Fix VerifyException in MarkdownPositions when formatting ordered list items with right parenthesis or plus bullet markers.

Update `LIST_ITEM_START_PATTERN` from `(?:\s*)((-|\*|[0-9]+\.)\s)` to `(?:\s*)(([-+*]|[0-9]+[.)])\s)`. This allows `TokenVisitor.visitListItem` to correctly recognize ordered list markers that use a right parenthesis (`)`) as permitted by Section 5.2 of the CommonMark spec (e.g., `1) foo`), as well as bullet lists using plus (`+ foo`).

PiperOrigin-RevId: 943602624

Author: kluever

core/src/main/java/com/google/googlejavaformat/java/javadoc/MarkdownPositions.java

@@ -258,5 +258,5 @@ public String toString() {
   // The leading \s here works around what appears to be a CommonMark bug. We shouldn't ever see
   // space at the purported start of a list item?
   private static final Pattern LIST_ITEM_START_PATTERN =
-      Pattern.compile("(?:\\s*)((-|\\*|[0-9]+\\.)\\s)");
+      Pattern.compile("(?:\\s*)(([-+*]|[0-9]+[.)])\\s)");
 }

core/src/test/java/com/google/googlejavaformat/java/JavadocFormattingTest.java

@@ -18,9 +18,7 @@
 import static com.google.common.truth.Truth.assertWithMessage;
 import static com.google.common.truth.TruthJUnit.assume;
 import static java.nio.charset.StandardCharsets.UTF_8;
-import static org.junit.Assert.assertThrows;
 
-import com.google.common.base.VerifyException;
 import com.google.common.io.ByteStreams;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -2124,19 +2122,32 @@ public void markdownLongCommentOnPackageDeclaration() {
     doFormatTest(input, expected);
   }
 
-  // TODO: b/346668798 - This should not throw an exception.
-  // CommonMark allows ')' as an ordered list marker (e.g. '1) foo'), but MarkdownPositions
-  // only expects '.' in LIST_ITEM_START_PATTERN, throwing a VerifyException.
   @Test
   public void markdownOrderedListWithParenthesis() {
     assume().that(MARKDOWN_JAVADOC_SUPPORTED).isTrue();
     String input =
         """
+        /// Summary paragraph.
         /// 1) first item
         /// 2) second item
         class Test {}
         """;
-    assertThrows(VerifyException.class, () -> formatter.formatSource(input));
+    String expected = input;
+    doFormatTest(input, expected);
+  }
+
+  @Test
+  public void markdownBulletListWithPlus() {
+    assume().that(MARKDOWN_JAVADOC_SUPPORTED).isTrue();
+    String input =
+        """
+        /// Summary paragraph.
+        /// + first item
+        /// + second item
+        class Test {}
+        """;
+    String expected = input;
+    doFormatTest(input, expected);
   }
 
   // TODO: b/346668798 - Test the following Markdown constructs, and make the tests work as needed.

core/src/test/java/com/google/googlejavaformat/java/javadoc/MarkdownPositionsTest.java

@@ -15,9 +15,7 @@
 
 import static com.google.common.collect.ImmutableListMultimap.flatteningToImmutableListMultimap;
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertThrows;
 
-import com.google.common.base.VerifyException;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.googlejavaformat.java.javadoc.Token.HeaderCloseTag;
 import com.google.googlejavaformat.java.javadoc.Token.HeaderOpenTag;
@@ -67,17 +65,52 @@ public void list() {
     assertThat(map).isEqualTo(expected);
   }
 
-  // TODO: b/346668798 - This should not throw an exception.
-  // CommonMark allows ')' as an ordered list marker (e.g. '1) foo'), but MarkdownPositions
-  // only expects '.' in LIST_ITEM_START_PATTERN, throwing a VerifyException.
   @Test
   public void listWithParenthesis() {
     String text =
 """
 1) foo
 2) bar
 """;
-    assertThrows(VerifyException.class, () -> MarkdownPositions.parse(text));
+    var positions = MarkdownPositions.parse(text);
+    ImmutableListMultimap<Integer, Token> map = positionToToken(positions, text);
+    int firstItem = text.indexOf('1');
+    int secondItem = text.indexOf('2');
+    int end = text.length() - 1;
+    ImmutableListMultimap<Integer, Token> expected =
+        ImmutableListMultimap.<Integer, Token>builder()
+            .put(firstItem, new ListOpenTag(""))
+            .put(firstItem, new ListItemOpenTag("1) "))
+            .put(secondItem - 1, new ListItemCloseTag(""))
+            .put(secondItem, new ListItemOpenTag("2) "))
+            .put(end, new ListItemCloseTag(""))
+            .put(end, new ListCloseTag(""))
+            .build();
+    assertThat(map).isEqualTo(expected);
+  }
+
+  @Test
+  public void listWithPlus() {
+    String text =
+"""
++ foo
++ bar
+""";
+    var positions = MarkdownPositions.parse(text);
+    ImmutableListMultimap<Integer, Token> map = positionToToken(positions, text);
+    int firstItem = text.indexOf('+');
+    int secondItem = text.lastIndexOf('+');
+    int end = text.length() - 1;
+    ImmutableListMultimap<Integer, Token> expected =
+        ImmutableListMultimap.<Integer, Token>builder()
+            .put(firstItem, new ListOpenTag(""))
+            .put(firstItem, new ListItemOpenTag("+ "))
+            .put(secondItem - 1, new ListItemCloseTag(""))
+            .put(secondItem, new ListItemOpenTag("+ "))
+            .put(end, new ListItemCloseTag(""))
+            .put(end, new ListCloseTag(""))
+            .build();
+    assertThat(map).isEqualTo(expected);
   }
 
   @Test