-9]+").asPredicate();
     private static final String FIRST_EDITION = "1";
 
     private final BibDatabaseContext bibDatabaseContextEdition;
     private final boolean allowIntegerEdition;
 
-
     public EditionChecker(BibDatabaseContext bibDatabaseContext, boolean allowIntegerEdition) {
         this.bibDatabaseContextEdition = Objects.requireNonNull(bibDatabaseContext);
         this.allowIntegerEdition = allowIntegerEdition;
     }
 
     /**
-     * Checks, if field contains only an integer or a literal (biblatex mode)
-     * Checks, if the first letter is capitalized (BibTeX mode)
-     * biblatex package documentation:
-     * The edition of a printed publication. This must be an integer, not an ordinal.
-     * It is also possible to give the edition as a literal string, for example "Third, revised and expanded edition".
-     * Official BibTeX specification:
-     * The edition of a book-for example, "Second".
-     * This should be an ordinal, and should have the first letter capitalized.
+     * Checks, if field contains only an integer or a literal (biblatex mode) Checks, if the first letter is capitalized
+     * (BibTeX mode) biblatex package documentation: The edition of a printed publication. This must be an integer, not
+     * an ordinal. It is also possible to give the edition as a literal string, for example "Third, revised and expanded
+     * edition". Official BibTeX specification: The edition of a book-for example, "Second". This should be an ordinal,
+     * and should have the first letter capitalized.
      */
     @Override
     public Optional<String> checkValue(String value) {
@@ -53,17 +49,19 @@ public Optional<String> checkValue(String value) {
 
         //BibTeX
         if (!bibDatabaseContextEdition.isBiblatexMode()) {
-            if (!allowIntegerEdition) {
-                if (!FIRST_LETTER_CAPITALIZED.test(value.trim())) {
-                    return Optional.of(Localization.lang("should have the first letter capitalized"));
-                }
+            if (!isFirstCharDigit(value) && (!allowIntegerEdition) && !FIRST_LETTER_CAPITALIZED.test(value.trim())) {
+                return Optional.of(Localization.lang("should have the first letter capitalized"));
             } else {
                 if (!ONLY_NUMERALS.test(value.trim()) && !FIRST_LETTER_CAPITALIZED.test(value.trim())) {
                     return Optional.of(Localization.lang("should have the first letter capitalized"));
                 }
             }
         }
-
         return Optional.empty();
     }
+
+    boolean isFirstCharDigit(String input) {
+        char[] array = input.toCharArray();
+        return Character.isDigit(array[0]);
+    }
 }

src/test/java/org/jabref/logic/integrity/EditionCheckerTest.java

@@ -0,0 +1,28 @@
+package org.jabref.logic.integrity;
+
+import org.jabref.model.database.BibDatabaseContext;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class EditionCheckerTest {
+    @Test
+    void isFirstCharacterANumber() {
+        boolean allowIntegerEdition = false;
+        var bibDatabaseContextEdition = new BibDatabaseContext();
+        var editionChecker = new EditionChecker(bibDatabaseContextEdition, allowIntegerEdition);
+        var stringWithNumber = "0HelloWorld";
+        assertTrue(editionChecker.isFirstCharDigit(stringWithNumber));
+    }
+
+    @Test
+    void isFirstCharacterNotANumber() {
+        boolean allowIntegerEdition = false;
+        var bibDatabaseContextEdition = new BibDatabaseContext();
+        var editionChecker = new EditionChecker(bibDatabaseContextEdition, allowIntegerEdition);
+        var stringWithLetter = "HelloWorld";
+        assertFalse(editionChecker.isFirstCharDigit(stringWithLetter));
+    }
+}