Folding Ranges implementation

internal/ls/format.go

@@ -137,6 +137,9 @@ func getRangeOfEnclosingComment(
 	precedingToken *ast.Node,
 	tokenAtPosition *ast.Node,
 ) *ast.CommentRange {
+	if tokenAtPosition == nil {
+		tokenAtPosition = astnav.GetTokenAtPosition(file, position)
+	}
 	jsdoc := ast.FindAncestor(tokenAtPosition, (*ast.Node).IsJSDoc)
 	if jsdoc != nil {
 		tokenAtPosition = jsdoc.Parent

internal/ls/utilities.go

@@ -393,7 +393,7 @@ func isInRightSideOfInternalImportEqualsDeclaration(node *ast.Node) bool {
 }
 
 func (l *LanguageService) createLspRangeFromNode(node *ast.Node, file *ast.SourceFile) *lsproto.Range {
-	return l.createLspRangeFromBounds(node.Pos(), node.End(), file)
+	return l.createLspRangeFromBounds(astnav.GetStartOfNode(node, file, false /*includeJSDoc*/), node.End(), file)
 }
 
 func (l *LanguageService) createLspRangeFromBounds(start, end int, file *ast.SourceFile) *lsproto.Range {

internal/lsp/server.go

@@ -500,6 +500,9 @@ func (s *Server) handleRequestOrNotification(ctx context.Context, req *lsproto.R
 		return s.handleDocumentSymbol(ctx, req)
 	case *lsproto.CompletionItem:
 		return s.handleCompletionItemResolve(ctx, req)
+	case *lsproto.FoldingRangeParams:
+		return s.handleFoldingRange(ctx, req)
+
 	default:
 		switch req.Method {
 		case lsproto.MethodShutdown:
@@ -584,6 +587,9 @@ func (s *Server) handleInitialize(req *lsproto.RequestMessage) {
 			DocumentSymbolProvider: &lsproto.BooleanOrDocumentSymbolOptions{
 				Boolean: ptrTo(true),
 			},
+			FoldingRangeProvider: &lsproto.BooleanOrFoldingRangeOptionsOrFoldingRangeRegistrationOptions{
+				Boolean: ptrTo(true),
+			},
 		},
 	})
 }
@@ -683,6 +689,16 @@ func (s *Server) handleSignatureHelp(ctx context.Context, req *lsproto.RequestMe
 	return nil
 }
 
+func (s *Server) handleFoldingRange(ctx context.Context, req *lsproto.RequestMessage) error {
+	params := req.Params.(*lsproto.FoldingRangeParams)
+	project := s.projectService.EnsureDefaultProjectForURI(params.TextDocument.Uri)
+	languageService, done := project.GetLanguageServiceForRequest(ctx)
+	defer done()
+	foldingRanges := languageService.ProvideFoldingRange(ctx, params.TextDocument.Uri)
+	s.sendResult(req.ID, foldingRanges)
+	return nil
+}
+
 func (s *Server) handleDefinition(ctx context.Context, req *lsproto.RequestMessage) error {
 	params := req.Params.(*lsproto.DefinitionParams)
 	project := s.projectService.EnsureDefaultProjectForURI(params.TextDocument.Uri)

internal/printer/printer.go

@@ -5044,7 +5044,7 @@ func (p *Printer) emitCommentsBeforeToken(token ast.Kind, pos int, contextNode *
 
 	if contextNode.Pos() != startPos {
 		indentLeading := flags&tefIndentLeadingComments != 0
-		needsIndent := indentLeading && p.currentSourceFile != nil && !positionsAreOnSameLine(startPos, pos, p.currentSourceFile)
+		needsIndent := indentLeading && p.currentSourceFile != nil && !PositionsAreOnSameLine(startPos, pos, p.currentSourceFile)
 		p.increaseIndentIf(needsIndent)
 		p.emitLeadingComments(startPos, false /*elided*/)
 		p.decreaseIndentIf(needsIndent)

