diff --git a/lib/puppet/transaction.rb b/lib/puppet/transaction.rb
index ab74ed385..16887454c 100644
--- a/lib/puppet/transaction.rb
+++ b/lib/puppet/transaction.rb
@@ -1,340 +1,369 @@
 require 'puppet'
 require 'puppet/util/tagging'
 require 'puppet/application'
 require 'digest/sha1'
 require 'set'
 
 # the class that actually walks our resource/property tree, collects the changes,
 # and performs them
 #
 # @api private
 class Puppet::Transaction
   require 'puppet/transaction/additional_resource_generator'
   require 'puppet/transaction/event'
   require 'puppet/transaction/event_manager'
   require 'puppet/transaction/resource_harness'
   require 'puppet/resource/status'
 
   attr_accessor :catalog, :ignoreschedules, :for_network_device
 
   # The report, once generated.
   attr_reader :report
 
   # Routes and stores any events and subscriptions.
   attr_reader :event_manager
 
   # Handles most of the actual interacting with resources
   attr_reader :resource_harness
 
   attr_reader :prefetched_providers
 
   include Puppet::Util
   include Puppet::Util::Tagging
 
   def initialize(catalog, report, prioritizer)
     @catalog = catalog
 
     @report = report || Puppet::Transaction::Report.new("apply", catalog.version, catalog.environment)
 
     @prioritizer = prioritizer
 
     @report.add_times(:config_retrieval, @catalog.retrieval_duration || 0)
 
     @event_manager = Puppet::Transaction::EventManager.new(self)
 
     @resource_harness = Puppet::Transaction::ResourceHarness.new(self)
 
     @prefetched_providers = Hash.new { |h,k| h[k] = {} }
   end
 
+  # Invoke the pre_run_check hook in every resource in the catalog.
+  # This should (only) be called by Transaction#evaluate before applying
+  # the catalog.
+  #
+  # @see Puppet::Transaction#evaluate
+  # @see Puppet::Type#pre_run_check
+  # @raises Puppet::Error
+  # @return void
+  def perform_pre_run_checks
+    prerun_errors = {}
+
+    @catalog.vertices.each do |res|
+      begin
+        res.pre_run_check
+      rescue Puppet::Error => detail
+        prerun_errors[res] = detail
+      end
+    end
+
+    unless prerun_errors.empty?
+      prerun_errors.each do |res,detail|
+        Puppet.err "#{res.ref} check error: #{detail}"
+      end
+      raise Puppet::Error, "some pre-run checks failed"
+    end
+  end
+
   # This method does all the actual work of running a transaction.  It
   # collects all of the changes, executes them, and responds to any
   # necessary events.
   def evaluate(&block)
     block ||= method(:eval_resource)
     generator = AdditionalResourceGenerator.new(@catalog, relationship_graph, @prioritizer)
     @catalog.vertices.each { |resource| generator.generate_additional_resources(resource) }
 
+    perform_pre_run_checks
+
     Puppet.info "Applying configuration version '#{catalog.version}'" if catalog.version
 
     continue_while = lambda { !stop_processing? }
 
     post_evalable_providers = Set.new
     pre_process = lambda do |resource|
       prov_class = resource.provider.class
       post_evalable_providers << prov_class if prov_class.respond_to?(:post_resource_eval)
 
       prefetch_if_necessary(resource)
 
       # If we generated resources, we don't know what they are now
       # blocking, so we opt to recompute it, rather than try to track every
       # change that would affect the number.
       relationship_graph.clear_blockers if generator.eval_generate(resource)
     end
 
     providerless_types = []
     overly_deferred_resource_handler = lambda do |resource|
       # We don't automatically assign unsuitable providers, so if there
       # is one, it must have been selected by the user.
       if resource.provider
         resource.err "Provider #{resource.provider.class.name} is not functional on this host"
       else
         providerless_types << resource.type
       end
 
       resource_status(resource).failed = true
     end
 
     canceled_resource_handler = lambda do |resource|
       resource_status(resource).skipped = true
       resource.debug "Transaction canceled, skipping"
     end
 
     teardown = lambda do
       # Just once per type. No need to punish the user.
       providerless_types.uniq.each do |type|
         Puppet.err "Could not find a suitable provider for #{type}"
       end
 
       post_evalable_providers.each do |provider|
         begin
           provider.post_resource_eval
         rescue => detail
           Puppet.log_exception(detail, "post_resource_eval failed for provider #{provider}")
         end
       end
     end
 
     relationship_graph.traverse(:while => continue_while,
                                 :pre_process => pre_process,
                                 :overly_deferred_resource_handler => overly_deferred_resource_handler,
                                 :canceled_resource_handler => canceled_resource_handler,
                                 :teardown => teardown) do |resource|
       if resource.is_a?(Puppet::Type::Component)
         Puppet.warning "Somehow left a component in the relationship graph"
       else
         resource.info "Starting to evaluate the resource" if Puppet[:evaltrace] and @catalog.host_config?
         seconds = thinmark { block.call(resource) }
         resource.info "Evaluated in %0.2f seconds" % seconds if Puppet[:evaltrace] and @catalog.host_config?
       end
     end
 
     Puppet.debug "Finishing transaction #{object_id}"
   end
 
   # Wraps application run state check to flag need to interrupt processing
   def stop_processing?
     Puppet::Application.stop_requested? && catalog.host_config?
   end
 
   # Are there any failed resources in this transaction?
   def any_failed?
     report.resource_statuses.values.detect { |status| status.failed? }
   end
 
   # Find all of the changed resources.
   def changed?
     report.resource_statuses.values.find_all { |status| status.changed }.collect { |status| catalog.resource(status.resource) }
   end
 
   def relationship_graph
     catalog.relationship_graph
   end
 
   def resource_status(resource)
     report.resource_statuses[resource.to_s] || add_resource_status(Puppet::Resource::Status.new(resource))
   end
 
   # The tags we should be checking.
   def tags
     self.tags = Puppet[:tags] unless defined?(@tags)
 
     super
   end
 
   def prefetch_if_necessary(resource)
     provider_class = resource.provider.class
     return unless provider_class.respond_to?(:prefetch) and !prefetched_providers[resource.type][provider_class.name]
 
     resources = resources_by_provider(resource.type, provider_class.name)
 
     if provider_class == resource.class.defaultprovider
       providerless_resources = resources_by_provider(resource.type, nil)
       providerless_resources.values.each {|res| res.provider = provider_class.name}
       resources.merge! providerless_resources
     end
 
     prefetch(provider_class, resources)
   end
 
   private
 
   # Apply all changes for a resource
   def apply(resource, ancestor = nil)
     status = resource_harness.evaluate(resource)
     add_resource_status(status)
     event_manager.queue_events(ancestor || resource, status.events) unless status.failed?
   rescue => detail
     resource.err "Could not evaluate: #{detail}"
   end
 
   # Evaluate a single resource.
   def eval_resource(resource, ancestor = nil)
     if skip?(resource)
       resource_status(resource).skipped = true
     else
       resource_status(resource).scheduled = true
       apply(resource, ancestor)
     end
 
     # Check to see if there are any events queued for this resource
     event_manager.process_events(resource)
   end
 
   def failed?(resource)
     s = resource_status(resource) and s.failed?
   end
 
   # Does this resource have any failed dependencies?
   def failed_dependencies?(resource)
     # First make sure there are no failed dependencies.  To do this,
     # we check for failures in any of the vertexes above us.  It's not
     # enough to check the immediate dependencies, which is why we use
     # a tree from the reversed graph.
     found_failed = false
 
 
     # When we introduced the :whit into the graph, to reduce the combinatorial
     # explosion of edges, we also ended up reporting failures for containers
     # like class and stage.  This is undesirable; while just skipping the
     # output isn't perfect, it is RC-safe. --daniel 2011-06-07
     suppress_report = (resource.class == Puppet::Type.type(:whit))
 
     relationship_graph.dependencies(resource).each do |dep|
       next unless failed?(dep)
       found_failed = true
 
       # See above. --daniel 2011-06-06
       unless suppress_report then
         resource.notice "Dependency #{dep} has failures: #{resource_status(dep).failed}"
       end
     end
 
     found_failed
   end
 
   # A general method for recursively generating new resources from a
   # resource.
   def generate_additional_resources(resource)
     return unless resource.respond_to?(:generate)
     begin
       made = resource.generate
     rescue => detail
       resource.log_exception(detail, "Failed to generate additional resources using 'generate': #{detail}")
     end
     return unless made
     made = [made] unless made.is_a?(Array)
     made.uniq.each do |res|
       begin
         res.tag(*resource.tags)
         @catalog.add_resource(res)
         res.finish
         add_conditional_directed_dependency(resource, res)
         generate_additional_resources(res)
       rescue Puppet::Resource::Catalog::DuplicateResourceError
         res.info "Duplicate generated resource; skipping"
       end
     end
   end
 
