func TestInt(t *testing.T) {
var x int
err := strconvx.Parse(&x, "1")
if err != nil {
t.Fatalf("Unexpected error: %v", err)
}
if g, e := x, int(1); g != e {
t.Errorf("Unexpected result: %v != %v", g, e)
}
}
func TestInt8OverFlow(t *testing.T) {
var x int8
err := strconvx.Parse(&x, "9000")
if err == nil {
t.Fatalf("Expected an error")
}
if g, e := err.Error(), `strconv.ParseInt: parsing "9000": value out of range`; g != e {
t.Errorf("Wrong error message: %q != %q", g, e)
}
}
func TestUintOverflow(t *testing.T) {
if !is32bit {
t.Skip("not on 32-bit architecture")
}
var x uint
err := strconvx.Parse(&x, "4294967296")
if err == nil {
t.Fatalf("Expected an error")
}
if g, e := err.Error(), `strconv.ParseInt: parsing "4294967296": value out of range`; g != e {
t.Errorf("Wrong error message: %q != %q", g, e)
}
}
// Parse fills the fields of the struct pointed to by args with input
// from the given list.
//
// Fields are handled based on their data type, for example strings
// are converted into integers when necessary.
//
// In addition to built-in conversion rules, if a field implements
// Setter, the Set method is called to do the conversion. This
// interface is compatible with flag.Value.
//
// To mark fields optional, insert an Optional marker in the struct
// after the last mandatory field.
//
// To consume any number of arguments, use a slice as the last field.
//
// Parse returns an error of type ErrMissingMandatoryArg if a mandatory
// field was not filled.
//
// Parse returns an error of type ErrTooManyArgs if there are more
// arguments than (non-slice) fields.
func Parse(args interface{}, list []string) error {
pointer := reflect.ValueOf(args).Elem()
if !pointer.CanSet() {
return errors.New("must pass a pointer to positional.Parse")
}
value := reflect.Indirect(pointer)
mandatory := true
idx := 0
for {
if idx >= value.NumField() {
break
}
if value.Type().Field(idx).Type == reflect.TypeOf(Optional{}) {
mandatory = false
idx++
continue
}
if len(list) == 0 {
if mandatory {
name := meta(value.Type().Field(idx))
return ErrMissingMandatoryArg{Name: name}
}
// only optional fields left and we ran out of args; ok
break
}
field := value.Field(idx)
switch field.Kind() {
case reflect.Slice:
if idx != value.NumField()-1 {
return errors.New("cannot have items in argument struct after a slice element")
}
// consider mandatory requirement fulfilled
mandatory = false
v := reflect.Append(field, reflect.ValueOf(list[0]))
field.Set(v)
// do NOT advance idx; slice takes rest of args
default:
v, ok := field.Addr().Interface().(Setter)
if ok {
err := v.Set(list[0])
if err != nil {
return err
}
} else {
if field.Kind() == reflect.Ptr {
// instantiate a new value, parse into it
val := reflect.New(field.Type().Elem())
field.Set(val)
field = val.Elem()
}
err := strconvx.Parse(field.Addr().Interface(), list[0])
if err != nil {
return err
}
}
idx++
}
list = list[1:]
}
if len(list) > 0 {
return ErrTooManyArgs{}
}
return nil
}
