The check for existing exchanges was flawed, and therefore, on each

Puppet run, they were re-created.

Restructure the code, to get rid of the bogus/broken parse_command method.
Fix the test after the updated exchange provider

lib/puppet/provider/rabbitmq_exchange/rabbitmqadmin.rb

@@ -25,38 +25,28 @@ def should_vhost
 
   def self.all_vhosts
     vhosts = []
-    parse_command(
-      self.run_with_retries {
-        rabbitmqctl('list_vhosts')
-      }
-    ).collect do |vhost|
-        vhosts.push(vhost)
+    self.run_with_retries {
+      rabbitmqctl('-q', 'list_vhosts')
+    }.split(/\n/).each do |vhost|
+      vhosts.push(vhost)
     end
     vhosts
   end
 
   def self.all_exchanges(vhost)
     exchanges = []
-    parse_command(
-      self.run_with_retries {
-        rabbitmqctl('list_exchanges', '-p', vhost, 'name', 'type')
-      }
-    )
-  end
-
-  def self.parse_command(cmd_output)
-    # first line is:
-    # Listing exchanges/vhosts ...
-    # while the last line is
-    # ...done.
-    #
-    cmd_output.split(/\n/)[1..-2]
+    self.run_with_retries {
+      rabbitmqctl('-q', 'list_exchanges', '-p', vhost, 'name', 'type')
+    }.split(/\n/).each do |exchange|
+      exchanges.push(exchange)
+    end
+    exchanges
   end
 
   def self.instances
     resources = []
     all_vhosts.each do |vhost|
-        all_exchanges(vhost).collect do |line|
+        all_exchanges(vhost).each do |line|
             name, type = line.split()
             if type.nil?
                 # if name is empty, it will wrongly get the type's value.

spec/unit/puppet/provider/rabbitmq_exchange/rabbitmqadmin_spec.rb

@@ -14,13 +14,10 @@
   end
 
   it 'should return instances' do
-    provider_class.expects(:rabbitmqctl).with('list_vhosts').returns <<-EOT
-Listing vhosts ...
+    provider_class.expects(:rabbitmqctl).with('-q', 'list_vhosts').returns <<-EOT
 /
-...done.
 EOT
-    provider_class.expects(:rabbitmqctl).with('list_exchanges', '-p', '/', 'name', 'type').returns <<-EOT
-Listing exchanges ...
+    provider_class.expects(:rabbitmqctl).with('-q', 'list_exchanges', '-p', '/', 'name', 'type').returns <<-EOT
         direct
 	amq.direct      direct
 	amq.fanout      fanout
@@ -29,7 +26,6 @@
 	amq.rabbitmq.log        topic
 	amq.rabbitmq.trace      topic
 	amq.topic       topic
-	...done.
 EOT
     instances = provider_class.instances
     instances.size.should == 8