isNumString function

IValidator isNumString()

Validates that the String can be parsed as a num (int or double)

Implementation

IValidator isNumString() =>
    isType<String>() &
    validator(
      (value) => num.tryParse(value.trim()) != null,
      (value) => Expectation(
          message: 'a valid formatted number String', value: value, code: 'value.format_invalid', data: {'format': 'num'}),
    );