Fix option to handle type conversion

.gitignore

@@ -34,3 +34,4 @@ go.work
 cover.out
 cover.html
 .vscode
+.idea

option.go

@@ -297,7 +297,7 @@ func (o *Option[T]) Scan(src any) error {
  }
  }
 
- return fmt.Errorf("failed to scan Option[T]")
+ return o.scanConvertValue(src)
 }
 
 // Value implements the driver Valuer interface.
@@ -306,7 +306,7 @@ func (o Option[T]) Value() (driver.Value, error) {
  return nil, nil
  }
 
- return o.value, nil
+ return driver.DefaultParameterConverter.ConvertValue(o.value)
 }
 
 // leftValue returns an error if the Option is None, otherwise nil

option_go118.go

@@ -0,0 +1,327 @@
+//go:build !go1.22
+// +build !go1.22
+
+package mo
+
+//
+// sql.Null[T] has been introduce in go1.22
+// This file is a copy of stdlib and ensure retro-compatibility.
+// See https://github.com/samber/mo/pull/49
+//
+
+import (
+ "database/sql"
+ "database/sql/driver"
+ "errors"
+ "fmt"
+ "reflect"
+ "strconv"
+ "time"
+)
+
+var errNilPtr = errors.New("destination pointer is nil")
+
+func cloneBytes(b []byte) []byte {
+ if b == nil {
+ return nil
+ }
+ c := make([]byte, len(b))
+ copy(c, b)
+ return c
+}
+
+func asString(src any) string {
+ switch v := src.(type) {
+ case string:
+ return v
+ case []byte:
+ return string(v)
+ }
+ rv := reflect.ValueOf(src)
+ switch rv.Kind() {
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ return strconv.FormatInt(rv.Int(), 10)
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+ return strconv.FormatUint(rv.Uint(), 10)
+ case reflect.Float64:
+ return strconv.FormatFloat(rv.Float(), 'g', -1, 64)
+ case reflect.Float32:
+ return strconv.FormatFloat(rv.Float(), 'g', -1, 32)
+ case reflect.Bool:
+ return strconv.FormatBool(rv.Bool())
+ }
+ return fmt.Sprintf("%v", src)
+}
+
+func asBytes(buf []byte, rv reflect.Value) (b []byte, ok bool) {
+ switch rv.Kind() {
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ return strconv.AppendInt(buf, rv.Int(), 10), true
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+ return strconv.AppendUint(buf, rv.Uint(), 10), true
+ case reflect.Float32:
+ return strconv.AppendFloat(buf, rv.Float(), 'g', -1, 32), true
+ case reflect.Float64:
+ return strconv.AppendFloat(buf, rv.Float(), 'g', -1, 64), true
+ case reflect.Bool:
+ return strconv.AppendBool(buf, rv.Bool()), true
+ case reflect.String:
+ s := rv.String()
+ return append(buf, s...), true
+ }
+ return
+}
+
+func strconvErr(err error) error {
+ if ne, ok := err.(*strconv.NumError); ok {
+ return ne.Err
+ }
+ return err
+}
+
+// convertAssignRows copies to dest the value in src, converting it if possible.
+// An error is returned if the copy would result in loss of information.
+// dest should be a pointer type. If rows is passed in, the rows will
+// be used as the parent for any cursor values converted from a
+// driver.Rows to a *Rows.
+func convertAssign(dest, src any) error {
+ // Common cases, without reflect.
+ switch s := src.(type) {
+ case string:
+ switch d := dest.(type) {
+ case *string:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = s
+ return nil
+ case *[]byte:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = []byte(s)
+ return nil
+ case *sql.RawBytes:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = append((*d)[:0], s...)
+ return nil
+ }
+ case []byte:
+ switch d := dest.(type) {
+ case *string:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = string(s)
+ return nil
+ case *any:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = cloneBytes(s)
+ return nil
+ case *[]byte:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = cloneBytes(s)
+ return nil
+ case *sql.RawBytes:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = s
+ return nil
+ }
+ case time.Time:
+ switch d := dest.(type) {
+ case *time.Time:
+ *d = s
+ return nil
+ case *string:
+ *d = s.Format(time.RFC3339Nano)
+ return nil
+ case *[]byte:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = []byte(s.Format(time.RFC3339Nano))
+ return nil
+ case *sql.RawBytes:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = s.AppendFormat((*d)[:0], time.RFC3339Nano)
+ return nil
+ }
+ case nil:
+ switch d := dest.(type) {
+ case *any:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = nil
+ return nil
+ case *[]byte:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = nil
+ return nil
+ case *sql.RawBytes:
+ if d == nil {
+ return errNilPtr
+ }
+ *d = nil
