MultipleOf 1/100 validation: it seems that MultipleOf validation always fail for price values about ogen

[nick-dd]

I understand that this is due floating-point representation discreteness.
val := new(big.Rat).SetFloat64(0.01) gives huge numbers in a/b (namely, 5764607523034235/576460752303423488), and not exactly 1/100, as it has for multipleOf value.

It seems, the difference is that multipleOf is initiated with SetString(), while val - with SetFloat64().

As a workaround I'd use a way to bypass response validation if it were possible.

[nick-dd]

This is an example of the validation code it generated for the total field:

	if err := func() error {
		if value, ok := s.Total.Get(); ok {
			if err := func() error {
				if err := (validate.Float{
					MinSet:        false,
					Min:           0,
					MaxSet:        false,
					Max:           0,
					MinExclusive:  false,
					MaxExclusive:  false,
					MultipleOfSet: true,
					MultipleOf:    ratMap["1/100"],
				}).Validate(float64(value)); err != nil {
					return errors.Wrap(err, "float")
				}
				return nil
			}(); err != nil {
				return err
			}
		}
		return nil
	}(); err != nil {
		failures = append(failures, validate.FieldError{
			Name:  "total",
			Error: err,
		})
	}

And this is what in the ratMap:

var ratMap = map[string]*big.Rat{
	"1/10": func() *big.Rat {
		r, ok := new(big.Rat).SetString("1/10")
		if !ok {
			panic(fmt.Sprintf("rat %q: can't parse", "1/10"))
		}
		return r
	}(),
	"1/100": func() *big.Rat {
		r, ok := new(big.Rat).SetString("1/100")
		if !ok {
			panic(fmt.Sprintf("rat %q: can't parse", "1/100"))
		}
		return r
	}(),
}