when_committed! will run immediately if not in a transaction

If you call `when_committed` outside of a transaction,
and never save the model, the block will never run.
This may be exactly what you want, since the block
might depend on changes to the model.

`when_committed!` is useful in scenarios where you
don't know if the code will be called as part of a
transaction or other model change. If it happens
as part of transaction, wait until it is committed.

Author: joshuaflanagan

lib/when_committed.rb

@@ -11,6 +11,14 @@ def when_committed(&block)
       when_committed_callbacks << block
     end
 
+    def when_committed!(&block)
+      if self.connection.open_transactions > 0
+        when_committed(&block)
+      else
+        block.call
+      end
+    end
+
     private
 
     def when_committed_callbacks

spec/when_committed_spec.rb

@@ -21,6 +21,33 @@
     model.should respond_to(:when_committed)
   end
 
+  describe "#when_committed!" do
+    before do
+      Backgrounder.reset
+    end
+    let(:model) { Widget.new }
+
+    context "when not running within a transaction" do
+      it "runs the block immediately" do
+        model.needs_to_happen
+        Backgrounder.jobs.should == [:important_work]
+      end
+    end
+
+    context "when running within a transaction" do
+      it "does not run the provided block until the transaction is committed" do
+        Widget.transaction do
+          model.needs_to_happen
+          Backgrounder.jobs.should be_empty
+          model.save
+          Backgrounder.jobs.should be_empty
+        end
+        Backgrounder.jobs.should == [:important_work]
+      end
+    end
+
+  end
+
   describe "#when_committed" do
     before do
       Backgrounder.reset
@@ -83,6 +110,9 @@ class Widget < ActiveRecord::Base
   def action_that_needs_follow_up_after_commit
     when_committed { Backgrounder.enqueue :important_work }
   end
+  def needs_to_happen
+    when_committed! { Backgrounder.enqueue :important_work }
+  end
   def another_action_with_follow_up
     when_committed { Backgrounder.enqueue :more_work }
   end