+ return nil
+ }
+ }
+
+ var sv reflect.Value
+
+ switch d := dest.(type) {
+ case *string:
+ sv = reflect.ValueOf(src)
+ switch sv.Kind() {
+ case reflect.Bool,
+ reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+ reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+ reflect.Float32, reflect.Float64:
+ *d = asString(src)
+ return nil
+ }
+ case *[]byte:
+ sv = reflect.ValueOf(src)
+ if b, ok := asBytes(nil, sv); ok {
+ *d = b
+ return nil
+ }
+ case *sql.RawBytes:
+ sv = reflect.ValueOf(src)
+ if b, ok := asBytes([]byte(*d)[:0], sv); ok {
+ *d = sql.RawBytes(b)
+ return nil
+ }
+ case *bool:
+ bv, err := driver.Bool.ConvertValue(src)
+ if err == nil {
+ *d = bv.(bool)
+ }
+ return err
+ case *any:
+ *d = src
+ return nil
+ }
+
+ if scanner, ok := dest.(sql.Scanner); ok {
+ return scanner.Scan(src)
+ }
+
+ dpv := reflect.ValueOf(dest)
+ if dpv.Kind() != reflect.Pointer {
+ return errors.New("destination not a pointer")
+ }
+ if dpv.IsNil() {
+ return errNilPtr
+ }
+
+ if !sv.IsValid() {
+ sv = reflect.ValueOf(src)
+ }
+
+ dv := reflect.Indirect(dpv)
+ if sv.IsValid() && sv.Type().AssignableTo(dv.Type()) {
+ switch b := src.(type) {
+ case []byte:
+ dv.Set(reflect.ValueOf(cloneBytes(b)))
+ default:
+ dv.Set(sv)
+ }
+ return nil
+ }
+
+ if dv.Kind() == sv.Kind() && sv.Type().ConvertibleTo(dv.Type()) {
+ dv.Set(sv.Convert(dv.Type()))
+ return nil
+ }
+
+ // The following conversions use a string value as an intermediate representation
+ // to convert between various numeric types.
+ //
+ // This also allows scanning into user defined types such as "type Int int64".
+ // For symmetry, also check for string destination types.
+ switch dv.Kind() {
+ case reflect.Pointer:
+ if src == nil {
+ dv.Set(reflect.Zero(dv.Type()))
+ return nil
+ }
+ dv.Set(reflect.New(dv.Type().Elem()))
+ return convertAssign(dv.Interface(), src)
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ if src == nil {
+ return fmt.Errorf("converting NULL to %s is unsupported", dv.Kind())
+ }
+ s := asString(src)
+ i64, err := strconv.ParseInt(s, 10, dv.Type().Bits())
+ if err != nil {
+ err = strconvErr(err)
+ return fmt.Errorf("converting driver.Value type %T (%q) to a %s: %v", src, s, dv.Kind(), err)
+ }
+ dv.SetInt(i64)
+ return nil
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+ if src == nil {
+ return fmt.Errorf("converting NULL to %s is unsupported", dv.Kind())
+ }
+ s := asString(src)
+ u64, err := strconv.ParseUint(s, 10, dv.Type().Bits())
+ if err != nil {
+ err = strconvErr(err)
+ return fmt.Errorf("converting driver.Value type %T (%q) to a %s: %v", src, s, dv.Kind(), err)
+ }
+ dv.SetUint(u64)
+ return nil
+ case reflect.Float32, reflect.Float64:
+ if src == nil {
+ return fmt.Errorf("converting NULL to %s is unsupported", dv.Kind())
+ }
+ s := asString(src)
+ f64, err := strconv.ParseFloat(s, dv.Type().Bits())
+ if err != nil {
+ err = strconvErr(err)
+ return fmt.Errorf("converting driver.Value type %T (%q) to a %s: %v", src, s, dv.Kind(), err)
+ }
+ dv.SetFloat(f64)
+ return nil
+ case reflect.String:
+ if src == nil {
+ return fmt.Errorf("converting NULL to %s is unsupported", dv.Kind())
+ }
+ switch v := src.(type) {
+ case string:
+ dv.SetString(v)
+ return nil
+ case []byte:
+ dv.SetString(string(v))
+ return nil
+ }
+ }
+
+ return fmt.Errorf("unsupported Scan, storing driver.Value type %T into type %T", src, dest)
+}
+
+func (o *Option[T]) scanConvertValue(src any) error {
+ // we try to convertAssign values that we can't directly assign because ConvertValue
+ // will return immediately for v that is already a Value, even if it is a different
+ // Value type than the one we expect here.
+ var dest T
+ if err := convertAssign(&dest, src); err == nil {
+ o.isPresent = true
+ o.value = dest
+ return nil
+ }
+ return fmt.Errorf("failed to scan Option[T]")
+}

option_go122.go

@@ -0,0 +1,22 @@
+//go:build go1.22
+// +build go1.22
+
+package mo
+
+import (
+ "database/sql"
+ "fmt"
+)
+
+func (o *Option[T]) scanConvertValue(src any) error {
+ // we try to convertAssign values that we can't directly assign because ConvertValue
+ // will return immediately for v that is already a Value, even if it is a different
+ // Value type than the one we expect here.
+ var st sql.Null[T]
+ if err := st.Scan(src); err == nil {
+ o.isPresent = true
+ o.value = st.V
+ return nil
+ }
+ return fmt.Errorf("failed to scan Option[T]")
+}