   # Should we ignore tags?
   def ignore_tags?
     ! @catalog.host_config?
   end
 
   def resources_by_provider(type_name, provider_name)
     unless @resources_by_provider
       @resources_by_provider = Hash.new { |h, k| h[k] = Hash.new { |h, k| h[k] = {} } }
 
       @catalog.vertices.each do |resource|
         if resource.class.attrclass(:provider)
           prov = resource.provider && resource.provider.class.name
           @resources_by_provider[resource.type][prov][resource.name] = resource
         end
       end
     end
 
     @resources_by_provider[type_name][provider_name] || {}
   end
 
   # Prefetch any providers that support it, yo.  We don't support prefetching
   # types, just providers.
   def prefetch(provider_class, resources)
     type_name = provider_class.resource_type.name
     return if @prefetched_providers[type_name][provider_class.name]
     Puppet.debug "Prefetching #{provider_class.name} resources for #{type_name}"
     begin
       provider_class.prefetch(resources)
     rescue => detail
       Puppet.log_exception(detail, "Could not prefetch #{type_name} provider '#{provider_class.name}': #{detail}")
     end
     @prefetched_providers[type_name][provider_class.name] = true
   end
 
   def add_resource_status(status)
     report.add_resource_status(status)
   end
 
   # Is the resource currently scheduled?
   def scheduled?(resource)
     self.ignoreschedules or resource_harness.scheduled?(resource)
   end
 
   # Should this resource be skipped?
   def skip?(resource)
     if missing_tags?(resource)
       resource.debug "Not tagged with #{tags.join(", ")}"
     elsif ! scheduled?(resource)
       resource.debug "Not scheduled"
     elsif failed_dependencies?(resource)
       # When we introduced the :whit into the graph, to reduce the combinatorial
       # explosion of edges, we also ended up reporting failures for containers
       # like class and stage.  This is undesirable; while just skipping the
       # output isn't perfect, it is RC-safe. --daniel 2011-06-07
       unless resource.class == Puppet::Type.type(:whit) then
         resource.warning "Skipping because of failed dependencies"
       end
     elsif resource.virtual?
       resource.debug "Skipping because virtual"
     elsif !host_and_device_resource?(resource) && resource.appliable_to_host? && for_network_device
       resource.debug "Skipping host resources because running on a device"
     elsif !host_and_device_resource?(resource) && resource.appliable_to_device? && !for_network_device
       resource.debug "Skipping device resources because running on a posix host"
     else
       return false
     end
     true
   end
 
   def host_and_device_resource?(resource)
     resource.appliable_to_host? && resource.appliable_to_device?
   end
 
   def handle_qualified_tags( qualified )
     # The default behavior of Puppet::Util::Tagging is
     # to split qualified tags into parts. That would cause
     # qualified tags to match too broadly here.
     return
   end
 
   # Is this resource tagged appropriately?
   def missing_tags?(resource)
     return false if ignore_tags?
     return false if tags.empty?
 
     not resource.tagged?(*tags)
   end
 end
 
 require 'puppet/transaction/report'
 
diff --git a/lib/puppet/type.rb b/lib/puppet/type.rb
index f382f30ca..befa3c8a0 100644
--- a/lib/puppet/type.rb
+++ b/lib/puppet/type.rb
@@ -1,2430 +1,2446 @@
 require 'puppet'
 require 'puppet/util/log'
 require 'puppet/util/metric'
 require 'puppet/property'
 require 'puppet/parameter'
 require 'puppet/util'
 require 'puppet/util/autoload'
 require 'puppet/metatype/manager'
 require 'puppet/util/errors'
 require 'puppet/util/logging'
 require 'puppet/util/tagging'
 
 # see the bottom of the file for the rest of the inclusions
 
 
 module Puppet
 # The base class for all Puppet types.
 #
 # A type describes:
 #--
 # * **Attributes** - properties, parameters, and meta-parameters are different types of attributes of a type.
 #   * **Properties** - these are the properties of the managed resource (attributes of the entity being managed; like
 #     a file's owner, group and mode). A property describes two states; the 'is' (current state) and the 'should' (wanted
 #     state).
 #       * **Ensurable** - a set of traits that control the lifecycle (create, remove, etc.) of a managed entity.
 #         There is a default set of operations associated with being _ensurable_, but this can be changed.
 #       * **Name/Identity** - one property is the name/identity of a resource, the _namevar_ that uniquely identifies
 #         one instance of a type from all others.
 #   * **Parameters** - additional attributes of the type (that does not directly related to an instance of the managed
 #     resource; if an operation is recursive or not, where to look for things, etc.). A Parameter (in contrast to Property)
 #     has one current value where a Property has two (current-state and wanted-state).
 #   * **Meta-Parameters** - parameters that are available across all types. A meta-parameter typically has
 #     additional semantics; like the `require` meta-parameter. A new type typically does not add new meta-parameters,
 #     but you need to be aware of their existence so you do not inadvertently shadow an existing meta-parameters.
 # * **Parent** - a type can have a super type (that it inherits from).
 # * **Validation** - If not just a basic data type, or an enumeration of symbolic values, it is possible to provide
 #     validation logic for a type, properties and parameters.
 # * **Munging** - munging/unmunging is the process of turning a value in external representation (as used
 #     by a provider) into an internal representation and vice versa. A Type supports adding custom logic for these.
 # * **Auto Requirements** - a type can specify automatic relationships to resources to ensure that if they are being
 #     managed, they will be processed before this type.
 # * **Providers** - a provider is an implementation of a type's behavior - the management of a resource in the
 #     system being managed. A provider is often platform specific and is selected at runtime based on
 #     criteria/predicates specified in the configured providers. See {Puppet::Provider} for details.
 # * **Device Support** - A type has some support for being applied to a device; i.e. something that is managed
 #     by running logic external to the device itself. There are several methods that deals with type
 #     applicability for these special cases such as {apply_to_device}.
 #
 # Additional Concepts:
 # --
 # * **Resource-type** - A _resource type_ is a term used to denote the type of a resource; internally a resource
 #     is really an instance of a Ruby class i.e. {Puppet::Resource} which defines its behavior as "resource data".
 #     Conceptually however, a resource is an instance of a subclass of Type (e.g. File), where such a class describes
 #     its interface (what can be said/what is known about a resource of this type),
 # * **Managed Entity** - This is not a term in general use, but is used here when there is a need to make
 #     a distinction between a resource (a description of what/how something should be managed), and what it is
 #     managing (a file in the file system). The term _managed entity_ is a reference to the "file in the file system"
 # * **Isomorphism** - the quality of being _isomorphic_ means that two resource instances with the same name
 #     refers to the same managed entity. Or put differently; _an isomorphic name is the identity of a resource_.
 #     As an example, `exec` resources (that executes some command) have the command (i.e. the command line string) as
 #     their name, and these resources are said to be non-isomorphic.
 #
 # @note The Type class deals with multiple concerns; some methods provide an internal DSL for convenient definition
 #   of types, other methods deal with various aspects while running; wiring up a resource (expressed in Puppet DSL
 #   or Ruby DSL) with its _resource type_ (i.e. an instance of Type) to enable validation, transformation of values
 #   (munge/unmunge), etc. Lastly, Type is also responsible for dealing with Providers; the concrete implementations
 #   of the behavior that constitutes how a particular Type behaves on a particular type of system (e.g. how
 #   commands are executed on a flavor of Linux, on Windows, etc.). This means that as you are reading through the
 #   documentation of this class, you will be switching between these concepts, as well as switching between
 #   the conceptual level "a resource is an instance of a resource-type" and the actual implementation classes
 #   (Type, Resource, Provider, and various utility and helper classes).
 #
 # @api public
 #
 #
 class Type
   include Puppet::Util
   include Puppet::Util::Errors
   include Puppet::Util::Logging
   include Puppet::Util::Tagging
 
