Comparison is not commutative

[vmeyet]

see the following:

Semantic::Version.new('1.0.0') == '1.0.0'
# true
'1.0.0' == Semantic::Version.new('1.0.0')
# false

IMO this should returns the same value. Surprising behaviors should be avoided at all cost (https://en.wikipedia.org/wiki/Principle_of_least_astonishment).

I know that on Numeric classes there is a special method called coerce that allow to change the comparison object without changing the base class (class of the instance on the left of the operator).

But coerce doesn't seem to exist on String.

So I'm not sure what could be the right approach here.

[leehericks]

This project doesn't seem actively maintained so I have been modernizing the code independently. For what it is worth, I will share how to fix this bug here.

# When checking str <=> ver, String will check if ver responds to :coerce
# The allows you to use <, >, <=, >= but not == unfortunately
def coerce(other_version)
  if other_version.is_a?(String)
    [ Version.new(other_version), self ]
  else
    raise TypeError, "Cannot coerce #{other_version.class} to Semantic::Version"
  end
end

# Coerce is not used for == equality checks
# I thought that when checking str == ver, String will check if ver responds to :to_str, and call ver.==(self)
# but actually causes String to NOT use coerce at all but rather it's own == with ver.to_str...so this will not work. :(