Difference in error behavior for Rational()

[dazuma]

In MRI (2.7.5 and 3.1.0 tested):

Rational("")  # raises ArgumentError

In TruffleRuby 21.3.0:

Rational("")  # => (0/1)

It seems that the same applies to any non-numeric string.

[eregon]

Indeed, thanks for the report, @aardvark179 could you take a look?
It sounds like Rational() is not strict with strings for some reason (looks like we're using to_r for Strings which is not strict, seems that code comes from Rubinius).

[aardvark179]

We end up delegating Rational('') to Rational.convert('', 1), which then falls ''.to_r. That all seems entirely sensible, but ''.to_r does return 0/1 on both MRI and TruffleRuby.

I love it when two different routes to creating something return different results. :-)

[aardvark179]

This is now fixed on master (5fd59aa).