   # Comparing type instances.
   include Comparable
 
   # Compares this type against the given _other_ (type) and returns -1, 0, or +1 depending on the order.
   # @param other [Object] the object to compare against (produces nil, if not kind of Type}
   # @return [-1, 0, +1, nil] produces -1 if this type is before the given _other_ type, 0 if equals, and 1 if after.
   #   Returns nil, if the given _other_ is not a kind of Type.
   # @see Comparable
   #
   def <=>(other)
     # We only order against other types, not arbitrary objects.
     return nil unless other.is_a? Puppet::Type
     # Our natural order is based on the reference name we use when comparing
     # against other type instances.
     self.ref <=> other.ref
   end
 
   # Code related to resource type attributes.
   class << self
     include Puppet::Util::ClassGen
     include Puppet::Util::Warnings
 
     # @return [Array<Puppet::Property>] The list of declared properties for the resource type.
     # The returned lists contains instances if Puppet::Property or its subclasses.
     attr_reader :properties
   end
 
   # Returns all the attribute names of the type in the appropriate order.
   # The {key_attributes} come first, then the {provider}, then the {properties}, and finally
   # the {parameters} and {metaparams},
   # all in the order they were specified in the respective files.
   # @return [Array<String>] all type attribute names in a defined order.
   #
   def self.allattrs
     key_attributes | (parameters & [:provider]) | properties.collect { |property| property.name } | parameters | metaparams
   end
 
   # Returns the class associated with the given attribute name.
   # @param name [String] the name of the attribute to obtain the class for
   # @return [Class, nil] the class for the given attribute, or nil if the name does not refer to an existing attribute
   #
   def self.attrclass(name)
     @attrclasses ||= {}
 
     # We cache the value, since this method gets called such a huge number
     # of times (as in, hundreds of thousands in a given run).
     unless @attrclasses.include?(name)
       @attrclasses[name] = case self.attrtype(name)
       when :property; @validproperties[name]
       when :meta; @@metaparamhash[name]
       when :param; @paramhash[name]
       end
     end
     @attrclasses[name]
   end
 
   # Returns the attribute type (`:property`, `;param`, `:meta`).
   # @comment What type of parameter are we dealing with? Cache the results, because
   #   this method gets called so many times.
   # @return [Symbol] a symbol describing the type of attribute (`:property`, `;param`, `:meta`)
   #
   def self.attrtype(attr)
     @attrtypes ||= {}
     unless @attrtypes.include?(attr)
       @attrtypes[attr] = case
         when @validproperties.include?(attr); :property
         when @paramhash.include?(attr); :param
         when @@metaparamhash.include?(attr); :meta
         end
     end
 
     @attrtypes[attr]
   end
 
   # Provides iteration over meta-parameters.
   # @yieldparam p [Puppet::Parameter] each meta parameter
   # @return [void]
   #
   def self.eachmetaparam
     @@metaparams.each { |p| yield p.name }
   end
 
   # Creates a new `ensure` property with configured default values or with configuration by an optional block.
   # This method is a convenience method for creating a property `ensure` with default accepted values.
   # If no block is specified, the new `ensure` property will accept the default symbolic
   # values `:present`, and `:absent` - see {Puppet::Property::Ensure}.
   # If something else is wanted, pass a block and make calls to {Puppet::Property.newvalue} from this block
   # to define each possible value. If a block is passed, the defaults are not automatically added to the set of
   # valid values.
   #
   # @note This method will be automatically called without a block if the type implements the methods
   #   specified by {ensurable?}. It is recommended to always call this method and not rely on this automatic
   #   specification to clearly state that the type is ensurable.
   #
   # @overload ensurable()
   # @overload ensurable({|| ... })
   # @yield [ ] A block evaluated in scope of the new Parameter
   # @yieldreturn [void]
   # @return [void]
   # @dsl type
   # @api public
   #
   def self.ensurable(&block)
     if block_given?
       self.newproperty(:ensure, :parent => Puppet::Property::Ensure, &block)
     else
       self.newproperty(:ensure, :parent => Puppet::Property::Ensure) do
         self.defaultvalues
       end
     end
   end
 
   # Returns true if the type implements the default behavior expected by being _ensurable_ "by default".
   # A type is _ensurable_ by default if it responds to `:exists`, `:create`, and `:destroy`.
   # If a type implements these methods and have not already specified that it is _ensurable_, it will be
   # made so with the defaults specified in {ensurable}.
   # @return [Boolean] whether the type is _ensurable_ or not.
   #
   def self.ensurable?
     # If the class has all three of these methods defined, then it's
     # ensurable.
     [:exists?, :create, :destroy].all? { |method|
       self.public_method_defined?(method)
     }
   end
 
   # @comment These `apply_to` methods are horrible.  They should really be implemented
   #   as part of the usual system of constraints that apply to a type and
   #   provider pair, but were implemented as a separate shadow system.
   #
   # @comment We should rip them out in favour of a real constraint pattern around the
   #   target device - whatever that looks like - and not have this additional
   #   magic here. --daniel 2012-03-08
   #
   # Makes this type applicable to `:device`.
   # @return [Symbol] Returns `:device`
   # @api private
   #
   def self.apply_to_device
     @apply_to = :device
   end
 
   # Makes this type applicable to `:host`.
   # @return [Symbol] Returns `:host`
   # @api private
   #
   def self.apply_to_host
     @apply_to = :host
   end
 
   # Makes this type applicable to `:both` (i.e. `:host` and `:device`).
   # @return [Symbol] Returns `:both`
   # @api private
   #
   def self.apply_to_all
     @apply_to = :both
   end
 
   # Makes this type apply to `:host` if not already applied to something else.
   # @return [Symbol] a `:device`, `:host`, or `:both` enumeration
   # @api private
   def self.apply_to
     @apply_to ||= :host
   end
 
   # Returns true if this type is applicable to the given target.
   # @param target [Symbol] should be :device, :host or :target, if anything else, :host is enforced
   # @return [Boolean] true
   # @api private
   #
   def self.can_apply_to(target)
     [ target == :device ? :device : :host, :both ].include?(apply_to)
   end
 
   # Processes the options for a named parameter.
   # @param name [String] the name of a parameter
   # @param options [Hash] a hash of options
   # @option options [Boolean] :boolean if option set to true, an access method on the form _name_? is added for the param
   # @return [void]
   #
   def self.handle_param_options(name, options)
     # If it's a boolean parameter, create a method to test the value easily
     if options[:boolean]
       define_method(name.to_s + "?") do
         val = self[name]
         if val == :true or val == true
           return true
         end
       end
     end
   end
 
   # Is the given parameter a meta-parameter?
   # @return [Boolean] true if the given parameter is a meta-parameter.
   #
   def self.metaparam?(param)
     @@metaparamhash.include?(param.intern)
   end
 
   # Returns the meta-parameter class associated with the given meta-parameter name.
   # Accepts a `nil` name, and return nil.
   # @param name [String, nil] the name of a meta-parameter
   # @return [Class,nil] the class for the given meta-parameter, or `nil` if no such meta-parameter exists, (or if
   #   the given meta-parameter name is `nil`.
   #
   def self.metaparamclass(name)
     return nil if name.nil?
     @@metaparamhash[name.intern]
   end
 
   # Returns all meta-parameter names.
   # @return [Array<String>] all meta-parameter names
   #
   def self.metaparams
     @@metaparams.collect { |param| param.name }
   end
 
   # Returns the documentation for a given meta-parameter of this type.
   # @todo the type for the param metaparam
   # @param metaparam [??? Puppet::Parameter] the meta-parameter to get documentation for.
   # @return [String] the documentation associated with the given meta-parameter, or nil of not such documentation
   #   exists.
   # @raise if the given metaparam is not a meta-parameter in this type
   #
   def self.metaparamdoc(metaparam)
     @@metaparamhash[metaparam].doc
   end
 
   # Creates a new meta-parameter.
   # This creates a new meta-parameter that is added to all types.
   # @param name [Symbol] the name of the parameter
   # @param options [Hash] a hash with options.
   # @option options [Class<inherits Puppet::Parameter>] :parent (Puppet::Parameter) the super class of this parameter
   # @option options [Hash{String => Object}] :attributes a hash that is applied to the generated class
   #   by calling setter methods corresponding to this hash's keys/value pairs. This is done before the given
   #   block is evaluated.
   # @option options [Boolean] :boolean (false) specifies if this is a boolean parameter
   # @option options [Boolean] :namevar  (false) specifies if this parameter is the namevar
   # @option options [Symbol, Array<Symbol>] :required_features  specifies required provider features by name
   # @return [Class<inherits Puppet::Parameter>] the created parameter
   # @yield [ ] a required block that is evaluated in the scope of the new meta-parameter
   # @api public
   # @dsl type
   # @todo Verify that this description is ok
   #
   def self.newmetaparam(name, options = {}, &block)
     @@metaparams ||= []
     @@metaparamhash ||= {}
     name = name.intern
 
     param = genclass(
       name,
       :parent => options[:parent] || Puppet::Parameter,
       :prefix => "MetaParam",
       :hash => @@metaparamhash,
       :array => @@metaparams,
       :attributes => options[:attributes],
       &block
     )
 
