Revert chaining in functions that can return an error

Author: linkdotnet

stringbuilder.go

@@ -66,41 +66,41 @@ func (s *StringBuilder) ToString() string {
 	return string(s.data[:s.position])
 }
 
-func (s *StringBuilder) Remove(start int, length int) (*StringBuilder, error) {
+func (s *StringBuilder) Remove(start int, length int) error {
 	if start >= s.position {
-		return s, fmt.Errorf("start is after the end of the string")
+		return fmt.Errorf("start is after the end of the string")
 	}
 	if start < 0 {
-		return s, fmt.Errorf("start can't be a negative value")
+		return fmt.Errorf("start can't be a negative value")
 	}
 	if length < 0 {
-		return s, fmt.Errorf("length can't be a negative value")
+		return fmt.Errorf("length can't be a negative value")
 	}
 
 	endIndex := start + length - 1
 
 	if endIndex > s.position {
-		return s, fmt.Errorf("can't delete after the end of the string")
+		return fmt.Errorf("can't delete after the end of the string")
 	}
 
 	if length == 0 {
-		return s, nil
+		return nil
 	}
 
 	x := start + length
 	copy(s.data[start:], s.data[x:])
 	s.position -= length
 
-	return s, nil
+	return nil
 }
 
-func (s *StringBuilder) Insert(index int, text string) (*StringBuilder, error) {
+func (s *StringBuilder) Insert(index int, text string) error {
 	if index < 0 {
-		return s, fmt.Errorf("index can't be negative")
+		return fmt.Errorf("index can't be negative")
 	}
 
 	if index > s.position {
-		return s, fmt.Errorf("can't write outside the buffer")
+		return fmt.Errorf("can't write outside the buffer")
 	}
 
 	runeText := []rune(text)
@@ -112,7 +112,7 @@ func (s *StringBuilder) Insert(index int, text string) (*StringBuilder, error) {
 	s.data = append(s.data[:index], append(runeText, s.data[index:]...)...)
 	s.position = newLen
 
-	return s, nil
+	return nil
 }
 
 // Removes all characters from the current instance. This sets the internal size to 0.

stringbuilder_test.go

@@ -92,7 +92,7 @@ func TestNewFromString(t *testing.T) {
 func TestRemovePartOfString(t *testing.T) {
 	sb := NewStringBuilderFromString("Hello")
 
-	if _, err := sb.Remove(3, 2); err != nil {
+	if err := sb.Remove(3, 2); err != nil {
 		t.Errorf("Remove threw an error: %v", err)
 	}
 
@@ -104,31 +104,31 @@ func TestRemovePartOfString(t *testing.T) {
 func TestRemoveWhenStartIndexOutOfBounds(t *testing.T) {
 	sb := NewStringBuilderFromString("Hello")
 
-	if _, err := sb.Remove(100, 1); err == nil {
+	if err := sb.Remove(100, 1); err == nil {
 		t.Error("Should throw error but did not")
 	}
 }
 
 func TestRemoveWhenStartIndexNegative(t *testing.T) {
 	sb := NewStringBuilderFromString("Hello")
 
-	if _, err := sb.Remove(-1, 1); err == nil {
+	if err := sb.Remove(-1, 1); err == nil {
 		t.Error("Should throw error but did not")
 	}
 }
 
 func TestRemoveWhenLengthNegative(t *testing.T) {
 	sb := NewStringBuilderFromString("Hello")
 
-	if _, err := sb.Remove(1, -1); err == nil {
+	if err := sb.Remove(1, -1); err == nil {
 		t.Error("Should throw error but did not")
 	}
 }
 
 func TestRemoveWhenEndIndexOutOfBounds(t *testing.T) {
 	sb := NewStringBuilderFromString("Hello")
 
-	if _, err := sb.Remove(4, 4); err == nil {
+	if err := sb.Remove(4, 4); err == nil {
 		t.Error("Should throw error but did not")
 	}
 }
@@ -137,7 +137,7 @@ func TestRemoveWhenLengthZero(t *testing.T) {
 	const expected string = "Hello"
 	sb := NewStringBuilderFromString(expected)
 
-	if _, err := sb.Remove(0, 0); err != nil {
+	if err := sb.Remove(0, 0); err != nil {
 		t.Errorf("Remove threw an error: %v", err)
 	}
 
@@ -150,7 +150,7 @@ func TestRemoveInTheMiddle(t *testing.T) {
 	const expected string = "Hlo World"
 	sb := NewStringBuilderFromString("Hello World")
 
-	if _, err := sb.Remove(1, 2); err != nil {
+	if err := sb.Remove(1, 2); err != nil {
 		t.Errorf("Remove threw an error: %v", err)
 	}
 
@@ -163,7 +163,7 @@ func TestInsertAtIndex(t *testing.T) {
 	const expected string = "Hello my dear and beautiful World"
 	sb := NewStringBuilderFromString("Hello World")
 
-	if _, err := sb.Insert(5, " my dear and beautiful"); err != nil {
+	if err := sb.Insert(5, " my dear and beautiful"); err != nil {
 		t.Errorf("Insert threw an error: %v", err)
 	}
 
@@ -175,15 +175,15 @@ func TestInsertAtIndex(t *testing.T) {
 func TestInsertShouldThrowIfNegativeIndex(t *testing.T) {
 	sb := StringBuilder{}
 
-	if _, err := sb.Insert(-1, "Test"); err == nil {
+	if err := sb.Insert(-1, "Test"); err == nil {
 		t.Error("Should throw error but did not")
 	}
 }
 
 func TestInsertShouldThrowErrirIfOutOfRange(t *testing.T) {
 	sb := StringBuilder{}
 
-	if _, err := sb.Insert(1, "Test"); err == nil {
+	if err := sb.Insert(1, "Test"); err == nil {
 		t.Error("Should throw error but did not")
 	}
 }