add OrElse method (#17)

Co-authored-by: Luka Giorgadze <[email protected]>

gonull.go

@@ -149,6 +149,15 @@ func (n Nullable[T]) MarshalJSON() ([]byte, error) {
  return json.Marshal(n.Val)
 }
 
+// OrElse returns the underlying Val if valid otherwise returns the provided defaultVal
+func (n Nullable[T]) OrElse(defaultVal T) T {
+ if n.Valid {
+ return n.Val
+ } else {
+ return defaultVal
+ }
+}
+
 // zeroValue is a helper function that returns the zero value for the generic type T.
 // It is used to set the zero value for the Val field of the Nullable struct when the value is nil.
 func zeroValue[T any]() T {

gonull_test.go

@@ -497,6 +497,15 @@ func TestValuerAndScanner(t *testing.T) {
  }, scannerNullableUnsupported)
 }
 
+func TestNullableOrElse(t *testing.T) {
+ value := "hello"
+ nonEmpty := NewNullable(value)
+ assert.Equal(t, value, nonEmpty.OrElse("world"))
+
+ var empty Nullable[string]
+ assert.Equal(t, "world", empty.OrElse("world"))
+}
+
 type customValuer struct {
  value any
  err error