internal/printer/utilities.go

@@ -335,23 +335,23 @@ func rangeIsOnSingleLine(r core.TextRange, sourceFile *ast.SourceFile) bool {
 }
 
 func rangeStartPositionsAreOnSameLine(range1 core.TextRange, range2 core.TextRange, sourceFile *ast.SourceFile) bool {
-	return positionsAreOnSameLine(
+	return PositionsAreOnSameLine(
 		getStartPositionOfRange(range1, sourceFile, false /*includeComments*/),
 		getStartPositionOfRange(range2, sourceFile, false /*includeComments*/),
 		sourceFile,
 	)
 }
 
 func rangeEndPositionsAreOnSameLine(range1 core.TextRange, range2 core.TextRange, sourceFile *ast.SourceFile) bool {
-	return positionsAreOnSameLine(range1.End(), range2.End(), sourceFile)
+	return PositionsAreOnSameLine(range1.End(), range2.End(), sourceFile)
 }
 
 func rangeStartIsOnSameLineAsRangeEnd(range1 core.TextRange, range2 core.TextRange, sourceFile *ast.SourceFile) bool {
-	return positionsAreOnSameLine(getStartPositionOfRange(range1, sourceFile, false /*includeComments*/), range2.End(), sourceFile)
+	return PositionsAreOnSameLine(getStartPositionOfRange(range1, sourceFile, false /*includeComments*/), range2.End(), sourceFile)
 }
 
 func rangeEndIsOnSameLineAsRangeStart(range1 core.TextRange, range2 core.TextRange, sourceFile *ast.SourceFile) bool {
-	return positionsAreOnSameLine(range1.End(), getStartPositionOfRange(range2, sourceFile, false /*includeComments*/), sourceFile)
+	return PositionsAreOnSameLine(range1.End(), getStartPositionOfRange(range2, sourceFile, false /*includeComments*/), sourceFile)
 }
 
 func getStartPositionOfRange(r core.TextRange, sourceFile *ast.SourceFile, includeComments bool) int {
@@ -361,7 +361,7 @@ func getStartPositionOfRange(r core.TextRange, sourceFile *ast.SourceFile, inclu
 	return scanner.SkipTriviaEx(sourceFile.Text(), r.Pos(), &scanner.SkipTriviaOptions{StopAtComments: includeComments})
 }
 
-func positionsAreOnSameLine(pos1 int, pos2 int, sourceFile *ast.SourceFile) bool {
+func PositionsAreOnSameLine(pos1 int, pos2 int, sourceFile *ast.SourceFile) bool {
 	return getLinesBetweenPositions(sourceFile, pos1, pos2) == 0
 }
 

internal/scanner/scanner.go

@@ -2363,6 +2363,26 @@ func GetLineAndCharacterOfPosition(sourceFile ast.SourceFileLike, pos int) (line
 	return
 }
 
+func GetLineEndOfPosition(sourceFile ast.SourceFileLike, pos int) int {
+	line, _ := GetLineAndCharacterOfPosition(sourceFile, pos)
+	lineStarts := GetLineStarts(sourceFile)
+
+	var lastCharPos int
+	if line+1 >= len(lineStarts) {
+		lastCharPos = len(sourceFile.Text())
+	} else {
+		lastCharPos = int(lineStarts[line+1] - 1)
+	}
+
+	fullText := sourceFile.Text()
+	// if the new line is "\r\n", we should return the last non-new-line-character position
+	if len(fullText) > 0 && len(fullText) != lastCharPos && fullText[lastCharPos] == '\n' && fullText[lastCharPos-1] == '\r' {
+		return lastCharPos - 1
+	} else {
+		return lastCharPos
+	}
+}
+
 func GetEndLinePosition(sourceFile *ast.SourceFile, line int) int {
 	pos := int(GetLineStarts(sourceFile)[line])
 	for {