fix: improve rope_test

server/types/rope.go

@@ -102,14 +102,15 @@ func (r *Rope) OffsetFromPosition(position lsp.Position) int {
 
 	// Ensure character is within valid range
 	if position.Character >= uint32(len(line)) {
-		position.Character = uint32(len(line) - 1)
+		position.Character = uint32(len(line))
 	}
 
 	// Calculate byte offset
 	offset := 0
 	for i := 0; i < int(position.Line); i++ {
 		offset += len(lines[i]) + 1 // Add 1 for the newline character
 	}
+
 	offset += int(position.Character)
 
 	return offset

server/types/rope_test.go

@@ -83,6 +83,10 @@ func TestOffsetFromPosition(t *testing.T) {
 		if offset != expected {
 			t.Errorf("Expected offset: %d, Got offset: %d", expected, offset)
 		}
+
+		if r.text[:offset] != "Hello, World!\nThis i" {
+			t.Errorf("Expected text: %s, Got text: %s", "Hello, World!\nThis ", r.text[:offset])
+		}
 	})
 
 	t.Run("Position Exceeds Line Length", func(t *testing.T) {
@@ -91,10 +95,14 @@ func TestOffsetFromPosition(t *testing.T) {
 
 		offset := r.OffsetFromPosition(position)
 
-		expected := 28 // Maximum offset is 28 (end of text)
+		expected := 29 // Maximum offset is 29 (end of text)
 		if offset != expected {
 			t.Errorf("Expected offset: %d, Got offset: %d", expected, offset)
 		}
+
+		if r.text[:offset] != "Hello, World!\nThis is a test." {
+			t.Errorf("Expected text: %s, Got text: %s", "Hello, World!\nThis is a test.", r.text[:offset])
+		}
 	})
 
 	t.Run("Position Exceeds Line Count", func(t *testing.T) {
@@ -107,5 +115,9 @@ func TestOffsetFromPosition(t *testing.T) {
 		if offset != expected {
 			t.Errorf("Expected offset: %d, Got offset: %d", expected, offset)
 		}
+
+		if r.text[:offset] != "Hello, World!\nThis i" {
+			t.Errorf("Expected text: %s, Got text: %s", "Hello, World!\nThis i", r.text[:offset])
+		}
 	})
 }