     # Grr.
     param.required_features = options[:required_features] if options[:required_features]
 
     handle_param_options(name, options)
 
     param.metaparam = true
 
     param
   end
 
   # Returns parameters that act as a key.
   # All parameters that return true from #isnamevar? or is named `:name` are included in the returned result.
   # @todo would like a better explanation
   # @return [Array<Puppet::Parameter>] WARNING: this return type is uncertain
   def self.key_attribute_parameters
     @key_attribute_parameters ||= (
       @parameters.find_all { |param|
         param.isnamevar? or param.name == :name
       }
     )
   end
 
   # Returns cached {key_attribute_parameters} names
   # @todo what is a 'key_attribute' ?
   # @return [Array<String>] cached key_attribute names
   #
   def self.key_attributes
     # This is a cache miss around 0.05 percent of the time. --daniel 2012-07-17
     @key_attributes_cache ||= key_attribute_parameters.collect { |p| p.name }
   end
 
   # Returns a mapping from the title string to setting of attribute value(s).
   # This default implementation provides a mapping of title to the one and only _namevar_ present
   # in the type's definition.
   # @note Advanced: some logic requires this mapping to be done differently, using a different
   #   validation/pattern, breaking up the title
   #   into several parts assigning each to an individual attribute, or even use a composite identity where
   #   all namevars are seen as part of the unique identity (such computation is done by the {#uniqueness} method.
   #   These advanced options are rarely used (only one of the built in puppet types use this, and then only
   #   a small part of the available functionality), and the support for these advanced mappings is not
   #   implemented in a straight forward way. For these reasons, this method has been marked as private).
   #
   # @raise [Puppet::DevError] if there is no title pattern and there are two or more key attributes
   # @return [Array<Array<Regexp, Array<Array <Symbol, Proc>>>>, nil] a structure with a regexp and the first key_attribute ???
   # @comment This wonderful piece of logic creates a structure used by Resource.parse_title which
   #   has the capability to assign parts of the title to one or more attributes; It looks like an implementation
   #   of a composite identity key (all parts of the key_attributes array are in the key). This can also
   #   be seen in the method uniqueness_key.
   #   The implementation in this method simply assigns the title to the one and only namevar (which is name
   #   or a variable marked as namevar).
   #   If there are multiple namevars (any in addition to :name?) then this method MUST be implemented
   #   as it raises an exception if there is more than 1. Note that in puppet, it is only File that uses this
   #   to create a different pattern for assigning to the :path attribute
   #   This requires further digging.
   #   The entire construct is somewhat strange, since resource checks if the method "title_patterns" is
   #   implemented (it seems it always is) - why take this more expensive regexp mathching route for all
   #   other types?
   # @api private
   #
   def self.title_patterns
     case key_attributes.length
     when 0; []
     when 1;
       [ [ /(.*)/m, [ [key_attributes.first] ] ] ]
     else
       raise Puppet::DevError,"you must specify title patterns when there are two or more key attributes"
     end
   end
 
   # Produces a _uniqueness_key_
   # @todo Explain what a uniqueness_key is
   # @return [Object] an object that is a _uniqueness_key_ for this object
   #
   def uniqueness_key
     self.class.key_attributes.sort_by { |attribute_name| attribute_name.to_s }.map{ |attribute_name| self[attribute_name] }
   end
 
   # Creates a new parameter.
   # @param name [Symbol] the name of the parameter
   # @param options [Hash] a hash with options.
   # @option options [Class<inherits Puppet::Parameter>] :parent (Puppet::Parameter) the super class of this parameter
   # @option options [Hash{String => Object}] :attributes a hash that is applied to the generated class
   #   by calling setter methods corresponding to this hash's keys/value pairs. This is done before the given
   #   block is evaluated.
   # @option options [Boolean] :boolean (false) specifies if this is a boolean parameter
   # @option options [Boolean] :namevar  (false) specifies if this parameter is the namevar
   # @option options [Symbol, Array<Symbol>] :required_features  specifies required provider features by name
   # @return [Class<inherits Puppet::Parameter>] the created parameter
   # @yield [ ] a required block that is evaluated in the scope of the new parameter
   # @api public
   # @dsl type
   #
   def self.newparam(name, options = {}, &block)
     options[:attributes] ||= {}
 
     param = genclass(
       name,
       :parent     => options[:parent] || Puppet::Parameter,
       :attributes => options[:attributes],
       :block      => block,
       :prefix     => "Parameter",
       :array      => @parameters,
       :hash       => @paramhash
     )
 
     handle_param_options(name, options)
 
     # Grr.
     param.required_features = options[:required_features] if options[:required_features]
 
     param.isnamevar if options[:namevar]
 
     param
   end
 
   # Creates a new property.
   # @param name [Symbol] the name of the property
   # @param options [Hash] a hash with options.
   # @option options [Symbol] :array_matching (:first) specifies how the current state is matched against
   #   the wanted state. Use `:first` if the property is single valued, and (`:all`) otherwise.
   # @option options [Class<inherits Puppet::Property>] :parent (Puppet::Property) the super class of this property
   # @option options [Hash{String => Object}] :attributes a hash that is applied to the generated class
   #   by calling setter methods corresponding to this hash's keys/value pairs. This is done before the given
   #   block is evaluated.
   # @option options [Boolean] :boolean (false) specifies if this is a boolean parameter
   # @option options [Symbol] :retrieve the method to call on the provider (or `parent` if `provider` is not set)
   #   to retrieve the current value of this property.
   # @option options [Symbol, Array<Symbol>] :required_features  specifies required provider features by name
   # @return [Class<inherits Puppet::Property>] the created property
   # @yield [ ] a required block that is evaluated in the scope of the new property
   # @api public
   # @dsl type
   #
   def self.newproperty(name, options = {}, &block)
     name = name.intern
 
     # This is here for types that might still have the old method of defining
     # a parent class.
     unless options.is_a? Hash
       raise Puppet::DevError,
         "Options must be a hash, not #{options.inspect}"
     end
 
     raise Puppet::DevError, "Class #{self.name} already has a property named #{name}" if @validproperties.include?(name)
 
     if parent = options[:parent]
       options.delete(:parent)
     else
       parent = Puppet::Property
     end
 
     # We have to create our own, new block here because we want to define
     # an initial :retrieve method, if told to, and then eval the passed
     # block if available.
     prop = genclass(name, :parent => parent, :hash => @validproperties, :attributes => options) do
       # If they've passed a retrieve method, then override the retrieve
       # method on the class.
       if options[:retrieve]
         define_method(:retrieve) do
           provider.send(options[:retrieve])
         end
       end
 
       class_eval(&block) if block
     end
 
     # If it's the 'ensure' property, always put it first.
     if name == :ensure
       @properties.unshift prop
     else
       @properties << prop
     end
 
     prop
   end
 
   def self.paramdoc(param)
     @paramhash[param].doc
   end
 
   # @return [Array<String>] Returns the parameter names
   def self.parameters
     return [] unless defined?(@parameters)
     @parameters.collect { |klass| klass.name }
   end
 
   # @return [Puppet::Parameter] Returns the parameter class associated with the given parameter name.
   def self.paramclass(name)
     @paramhash[name]
   end
 
   # @return [Puppet::Property] Returns the property class ??? associated with the given property name
   def self.propertybyname(name)
     @validproperties[name]
   end
 
   # Returns whether or not the given name is the name of a property, parameter or meta-parameter
   # @return [Boolean] true if the given attribute name is the name of an existing property, parameter or meta-parameter
   #
   def self.validattr?(name)
     name = name.intern
     return true if name == :name
     @validattrs ||= {}
 
     unless @validattrs.include?(name)
       @validattrs[name] = !!(self.validproperty?(name) or self.validparameter?(name) or self.metaparam?(name))
     end
 
     @validattrs[name]
   end
 
   # @return [Boolean] Returns true if the given name is the name of an existing property
   def self.validproperty?(name)
     name = name.intern
     @validproperties.include?(name) && @validproperties[name]
   end
 
