Handle unclosed code snippets

Author: SougandhS

org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/formatter/FormatterMarkdownCommentsTests.java

@@ -768,30 +768,25 @@ class TestFakeFences {
 					""";
 		formatSource(input, expected);
 	}
-	public void testMarkdownInvalidCodeFences() throws JavaModelException {
+	public void testMarkdownUnclosedCodeFences() throws JavaModelException {
 		setComplianceLevel(CompilerOptions.VERSION_23);
-		this.formatterPrefs.comment_line_length = 25;
 		String input = """
 					/// ```
 					/// public class HelloWorld3 {
 					/// 	public static void main(String args) {
 					/// 			System.out.println("ssdd World!");
 					/// 	}
 					/// }
-					///
-					/// New 	err
 					class Mark61 {
 					}
 					""";
 		String expected = """
-					/// ``` public class
-					/// HelloWorld3 { public
-					/// static void
-					/// main(String args) {
-					/// System.out.println("ssdd
-					/// World!"); } }
-					///
-					/// New err
+					/// ```
+					/// public class HelloWorld3 {
+					/// 	public static void main(String args) {
+					/// 		System.out.println("ssdd World!");
+					/// 	}
+					/// }\s
 					class Mark61 {
 					}
 					""";

org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/CommentsPreparator.java

@@ -136,6 +136,7 @@ public class CommentsPreparator extends ASTVisitor {
 	private DefaultCodeFormatter preTagCodeFormatter;
 	private DefaultCodeFormatter snippetCodeFormatter;
 	private boolean snippetForMarkdown = false;
+	private boolean isUnclosedSnippet = false;
 
 	public CommentsPreparator(TokenManager tm, DefaultCodeFormatterOptions options, String sourceLevel) {
 		this.tm = tm;
@@ -886,6 +887,16 @@ private void handleMarkdown(TagElement node) {
 			}
 			if (shouldDisable) {
 				disableFormatting(tokenIndex, tokenIndexLast, false);
+			} else if (closingToken == null) {
+				if (tokenIndex > 1)
+					openingToken.breakBefore();
+				openingToken.breakAfter();
+				tokenIndexLast = this.ctm.findIndex(startPos + node.getLength(), ANY, true);
+				this.snippetForMarkdown = true;
+				this.isUnclosedSnippet = true;
+				formatCode(tokenIndex, tokenIndexLast - 1, true);
+				this.snippetForMarkdown = false;
+				this.isUnclosedSnippet = false;
 			}
 		}
 
@@ -1613,7 +1624,7 @@ private void addSubstituteWraps() {
 
 	private boolean formatCode(int openingIndex, int closingIndex, boolean snippetTag) {
 		int codeStartPosition = this.ctm.get(openingIndex).originalEnd + 1;
-		int codeEndPosition = this.ctm.get(closingIndex).originalStart - 1;
+		int codeEndPosition = this.isUnclosedSnippet ? this.ctm.get(closingIndex).originalStart + 1 : this.ctm.get(closingIndex).originalStart - 1;
 		StringBuilder codeBuilder = new StringBuilder(codeEndPosition - codeStartPosition + 1);
 		int[] positionMapping = new int[codeEndPosition - codeStartPosition + 1];
 		// ^ index: original source position (minus startPosition), value: position in code string
@@ -1636,11 +1647,12 @@ private boolean formatCode(int openingIndex, int closingIndex, boolean snippetTa
 		// there are too few linebreaks at the start and end
 		Token start = formattedTokens.get(0);
 		start.putLineBreaksBefore(start.getLineBreaksBefore() + 1);
-		Token end = formattedTokens.get(formattedTokens.size() - 1);
-		end.putLineBreaksAfter(end.getLineBreaksAfter() + 1);
-		// and there may be too many line breaks before closing tag
-		this.ctm.get(closingIndex).clearLineBreaksBefore();
-
+		if(!this.isUnclosedSnippet) {
+			Token end = formattedTokens.get(formattedTokens.size() - 1);
+			end.putLineBreaksAfter(end.getLineBreaksAfter() + 1);
+			// and there may be too many line breaks before closing tag
+			this.ctm.get(closingIndex).clearLineBreaksBefore();
+		}
 		List<Token> tokensToReplace = this.commentStructure.subList(openingIndex + 1, closingIndex);
 		tokensToReplace.clear();
 		tokensToReplace.addAll(formattedTokens);

org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/TextEditsBuilder.java

@@ -419,7 +419,8 @@ private ReplaceEdit getReplaceEdit(int editStart, int editEnd, String text, IReg
 			text = adaptReplaceText(text, breaksToPreserve, true, regionEnd);
 			editEnd = regionEnd;
 		}
-		return new ReplaceEdit(editStart, editEnd - editStart, text);
+		int length = editEnd - editStart < 0 ? 0 : editEnd - editStart;
+		return new ReplaceEdit(editStart, length, text);
 	}
 
 	private boolean isOnlyWhitespace(String text) {