Fixed #15: relax character index on last line

Author: spoenemann

Diff for: handler/handler.go

@@ -20,11 +20,13 @@ import (
 
 var globalCliPath string
 var enableLogging bool
+var asyncProcessing bool
 
 // Setup initializes global variables.
-func Setup(cliPath string, _enableLogging bool) {
+func Setup(cliPath string, _enableLogging bool, _asyncProcessing bool) {
 	globalCliPath = cliPath
 	enableLogging = _enableLogging
+	asyncProcessing = _asyncProcessing
 }
 
 // CLangdStarter starts clangd and returns its stdin/out/err
@@ -44,7 +46,10 @@ func NewInoHandler(stdin io.ReadCloser, stdout io.WriteCloser, logStreams *Strea
 	}
 	handler.startClangd()
 	stdStream := jsonrpc2.NewBufferedStream(logStreams.AttachStdInOut(stdin, stdout), jsonrpc2.VSCodeObjectCodec{})
-	stdHandler := jsonrpc2.AsyncHandler(jsonrpc2.HandlerWithError(handler.FromStdio))
+	var stdHandler jsonrpc2.Handler = jsonrpc2.HandlerWithError(handler.FromStdio)
+	if asyncProcessing {
+		stdHandler = jsonrpc2.AsyncHandler(stdHandler)
+	}
 	handler.StdioConn = jsonrpc2.NewConn(context.Background(), stdStream, stdHandler)
 	if enableLogging {
 		log.Println("Initial board configuration:", board)
@@ -633,7 +638,7 @@ func (handler *InoHandler) cpp2inoCompletionList(list *lsp.CompletionList, uri l
 	if data, ok := handler.data[uri]; ok {
 		newItems := make([]lsp.CompletionItem, 0, len(list.Items))
 		for _, item := range list.Items {
-			if (!strings.HasPrefix(item.InsertText, "_")) {
+			if !strings.HasPrefix(item.InsertText, "_") {
 				if item.TextEdit != nil {
 					r := &item.TextEdit.Range
 					r.Start.Line = data.sourceLineMap[r.Start.Line]
@@ -642,7 +647,7 @@ func (handler *InoHandler) cpp2inoCompletionList(list *lsp.CompletionList, uri l
 				newItems = append(newItems, item)
 			}
 		}
-		list.Items = newItems;
+		list.Items = newItems
 	}
 }
 

Diff for: handler/sourcemap.go

@@ -116,12 +116,13 @@ func copyMappings(sourceLineMap, targetLineMap, newMappings map[int]int) {
 
 // OutOfRangeError returned if one attempts to access text out of its range
 type OutOfRangeError struct {
-	Max int
-	Req lsp.Position
+	Type string
+	Max  int
+	Req  int
 }
 
 func (oor OutOfRangeError) Error() string {
-	return fmt.Sprintf("text access out of range: max=%d requested=%d", oor.Max, oor.Req)
+	return fmt.Sprintf("%s access out of range: max=%d requested=%d", oor.Type, oor.Max, oor.Req)
 }
 
 func applyTextChange(text string, rang lsp.Range, insertText string) (res string, err error) {
@@ -139,37 +140,41 @@ func applyTextChange(text string, rang lsp.Range, insertText string) (res string
 
 // getOffset computes the offset in the text expressed by the lsp.Position.
 // Returns OutOfRangeError if the position is out of range.
-func getOffset(text string, pos lsp.Position) (off int, err error) {
-	// find line
-	lineOffset := getLineOffset(text, pos.Line)
-	if lineOffset < 0 {
-		return -1, OutOfRangeError{len(text), pos}
+func getOffset(text string, pos lsp.Position) (int, error) {
+	// Find line
+	lineOffset, err := getLineOffset(text, pos.Line)
+	if err != nil {
+		return -1, err
+	}
+	character := pos.Character
+	if character == 0 {
+		return lineOffset, nil
 	}
-	off = lineOffset
 
-	// walk towards the character
-	var charFound bool
-	for offset, c := range text[off:] {
+	// Find the character and return its offset within the text
+	var count = len(text[lineOffset:])
+	for offset, c := range text[lineOffset:] {
+		if character == offset {
+			// We've found the character
+			return lineOffset + offset, nil
+		}
 		if c == '\n' {
 			// We've reached the end of line. LSP spec says we should default back to the line length.
 			// See https://microsoft.github.io/language-server-protocol/specifications/specification-3-14/#position
-			off += offset
-			charFound = true
-			break
-		}
-
-		// we've fond the character
-		if offset == pos.Character {
-			off += offset
-			charFound = true
+			if character > offset {
+				return lineOffset + offset, nil
+			}
+			count = offset
 			break
 		}
 	}
-	if !charFound {
-		return -1, OutOfRangeError{Max: len(text), Req: pos}
+	if character > 0 {
+		// We've reached the end of the last line. Default to the text length (see above).
+		return len(text), nil
 	}
 
-	return off, nil
+	// We haven't found the character in the text (character index was negative)
+	return -1, OutOfRangeError{"Character", count, character}
 }
 
 // getLineOffset finds the offset/position of the beginning of a line within the text.
@@ -178,27 +183,22 @@ func getOffset(text string, pos lsp.Position) (off int, err error) {
 //    getLineOffset(text, 0) == 0
 //    getLineOffset(text, 1) == 4
 //    getLineOffset(text, 2) == 11
-func getLineOffset(text string, line int) int {
-	if line < 0 {
-		return -1
-	}
+func getLineOffset(text string, line int) (int, error) {
 	if line == 0 {
-		return 0
+		return 0, nil
 	}
 
