Module: Pedant::Returns

Defined in:
lib/pedant.rb

Instance Method Summary collapse

Instance Method Details

#returns(sym, *klasses, &block) ⇒ Object 



10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
 
# File 'lib/pedant.rb', line 10

def returns(sym, *klasses, &block)
  old_method = instance_method(sym)
  self.send(:define_method, sym) do |*args|
    ret = old_method.bind(self).call(*args)
    
    # Type check
    unless klasses.empty? or klasses.any?{|klass| ret.is_a?(klass) }
      raise Pedant::TypeError, "Bad return value! Got #{ret.inspect}, " \
        "expected instance of #{klasses.inspect}."
    end
    
    # User-defined guard
    unless block.nil? or block.call(ret)
      raise Pedant::GuardError, "Did not pass user-defined guard."
    end

    ret
  end
end