Fixed bug in Write

Author: linkdotnet

CHANGELOG.md

@@ -6,6 +6,10 @@ All notable changes to **ValueStringBuilder** will be documented in this file. T
 
 ## [Unreleased]
 
+### Fixed
+
+- `Write` did not return the correct amount of added characters
+
 ## [0.6.0] - 2022-12-28
 
 ### Added
@@ -14,7 +18,7 @@ All notable changes to **ValueStringBuilder** will be documented in this file. T
 
 ## [0.5.3] - 2022-12-28
 
-\### Changed
+### Changed
 
 -   Smaller internal refactorings
 

stringbuilder.go

@@ -188,7 +188,7 @@ func (s *StringBuilder) Replace(oldValue string, newValue string) {
 func (s *StringBuilder) Write(p []byte) (int, error) {
 	before := s.Len()
 	s.Append(string(p))
-	delta := before - s.Len()
+	delta := s.Len() - before
 
 	return delta, nil
 }

stringbuilder_test.go

@@ -348,6 +348,14 @@ func TestWrite(t *testing.T) {
 	}
 }
 
+func TestWriteReturnsAddedAmount(t *testing.T) {
+	s := &StringBuilder{}
+
+	if got, _ := fmt.Fprintf(s, "%v", "Hello"); got != 5 {
+		t.Errorf("StringBuilder.Write() = %v, want %v", got, 5)
+	}
+}
+
 func slicesEqual(a []int, b []int) bool {
 	if len(a) != len(b) {
 		return false