   # @return [Array<Symbol>, {}] Returns a list of valid property names, or an empty hash if there are none.
   # @todo An empty hash is returned if there are no defined parameters (not an empty array). This looks like
   #   a bug.
   #
   def self.validproperties
     return {} unless defined?(@parameters)
 
     @validproperties.keys
   end
 
   # @return [Boolean] Returns true if the given name is the name of an existing parameter
   def self.validparameter?(name)
     raise Puppet::DevError, "Class #{self} has not defined parameters" unless defined?(@parameters)
     !!(@paramhash.include?(name) or @@metaparamhash.include?(name))
   end
 
   # (see validattr?)
   # @note see comment in code - how should this be documented? Are some of the other query methods deprecated?
   #   (or should be).
   # @comment This is a forward-compatibility method - it's the validity interface we'll use in Puppet::Resource.
   def self.valid_parameter?(name)
     validattr?(name)
   end
 
   # @return [Boolean] Returns true if the wanted state of the resoure is that it should be absent (i.e. to be deleted).
   def deleting?
     obj = @parameters[:ensure] and obj.should == :absent
   end
 
   # Creates a new property value holder for the resource if it is valid and does not already exist
   # @return [Boolean] true if a new parameter was added, false otherwise
   def add_property_parameter(prop_name)
     if self.class.validproperty?(prop_name) && !@parameters[prop_name]
       self.newattr(prop_name)
       return true
     end
     false
   end
 
   # @return [Symbol, Boolean] Returns the name of the namevar if there is only one or false otherwise.
   # @comment This is really convoluted and part of the support for multiple namevars (?).
   #   If there is only one namevar, the produced value is naturally this namevar, but if there are several?
   #   The logic caches the name of the namevar if it is a single name, but otherwise always
   #   calls key_attributes, and then caches the first if there was only one, otherwise it returns
   #   false and caches this (which is then subsequently returned as a cache hit).
   #
   def name_var
     return @name_var_cache unless @name_var_cache.nil?
     key_attributes = self.class.key_attributes
     @name_var_cache = (key_attributes.length == 1) && key_attributes.first
   end
 
   # Gets the 'should' (wanted state) value of a parameter or property by name.
   # To explicitly get the 'is' (current state) value use `o.is(:name)`, and to explicitly get the 'should' value
   # use `o.should(:name)`
   # @param name [String] the name of the attribute to obtain the 'should' value for.
   # @return [Object] 'should'/wanted value of the given attribute
   def [](name)
     name = name.intern
     fail("Invalid parameter #{name}(#{name.inspect})") unless self.class.validattr?(name)
 
     if name == :name && nv = name_var
       name = nv
     end
 
     if obj = @parameters[name]
       # Note that if this is a property, then the value is the "should" value,
       # not the current value.
       obj.value
     else
       return nil
     end
   end
 
   # Sets the 'should' (wanted state) value of a property, or the value of a parameter.
   # @return
   # @raise [Puppet::Error] if the setting of the value fails, or if the given name is nil.
   # @raise [Puppet::ResourceError] when the parameter validation raises Puppet::Error or
   #   ArgumentError
   def []=(name,value)
     name = name.intern
 
     fail("Invalid parameter #{name}") unless self.class.validattr?(name)
 
     if name == :name && nv = name_var
       name = nv
     end
     raise Puppet::Error.new("Got nil value for #{name}") if value.nil?
 
     property = self.newattr(name)
 
     if property
       begin
         # make sure the parameter doesn't have any errors
         property.value = value
       rescue Puppet::Error, ArgumentError => detail
         error = Puppet::ResourceError.new("Parameter #{name} failed on #{ref}: #{detail}")
         adderrorcontext(error, detail)
         raise error
       end
     end
 
     nil
   end
 
   # Removes a property from the object; useful in testing or in cleanup
   # when an error has been encountered
   # @todo Incomprehensible - the comment says "Remove a property", the code refers to @parameters, and
   #   the method parameter is called "attr" - What is it, property, parameter, both (i.e an attribute) or what?
   # @todo Don't know what the attr is (name or Property/Parameter?). Guessing it is a String name...
   # @todo Is it possible to delete a meta-parameter?
   # @todo What does delete mean? Is it deleted from the type or is its value state 'is'/'should' deleted?
   # @param attr [String] the attribute to delete from this object. WHAT IS THE TYPE?
   # @raise [Puppet::DecError] when an attempt is made to delete an attribute that does not exists.
   #
   def delete(attr)
     attr = attr.intern
     if @parameters.has_key?(attr)
       @parameters.delete(attr)
     else
       raise Puppet::DevError.new("Undefined attribute '#{attr}' in #{self}")
     end
   end
 
   # Iterates over the existing properties.
   # @todo what does this mean? As opposed to iterating over the "non existing properties" ??? Is it an
   #   iteration over those properties that have state? CONFUSING.
   # @yieldparam property [Puppet::Property] each property
   # @return [void]
   def eachproperty
     # properties is a private method
     properties.each { |property|
       yield property
     }
   end
 
   # Return the parameters, metaparams, and properties that have a value or were set by a default. Properties are
   # included since they are a subclass of parameter.
   # @return [Array<Puppet::Parameter>] Array of parameter objects ( or subclass thereof )
   def parameters_with_value
     self.class.allattrs.collect { |attr| parameter(attr) }.compact
   end
 
   # Iterates over all parameters with value currently set.
   # @yieldparam parameter [Puppet::Parameter] or a subclass thereof
   # @return [void]
   def eachparameter
     parameters_with_value.each { |parameter| yield parameter }
   end
 
   # Creates a transaction event.
   # Called by Transaction or by a property.
   # Merges the given options with the options `:resource`, `:file`, `:line`, and `:tags`, initialized from
   # values in this object. For possible options to pass (if any ????) see {Puppet::Transaction::Event}.
   # @todo Needs a better explanation "Why should I care who is calling this method?", What do I need to know
   #   about events and how they work? Where can I read about them?
   # @param options [Hash] options merged with a fixed set of options defined by this method, passed on to {Puppet::Transaction::Event}.
   # @return [Puppet::Transaction::Event] the created event
   def event(options = {})
     Puppet::Transaction::Event.new({:resource => self, :file => file, :line => line, :tags => tags}.merge(options))
   end
 
   # @return [Object, nil] Returns the 'should' (wanted state) value for a specified property, or nil if the
   #   given attribute name is not a property (i.e. if it is a parameter, meta-parameter, or does not exist).
   def should(name)
     name = name.intern
     (prop = @parameters[name] and prop.is_a?(Puppet::Property)) ? prop.should : nil
   end
 
   # Creates an instance to represent/manage the given attribute.
   # Requires either the attribute name or class as the first argument, then an optional hash of
   # attributes to set during initialization.
   # @todo The original comment is just wrong - the method does not accept a hash of options
   # @todo Detective work required; this method interacts with provider to ask if it supports a parameter of
   #   the given class. it then returns the parameter if it exists, otherwise creates a parameter
   #    with its :resource => self.
   # @overload newattr(name)
   #   @param name [String] Unclear what name is (probably a symbol) - Needs investigation.
   # @overload newattr(klass)
   #   @param klass [Class] a class supported as an attribute class - Needs clarification what that means.
   # @return [???] Probably returns a new instance of the class - Needs investigation.
   #
   def newattr(name)
     if name.is_a?(Class)
       klass = name
       name = klass.name
     end
 
     unless klass = self.class.attrclass(name)
       raise Puppet::Error, "Resource type #{self.class.name} does not support parameter #{name}"
     end
 
     if provider and ! provider.class.supports_parameter?(klass)
       missing = klass.required_features.find_all { |f| ! provider.class.feature?(f) }
       debug "Provider %s does not support features %s; not managing attribute %s" % [provider.class.name, missing.join(", "), name]
       return nil
     end
 
     return @parameters[name] if @parameters.include?(name)
 
     @parameters[name] = klass.new(:resource => self)
   end
 
   # Returns a string representation of the resource's containment path in
   # the catalog.
   # @return [String]
   def path
     @path ||= '/' + pathbuilder.join('/')
   end
 
   # Returns the value of this object's parameter given by name
   # @param name [String] the name of the parameter
   # @return [Object] the value
   def parameter(name)
     @parameters[name.to_sym]
   end
 
