public void AsInt_returns_integer_in_string(int value)
{
var testString = $"{value}";
var result = HelperExtensions.AsInt(testString);
Assert.That(result, Is.EqualTo(value));
}
public void AsInt_throws_if_invalid_string(string testString)
{
Assert.Throws <FormatException>(() => HelperExtensions.AsInt(testString));
}