Propagate exceptions from sync or async jobs back up the graph as err…

…backs

* Allows all exceptions to be handled in main thread
* Exception can be reraised in job.errback if required

dsltest.rb

@@ -30,5 +30,9 @@ class Download < Noodler::Job
     job.callback do
       puts "Finished everything!"
     end
+    job.errback do |e|
+      # raise e
+      puts "Job failed with exception #{e.class}, #{e.message}"
+    end
   }
 }

lib/noodler/job.rb

@@ -28,6 +28,9 @@ def run
       root.callback do
         succeed
       end
+      root.errback do |e|
+        fail e
+      end
       self
     end
 

lib/noodler/node.rb

@@ -22,6 +22,9 @@ def <<(child)
           succeed
         end
       end
+      child.errback do |e|
+        fail e
+      end
       @children << child
     end
 
@@ -39,11 +42,20 @@ def run_async(input)
       deferrable.errback do
         puts "Deferrable strategy failed"
       end
+    rescue => e
+      fail e
     end
 
     def run_sync(input)
       EM.defer \
-        lambda { @output = @strategy.call(input); },
+        lambda {
+          begin
+            @output = @strategy.call(input);
+          rescue => e
+            puts "exception caught in thread - propagating back"
+            fail e
+          end
+        },
         lambda { EM.next_tick(method(:run_children)) }
     end