Errors

class CWE::Error < Exception
end

class CWE::ParseError < CWE::Error
end

class CWE::NotFoundError < CWE::Error
end

When each is raised

Handling

begin
  CWE.find!(user_input)
rescue CWE::ParseError
  # input wasn't a recognizable CWE id
rescue CWE::NotFoundError
  # id parsed but isn't in the catalog
end

Or use the non-raising variants:

case CWE.find(user_input)
when CWE::Weakness then # match
else                    # nil
end

See also

• Lookups — when to use raising vs non-raising
• CWE module