   # Returns a shallow copy of this object's hash of parameters.
   # @todo Add that this is not only "parameters", but also "properties" and "meta-parameters" ?
   # Changes to the contained parameters will have an effect on the parameters of this type, but changes to
   # the returned hash does not.
   # @return [Hash{String => Puppet:???Parameter}] a new hash being a shallow copy of the parameters map name to parameter
   def parameters
     @parameters.dup
   end
 
   # @return [Boolean] Returns whether the property given by name is defined or not.
   # @todo what does it mean to be defined?
   def propertydefined?(name)
     name = name.intern unless name.is_a? Symbol
     @parameters.include?(name)
   end
 
   # Returns a {Puppet::Property} instance by name.
   # To return the value, use 'resource[param]'
   # @todo LAK:NOTE(20081028) Since the 'parameter' method is now a superset of this method,
   #   this one should probably go away at some point. - Does this mean it should be deprecated ?
   # @return [Puppet::Property] the property with the given name, or nil if not a property or does not exist.
   def property(name)
     (obj = @parameters[name.intern] and obj.is_a?(Puppet::Property)) ? obj : nil
   end
 
   # @todo comment says "For any parameters or properties that have defaults and have not yet been
   #   set, set them now.  This method can be handed a list of attributes,
   #   and if so it will only set defaults for those attributes."
   # @todo Needs a better explanation, and investigation about the claim an array can be passed (it is passed
   #   to self.class.attrclass to produce a class on which a check is made if it has a method class :default (does
   #   not seem to support an array...
   # @return [void]
   #
   def set_default(attr)
     return unless klass = self.class.attrclass(attr)
     return unless klass.method_defined?(:default)
     return if @parameters.include?(klass.name)
 
     return unless parameter = newattr(klass.name)
 
     if value = parameter.default and ! value.nil?
       parameter.value = value
     else
       @parameters.delete(parameter.name)
     end
   end
 
   # @todo the comment says: "Convert our object to a hash.  This just includes properties."
   # @todo this is confused, again it is the @parameters instance variable that is consulted, and
   #   each value is copied - does it contain "properties" and "parameters" or both? Does it contain
   #   meta-parameters?
   #
   # @return [Hash{ ??? => ??? }] a hash of WHAT?. The hash is a shallow copy, any changes to the
   #  objects returned in this hash will be reflected in the original resource having these attributes.
   #
   def to_hash
     rethash = {}
 
     @parameters.each do |name, obj|
       rethash[name] = obj.value
     end
 
     rethash
   end
 
   # @return [String] the name of this object's class
   # @todo Would that be "file" for the "File" resource type? of "File" or something else?
   #
   def type
     self.class.name
   end
 
   # @todo Comment says "Return a specific value for an attribute.", as opposed to what "An upspecific value"???
   # @todo is this the 'is' or the 'should' value?
   # @todo why is the return restricted to things that respond to :value? (Only non structural basic data types
   #   supported?
   #
   # @return [Object, nil] the value of the attribute having the given name, or nil if the given name is not
   #   an attribute, or the referenced attribute does not respond to `:value`.
   def value(name)
     name = name.intern
 
     (obj = @parameters[name] and obj.respond_to?(:value)) ? obj.value : nil
   end
 
   # @todo What is this used for? Needs a better explanation.
   # @return [???] the version of the catalog or 0 if there is no catalog.
   def version
     return 0 unless catalog
     catalog.version
   end
 
   # @return [Array<Puppet::Property>] Returns all of the property objects, in the order specified in the
   #   class.
   # @todo "what does the 'order specified in the class' mean? The order the properties where added in the
   #   ruby file adding a new type with new properties?
   #
   def properties
     self.class.properties.collect { |prop| @parameters[prop.name] }.compact
   end
 
   # Returns true if the type's notion of name is the identity of a resource.
   # See the overview of this class for a longer explanation of the concept _isomorphism_.
   # Defaults to true.
   #
   # @return [Boolan] true, if this type's name is isomorphic with the object
   def self.isomorphic?
     if defined?(@isomorphic)
       return @isomorphic
     else
       return true
     end
   end
 
   # @todo check that this gets documentation (it is at the class level as well as instance).
   # (see isomorphic?)
   def isomorphic?
     self.class.isomorphic?
   end
 
   # Returns true if the instance is a managed instance.
   # A 'yes' here means that the instance was created from the language, vs. being created
   # in order resolve other questions, such as finding a package in a list.
   # @note An object that is managed always stays managed, but an object that is not managed
   #   may become managed later in its lifecycle.
   # @return [Boolean] true if the object is managed
   def managed?
     # Once an object is managed, it always stays managed; but an object
     # that is listed as unmanaged might become managed later in the process,
     # so we have to check that every time
     if @managed
       return @managed
     else
       @managed = false
       properties.each { |property|
         s = property.should
         if s and ! property.class.unmanaged
           @managed = true
           break
         end
       }
       return @managed
     end
   end
 
   ###############################
   # Code related to the container behaviour.
 
   # Returns true if the search should be done in depth-first order.
   # This implementation always returns false.
   # @todo What is this used for?
   #
   # @return [Boolean] true if the search should be done in depth first order.
   #
   def depthfirst?
     false
   end
 
   # Removes this object (FROM WHERE?)
   # @todo removes if from where?
   # @overload remove(rmdeps)
   #   @deprecated Use remove()
   #   @param rmdeps [Boolean] intended to indicate that all subscriptions should also be removed, ignored.
   # @overload remove()
   # @return [void]
   #
   def remove(rmdeps = true)
     # This is hackish (mmm, cut and paste), but it works for now, and it's
     # better than warnings.
     @parameters.each do |name, obj|
       obj.remove
     end
     @parameters.clear
 
     @parent = nil
 
     # Remove the reference to the provider.
     if self.provider
       @provider.clear
       @provider = nil
     end
   end
 
   ###############################
   # Code related to evaluating the resources.
 
   # Returns the ancestors - WHAT?
   # This implementation always returns an empty list.
   # @todo WHAT IS THIS ?
   # @return [Array<???>] returns a list of ancestors.
   def ancestors
     []
   end
 
+  # Lifecycle method for a resource. This is called during graph creation.
+  # It should perform any consistency checking of the catalog and raise a
+  # Puppet::Error if the transaction should be aborted.
+  #
+  # It differs from the validate method, since it is called later during
+  # initialization and can rely on self.catalog to have references to all
+  # resources that comprise the catalog.
+  #
+  # @see Puppet::Transaction#add_vertex
+  # @raises Puppet::Error
+  # @return void
+  # @abstract a resource type may implement this method to perform
+  #   validation checks that can query the complete catalog
+  def pre_run_check
+  end
+
   # Flushes the provider if supported by the provider, else no action.
   # This is called by the transaction.
   # @todo What does Flushing the provider mean? Why is it interesting to know that this is
   #   called by the transaction? (It is not explained anywhere what a transaction is).
   #
   # @return [???, nil] WHAT DOES IT RETURN? GUESS IS VOID
   def flush
     self.provider.flush if self.provider and self.provider.respond_to?(:flush)
   end
 
   # Returns true if all contained objects are in sync.
   # @todo "contained in what?" in the given "in" parameter?
   #
   # @todo deal with the comment _"FIXME I don't think this is used on the type instances any more,
   #   it's really only used for testing"_
   # @return [Boolean] true if in sync, false otherwise.
   #
   def insync?(is)
     insync = true
 
     if property = @parameters[:ensure]
       unless is.include? property
         raise Puppet::DevError,
           "The is value is not in the is array for '#{property.name}'"
       end
       ensureis = is[property]
       if property.safe_insync?(ensureis) and property.should == :absent
         return true
       end
     end
 
     properties.each { |property|
       unless is.include? property
         raise Puppet::DevError,
           "The is value is not in the is array for '#{property.name}'"
       end
 
       propis = is[property]
       unless property.safe_insync?(propis)
         property.debug("Not in sync: #{propis.inspect} vs #{property.should.inspect}")
         insync = false
       #else
       #    property.debug("In sync")
       end
     }
 
     #self.debug("#{self} sync status is #{insync}")
     insync
   end
 
   # Retrieves the current value of all contained properties.
   # Parameters and meta-parameters are not included in the result.
   # @todo As oposed to all non contained properties? How is this different than any of the other
   #   methods that also "gets" properties/parameters/etc. ?
   # @return [Puppet::Resource] array of all property values (mix of types)
   # @raise [fail???] if there is a provider and it is not suitable for the host this is evaluated for.
   def retrieve
     fail "Provider #{provider.class.name} is not functional on this host" if self.provider.is_a?(Puppet::Provider) and ! provider.class.suitable?
 
