Introduce queue client "plugin" namespace and interface, with a Stomp client implementation.

Puppet::Util::Queue provides queue client mix-in behaviors that enable easy queue client management for consumer classes.  Some relevant behaviors include:
* standard Puppet instance loader behavior for loading queue client modules on-demand based on the client module specified by symbolic name
* singleton registry of known queue client types (based on symbol-to-class mappings from the instance loading behavior)
* simple interface for working with an actual queue client instance

Puppet::Util::Queue::Stomp wraps the Stomp::Client class to provide an initial queue client option supporting the Stomp messaging protocol.  This defines the interface for all Puppet queue client plugins going forward.

1 files changed, 95 insertions, 0 deletions

diff --git a/spec/unit/util/queue.rb b/spec/unit/util/queue.rb
new file mode 100755
index 000000000..525e6239f
--- /dev/null
+++ b/spec/unit/util/queue.rb
@@ -0,0 +1,95 @@
+#!/usr/bin/env ruby
+
+require File.dirname(__FILE__) + '/../../spec_helper'
+require 'puppet/util/queue'
+require 'spec/mocks'
+
+def make_test_client_class(n)
+    c = Class.new do
+        class <<self
+            attr_accessor :name
+            def to_s
+                name
+            end
+        end
+    end
+    c.name = n
+    c
+end
+
+mod = Puppet::Util::Queue
+client_classes = { :default => make_test_client_class('Bogus::Default'), :setup => make_test_client_class('Bogus::Setup') }
+mod.register_queue_type(client_classes[:default], :default)
+mod.register_queue_type(client_classes[:setup], :setup)
+
+describe Puppet::Util::Queue do
+    before :each do
+        @class = Class.new do
+            extend mod
+            self.queue_type_default = :default
+        end
+    end
+
+    context 'when determining a type name from a class' do
+        it 'should handle a simple one-word class name' do
+            mod.queue_type_from_class(make_test_client_class('Foo')).should == :foo
+        end
+
+        it 'should handle a simple two-word class name' do
+            mod.queue_type_from_class(make_test_client_class('FooBar')).should == :foo_bar
+        end
+
+        it 'should handle a two-part class name with one terminating word' do
+            mod.queue_type_from_class(make_test_client_class('Foo::Bar')).should == :bar
+        end
+
+        it 'should handle a two-part class name with two terminating words' do
+            mod.queue_type_from_class(make_test_client_class('Foo::BarBah')).should == :bar_bah
+        end
+    end
+
+    context 'when registering a queue client class' do
+        c = make_test_client_class('Foo::Bogus')
+        it 'uses the proper default name logic when type is unspecified' do
+            mod.register_queue_type(c)
+            mod.queue_type_to_class(:bogus).should == c
+        end
+
+        it 'uses an explicit type name when provided' do
+            mod.register_queue_type(c, :aardvark)
+            mod.queue_type_to_class(:aardvark).should == c
+        end
+
+        it 'throws an exception when type names conflict' do
+            mod.register_queue_type( make_test_client_class('Conflict') )
+            lambda { mod.register_queue_type( c, :conflict) }.should raise_error
+        end
+
+        it 'handle multiple, non-conflicting registrations' do
+            a = make_test_client_class('TestA')
+            b = make_test_client_class('TestB')
+            mod.register_queue_type(a)
+            mod.register_queue_type(b)
+            mod.queue_type_to_class(:test_a).should == a
+            mod.queue_type_to_class(:test_b).should == b
+        end
+
+        it 'throws an exception when type name is unknown' do
+            lambda { mod.queue_type_to_class(:nope) }.should raise_error
+        end
+    end
+
+    context 'when determining client type' do
+        it 'returns client class based on queue_type_default' do
+            Puppet.settings.stubs(:value).returns(nil)
+            @class.client_class.should == client_classes[:default]
+            @class.client.class.should == client_classes[:default]
+        end
+
+        it 'prefers settings variable for client class when specified' do
+            Puppet.settings.stubs(:value).with(:queue_client).returns(:setup)
+            @class.client_class.should == client_classes[:setup]
+            @class.client.class.should == client_classes[:setup]
+        end
+    end
+end