-	// find the line and return its offset within the text
+	// Find the line and return its offset within the text
 	var count int
 	for offset, c := range text {
-		if c != '\n' {
-			continue
-		}
-
-		count++
-		if count == line {
-			return offset + 1
+		if c == '\n' {
+			count++
+			if count == line {
+				return offset + 1, nil
+			}
 		}
 	}
 
-	// we didn't find the line in the text
-	return -1
+	// We haven't found the line in the text
+	return -1, OutOfRangeError{"Line", count, line}
 }

Diff for: handler/sourcemap_test.go

@@ -122,7 +122,6 @@ func TestApplyTextChange(t *testing.T) {
 		{
 			"foo\nbar\nbaz\n!",
 			lsp.Range{
-				// out of range start offset
 				Start: lsp.Position{Line: 0, Character: 100},
 				End:   lsp.Position{Line: 2, Character: 0},
 			},
@@ -139,18 +138,18 @@ func TestApplyTextChange(t *testing.T) {
 			},
 			"i",
 			"",
-			OutOfRangeError{13, lsp.Position{Line: 20, Character: 0}},
+			OutOfRangeError{"Line", 3, 20},
 		},
 		{
 			"foo\nbar\nbaz\n!",
 			lsp.Range{
-				// out of range start offset
+				// out of range end offset
 				Start: lsp.Position{Line: 0, Character: 0},
 				End:   lsp.Position{Line: 20, Character: 0},
 			},
 			"i",
 			"",
-			OutOfRangeError{13, lsp.Position{Line: 20, Character: 0}},
+			OutOfRangeError{"Line", 3, 20},
 		},
 	}
 
@@ -183,8 +182,10 @@ func TestGetOffset(t *testing.T) {
 		{"foo\nfoobar\nbaz", 1, 3, 7, nil},
 		{"foo\nba\nr\nbaz\n!", 3, 0, 9, nil},
 		{"foo\nba\nr\nbaz\n!", 1, 10, 6, nil},
-		{"foo\nba\nr\nbaz\n!", -1, 0, -1, OutOfRangeError{14, lsp.Position{Line: -1, Character: 0}}},
-		{"foo\nba\nr\nbaz\n!", 4, 20, -1, OutOfRangeError{14, lsp.Position{Line: 4, Character: 20}}},
+		{"foo\nba\nr\nbaz\n!", -1, 0, -1, OutOfRangeError{"Line", 4, -1}},
+		{"foo\nba\nr\nbaz\n!", 1, -1, -1, OutOfRangeError{"Character", 2, -1}},
+		{"foo\nba\nr\nbaz\n!", 4, 20, 14, nil},
+		{"foo\nba\nr\nbaz!\n", 4, 0, 14, nil},
 	}
 
 	for _, test := range tests {
@@ -203,26 +204,30 @@ func TestGetOffset(t *testing.T) {
 
 func TestGetLineOffset(t *testing.T) {
 	tests := []struct {
-		Text   string
-		Line   int
-		Offset int
+		Text string
+		Line int
+		Exp  int
+		Err  error
 	}{
-		{"foo\nfoobar\nbaz", 0, 0},
-		{"foo\nfoobar\nbaz", 1, 4},
-		{"foo\nfoobar\nbaz", 2, 11},
-		{"foo\nfoobar\nbaz", 3, -1},
-		{"foo\nba\nr\nbaz\n!", 3, 9},
-		{"foo\nba\nr\nbaz\n!", -1, -1},
-		{"foo\nba\nr\nbaz\n!", 20, -1},
+		{"foo\nfoobar\nbaz", 0, 0, nil},
+		{"foo\nfoobar\nbaz", 1, 4, nil},
+		{"foo\nfoobar\nbaz", 2, 11, nil},
+		{"foo\nfoobar\nbaz", 3, -1, OutOfRangeError{"Line", 2, 3}},
+		{"foo\nba\nr\nbaz\n!", 3, 9, nil},
+		{"foo\nba\nr\nbaz\n!", -1, -1, OutOfRangeError{"Line", 4, -1}},
+		{"foo\nba\nr\nbaz\n!", 20, -1, OutOfRangeError{"Line", 4, 20}},
 	}
 
 	for _, test := range tests {
 		st := strings.Replace(test.Text, "\n", "\\n", -1)
 
-		t.Logf("getLineOffset(\"%s\", %d) == %d", st, test.Line, test.Offset)
-		act := getLineOffset(test.Text, test.Line)
-		if act != test.Offset {
-			t.Errorf("getLineOffset(\"%s\", %d) != %d, got %d instead", st, test.Line, test.Offset, act)
+		t.Logf("getLineOffset(\"%s\", %d) == %d", st, test.Line, test.Exp)
+		act, err := getLineOffset(test.Text, test.Line)
+		if act != test.Exp {
+			t.Errorf("getLineOffset(\"%s\", %d) != %d, got %d instead", st, test.Line, test.Exp, act)
+		}
+		if err != test.Err {
+			t.Errorf("getLineOffset(\"%s\", %d) error != %v, got %v instead", st, test.Line, test.Err, err)
 		}
 	}
 }

Diff for: main.go

@@ -42,7 +42,7 @@ func main() {
 		log.SetOutput(os.Stderr)
 	}
 
-	handler.Setup(cliPath, enableLogging)
+	handler.Setup(cliPath, enableLogging, true)
 	initialBoard := handler.Board{Fqbn: initialFqbn, Name: initialBoardName}
 	inoHandler := handler.NewInoHandler(os.Stdin, os.Stdout, logStreams, startClangd, initialBoard)
 	defer inoHandler.StopClangd()