     result = Puppet::Resource.new(type, title)
 
     # Provide the name, so we know we'll always refer to a real thing
     result[:name] = self[:name] unless self[:name] == title
 
     if ensure_prop = property(:ensure) or (self.class.validattr?(:ensure) and ensure_prop = newattr(:ensure))
       result[:ensure] = ensure_state = ensure_prop.retrieve
     else
       ensure_state = nil
     end
 
     properties.each do |property|
       next if property.name == :ensure
       if ensure_state == :absent
         result[property] = :absent
       else
         result[property] = property.retrieve
       end
     end
 
     result
   end
 
   # Retrieve the current state of the system as a Puppet::Resource. For
   # the base Puppet::Type this does the same thing as #retrieve, but
   # specific types are free to implement #retrieve as returning a hash,
   # and this will call #retrieve and convert the hash to a resource.
   # This is used when determining when syncing a resource.
   #
   # @return [Puppet::Resource] A resource representing the current state
   #   of the system.
   #
   # @api private
   def retrieve_resource
     resource = retrieve
     resource = Resource.new(type, title, :parameters => resource) if resource.is_a? Hash
     resource
   end
 
   # Given the hash of current properties, should this resource be treated as if it
   # currently exists on the system. May need to be overridden by types that offer up
   # more than just :absent and :present.
   def present?(current_values)
     current_values[:ensure] != :absent
   end
 
   # Returns a hash of the current properties and their values.
   # If a resource is absent, its value is the symbol `:absent`
   # @return [Hash{Puppet::Property => Object}] mapping of property instance to its value
   #
   def currentpropvalues
     # It's important to use the 'properties' method here, as it follows the order
     # in which they're defined in the class.  It also guarantees that 'ensure'
     # is the first property, which is important for skipping 'retrieve' on
     # all the properties if the resource is absent.
     ensure_state = false
     return properties.inject({}) do | prophash, property|
       if property.name == :ensure
         ensure_state = property.retrieve
         prophash[property] = ensure_state
       else
         if ensure_state == :absent
           prophash[property] = :absent
         else
           prophash[property] = property.retrieve
         end
       end
       prophash
     end
   end
 
   # Returns the `noop` run mode status of this.
   # @return [Boolean] true if running in noop mode.
   def noop?
     # If we're not a host_config, we're almost certainly part of
     # Settings, and we want to ignore 'noop'
     return false if catalog and ! catalog.host_config?
 
     if defined?(@noop)
       @noop
     else
       Puppet[:noop]
     end
   end
 
   # (see #noop?)
   def noop
     noop?
   end
 
   # Retrieves all known instances.
   # @todo Retrieves them from where? Known to whom?
   # Either requires providers or must be overridden.
   # @raise [Puppet::DevError] when there are no providers and the implementation has not overridded this method.
   def self.instances
     raise Puppet::DevError, "#{self.name} has no providers and has not overridden 'instances'" if provider_hash.empty?
 
     # Put the default provider first, then the rest of the suitable providers.
     provider_instances = {}
     providers_by_source.collect do |provider|
       self.properties.find_all do |property|
         provider.supports_parameter?(property)
       end.collect do |property|
         property.name
       end
 
       provider.instances.collect do |instance|
         # We always want to use the "first" provider instance we find, unless the resource
         # is already managed and has a different provider set
         if other = provider_instances[instance.name]
           Puppet.debug "%s %s found in both %s and %s; skipping the %s version" %
             [self.name.to_s.capitalize, instance.name, other.class.name, instance.class.name, instance.class.name]
           next
         end
         provider_instances[instance.name] = instance
 
         result = new(:name => instance.name, :provider => instance)
         properties.each { |name| result.newattr(name) }
         result
       end
     end.flatten.compact
   end
 
   # Returns a list of one suitable provider per source, with the default provider first.
   # @todo Needs better explanation; what does "source" mean in this context?
   # @return [Array<Puppet::Provider>] list of providers
   #
   def self.providers_by_source
     # Put the default provider first (can be nil), then the rest of the suitable providers.
     sources = []
     [defaultprovider, suitableprovider].flatten.uniq.collect do |provider|
       next if provider.nil?
       next if sources.include?(provider.source)
 
       sources << provider.source
       provider
     end.compact
   end
 
   # Converts a simple hash into a Resource instance.
   # @todo as opposed to a complex hash? Other raised exceptions?
   # @param [Hash{Symbol, String => Object}] hash resource attribute to value map to initialize the created resource from
   # @return [Puppet::Resource] the resource created from the hash
   # @raise [Puppet::Error] if a title is missing in the given hash
   def self.hash2resource(hash)
     hash = hash.inject({}) { |result, ary| result[ary[0].to_sym] = ary[1]; result }
 
     title = hash.delete(:title)
     title ||= hash[:name]
     title ||= hash[key_attributes.first] if key_attributes.length == 1
 
     raise Puppet::Error, "Title or name must be provided" unless title
 
     # Now create our resource.
     resource = Puppet::Resource.new(self.name, title)
     resource.catalog = hash.delete(:catalog)
     resource.resource_type = self
 
     hash.each do |param, value|
       resource[param] = value
     end
     resource
   end
 
 
   # Returns an array of strings representing the containment heirarchy
   # (types/classes) that make up the path to the resource from the root
   # of the catalog.  This is mostly used for logging purposes.
   #
   # @api private
   def pathbuilder
     if p = parent
       [p.pathbuilder, self.ref].flatten
     else
       [self.ref]
     end
   end
 
   ###############################
   # Add all of the meta-parameters.
   newmetaparam(:noop) do
     desc "Whether to apply this resource in noop mode.
 
       When applying a resource in noop mode, Puppet will check whether it is in sync,
       like it does when running normally. However, if a resource attribute is not in
       the desired state (as declared in the catalog), Puppet will take no
       action, and will instead report the changes it _would_ have made. These
       simulated changes will appear in the report sent to the puppet master, or
       be shown on the console if running puppet agent or puppet apply in the
       foreground. The simulated changes will not send refresh events to any
       subscribing or notified resources, although Puppet will log that a refresh
       event _would_ have been sent.
 
       **Important note:**
       [The `noop` setting](http://docs.puppetlabs.com/references/latest/configuration.html#noop)
       allows you to globally enable or disable noop mode, but it will _not_ override
       the `noop` metaparameter on individual resources. That is, the value of the
       global `noop` setting will _only_ affect resources that do not have an explicit
       value set for their `noop` attribute."
 
     newvalues(:true, :false)
     munge do |value|
       case value
       when true, :true, "true"; @resource.noop = true
       when false, :false, "false"; @resource.noop = false
       end
     end
   end
 
   newmetaparam(:schedule) do
     desc "A schedule to govern when Puppet is allowed to manage this resource.
       The value of this metaparameter must be the `name` of a `schedule`
       resource. This means you must declare a schedule resource, then
       refer to it by name; see
       [the docs for the `schedule` type](http://docs.puppetlabs.com/references/latest/type.html#schedule)
       for more info.
 
           schedule { 'everyday':
             period => daily,
             range  => \"2-4\"
           }
 
           exec { \"/usr/bin/apt-get update\":
             schedule => 'everyday'
           }
 
       Note that you can declare the schedule resource anywhere in your
       manifests, as long as it ends up in the final compiled catalog."
   end
 
   newmetaparam(:audit) do
     desc "Marks a subset of this resource's unmanaged attributes for auditing. Accepts an
       attribute name, an array of attribute names, or `all`.
 
       Auditing a resource attribute has two effects: First, whenever a catalog
       is applied with puppet apply or puppet agent, Puppet will check whether
       that attribute of the resource has been modified, comparing its current
       value to the previous run; any change will be logged alongside any actions
       performed by Puppet while applying the catalog.
 
       Secondly, marking a resource attribute for auditing will include that
       attribute in inspection reports generated by puppet inspect; see the
       puppet inspect documentation for more details.
 
