changed default Promise#then behaviour without rescue callable

Author: mighe

lib/concurrent/promise.rb

@@ -12,9 +12,11 @@ class Promise
     # @see http://wiki.commonjs.org/wiki/Promises/A
     # @see http://promises-aplus.github.io/promises-spec/
     def initialize(options = {}, &block)
+      options.delete_if {|k, v| v.nil?}
+
       @parent = options.fetch(:parent) { nil }
       @on_fulfill = options.fetch(:on_fulfill) { Proc.new{ |result| result } }
-      @on_reject = options.fetch(:on_reject) { Proc.new{ |result| result } }
+      @on_reject = options.fetch(:on_reject) { Proc.new{ |reason| raise reason } }
 
       @promise_body = block || Proc.new{|result| result }
       @state = :unscheduled

spec/concurrent/promise_spec.rb

@@ -307,6 +307,12 @@ module Concurrent
         expected.should eq 20
       end
 
+      it 'uses result as fulfillment value when a promise has no block' do
+        p = Promise.new{ 20 }.then(Proc.new{}).execute
+        sleep(0.1)
+        p.value.should eq 20
+      end
+
       it 'can manage long chain' do
         root = Promise.new { 20 }
         p1 = root.then { |b| b * 3 }
@@ -345,6 +351,13 @@ module Concurrent
         p.should be_rejected
       end
 
+      it 'uses reason as rejection reason when a promise has no rescue callable' do
+        p = Promise.new{ raise ArgumentError }.then { |val| val }.execute
+        sleep(0.1)
+        p.should be_rejected
+        p.reason.should be_a ArgumentError
+      end
+
     end
 
     context 'aliases' do