       Managed attributes for a resource can also be audited, but note that
       changes made by Puppet will be logged as additional modifications. (I.e.
       if a user manually edits a file whose contents are audited and managed,
       puppet agent's next two runs will both log an audit notice: the first run
       will log the user's edit and then revert the file to the desired state,
       and the second run will log the edit made by Puppet.)"
 
     validate do |list|
       list = Array(list).collect {|p| p.to_sym}
       unless list == [:all]
         list.each do |param|
           next if @resource.class.validattr?(param)
           fail "Cannot audit #{param}: not a valid attribute for #{resource}"
         end
       end
     end
 
     munge do |args|
       properties_to_audit(args).each do |param|
         next unless resource.class.validproperty?(param)
         resource.newattr(param)
       end
     end
 
     def all_properties
       resource.class.properties.find_all do |property|
         resource.provider.nil? or resource.provider.class.supports_parameter?(property)
       end.collect do |property|
         property.name
       end
     end
 
     def properties_to_audit(list)
       if !list.kind_of?(Array) && list.to_sym == :all
         list = all_properties
       else
         list = Array(list).collect { |p| p.to_sym }
       end
     end
   end
 
   newmetaparam(:loglevel) do
     desc "Sets the level that information will be logged.
       The log levels have the biggest impact when logs are sent to
       syslog (which is currently the default)."
     defaultto :notice
 
     newvalues(*Puppet::Util::Log.levels)
     newvalues(:verbose)
 
     munge do |loglevel|
       val = super(loglevel)
       if val == :verbose
         val = :info
       end
       val
     end
   end
 
   newmetaparam(:alias) do
     desc %q{Creates an alias for the resource.  Puppet uses this internally when you
       provide a symbolic title and an explicit namevar value:
 
           file { 'sshdconfig':
             path => $operatingsystem ? {
               solaris => '/usr/local/etc/ssh/sshd_config',
               default => '/etc/ssh/sshd_config',
             },
             source => '...'
           }
 
           service { 'sshd':
             subscribe => File['sshdconfig'],
           }
 
       When you use this feature, the parser sets `sshdconfig` as the title,
       and the library sets that as an alias for the file so the dependency
       lookup in `Service['sshd']` works.  You can use this metaparameter yourself,
       but note that aliases generally only work for creating relationships; anything
       else that refers to an existing resource (such as amending or overriding
       resource attributes in an inherited class) must use the resource's exact
       title. For example, the following code will not work:
 
           file { '/etc/ssh/sshd_config':
             owner => root,
             group => root,
             alias => 'sshdconfig',
           }
 
           File['sshdconfig'] {
             mode => 644,
           }
 
       There's no way here for the Puppet parser to know that these two stanzas
       should be affecting the same file.
 
       }
 
     munge do |aliases|
       aliases = [aliases] unless aliases.is_a?(Array)
 
       raise(ArgumentError, "Cannot add aliases without a catalog") unless @resource.catalog
 
       aliases.each do |other|
         if obj = @resource.catalog.resource(@resource.class.name, other)
           unless obj.object_id == @resource.object_id
             self.fail("#{@resource.title} can not create alias #{other}: object already exists")
           end
           next
         end
 
         # Newschool, add it to the catalog.
         @resource.catalog.alias(@resource, other)
       end
     end
   end
 
   newmetaparam(:tag) do
     desc "Add the specified tags to the associated resource.  While all resources
       are automatically tagged with as much information as possible
       (e.g., each class and definition containing the resource), it can
       be useful to add your own tags to a given resource.
 
       Multiple tags can be specified as an array:
 
           file {'/etc/hosts':
             ensure => file,
             source => 'puppet:///modules/site/hosts',
             mode   => 0644,
             tag    => ['bootstrap', 'minimumrun', 'mediumrun'],
           }
 
       Tags are useful for things like applying a subset of a host's configuration
       with [the `tags` setting](/references/latest/configuration.html#tags)
       (e.g. `puppet agent --test --tags bootstrap`) or filtering alerts with
       [the `tagmail` report processor](http://docs.puppetlabs.com/references/latest/report.html#tagmail)."
 
     munge do |tags|
       tags = [tags] unless tags.is_a? Array
 
       tags.each do |tag|
         @resource.tag(tag)
       end
     end
   end
 
   # RelationshipMetaparam is an implementation supporting the meta-parameters `:require`, `:subscribe`,
   # `:notify`, and `:before`.
   #
   #
   class RelationshipMetaparam < Puppet::Parameter
     class << self
       attr_accessor :direction, :events, :callback, :subclasses
     end
 
     @subclasses = []
 
     def self.inherited(sub)
       @subclasses << sub
     end
 
     # @return [Array<Puppet::Resource>] turns attribute value(s) into list of resources
     def munge(references)
       references = [references] unless references.is_a?(Array)
       references.collect do |ref|
         if ref.is_a?(Puppet::Resource)
           ref
         else
           Puppet::Resource.new(ref)
         end
       end
     end
 
     # Checks each reference to assert that what it references exists in the catalog.
     #
     # @raise [???fail] if the referenced resource can not be found
     # @return [void]
     def validate_relationship
       @value.each do |ref|
         unless @resource.catalog.resource(ref.to_s)
           description = self.class.direction == :in ? "dependency" : "dependent"
           fail ResourceError, "Could not find #{description} #{ref} for #{resource.ref}"
         end
       end
     end
 
     # Creates edges for all relationships.
     # The `:in` relationships are specified by the event-receivers, and `:out`
     # relationships are specified by the event generator.
     # @todo references to "event-receivers" and "event generator" means in this context - are those just
     #   the resources at the two ends of the relationship?
     # This way 'source' and 'target' are consistent terms in both edges
     # and events, i.e. an event targets edges whose source matches
     # the event's source. The direction of the relationship determines
     # which resource is applied first and which resource is considered
     # to be the event generator.
     # @return [Array<Puppet::Relationship>]
     # @raise [???fail] when a reference can not be resolved
     #
     def to_edges
       @value.collect do |reference|
         reference.catalog = resource.catalog
 
         # Either of the two retrieval attempts could have returned
         # nil.
         unless related_resource = reference.resolve
           self.fail "Could not retrieve dependency '#{reference}' of #{@resource.ref}"
         end
 
         # Are we requiring them, or vice versa?  See the method docs
         # for futher info on this.
         if self.class.direction == :in
           source = related_resource
           target = @resource
         else
           source = @resource
           target = related_resource
         end
 
         if method = self.class.callback
           subargs = {
             :event => self.class.events,
             :callback => method
           }
           self.debug("subscribes to #{related_resource.ref}")
         else
           # If there's no callback, there's no point in even adding
           # a label.
           subargs = nil
           self.debug("requires #{related_resource.ref}")
         end
 
         Puppet::Relationship.new(source, target, subargs)
       end
     end
   end
 
   # @todo document this, have no clue what this does... it retuns "RelationshipMetaparam.subclasses"
   #
   def self.relationship_params
     RelationshipMetaparam.subclasses
   end
 
 
   # Note that the order in which the relationships params is defined
   # matters.  The labelled params (notify and subcribe) must be later,
   # so that if both params are used, those ones win.  It's a hackish
   # solution, but it works.
 
   newmetaparam(:require, :parent => RelationshipMetaparam, :attributes => {:direction => :in, :events => :NONE}) do
     desc "One or more resources that this resource depends on, expressed as
       [resource references](http://docs.puppetlabs.com/puppet/latest/reference/lang_datatypes.html#resource-references).
       Multiple resources can be specified as an array of references. When this
       attribute is present:
 
       * The required resource(s) will be applied **before** this resource.
 
       This is one of the four relationship metaparameters, along with
       `before`, `notify`, and `subscribe`. For more context, including the
       alternate chaining arrow (`->` and `~>`) syntax, see
       [the language page on relationships](http://docs.puppetlabs.com/puppet/latest/reference/lang_relationships.html)."
   end
 
   newmetaparam(:subscribe, :parent => RelationshipMetaparam, :attributes => {:direction => :in, :events => :ALL_EVENTS, :callback => :refresh}) do
     desc "One or more resources that this resource depends on, expressed as
       [resource references](http://docs.puppetlabs.com/puppet/latest/reference/lang_datatypes.html#resource-references).
       Multiple resources can be specified as an array of references. When this
       attribute is present:
 
       * The subscribed resource(s) will be applied _before_ this resource.
       * If Puppet makes changes to any of the subscribed resources, it will cause
         this resource to _refresh._ (Refresh behavior varies by resource
         type: services will restart, mounts will unmount and re-mount, etc. Not
         all types can refresh.)
 
       This is one of the four relationship metaparameters, along with
       `before`, `require`, and `notify`. For more context, including the
       alternate chaining arrow (`->` and `~>`) syntax, see
       [the language page on relationships](http://docs.puppetlabs.com/puppet/latest/reference/lang_relationships.html)."
   end
 
   newmetaparam(:before, :parent => RelationshipMetaparam, :attributes => {:direction => :out, :events => :NONE}) do
     desc "One or more resources that depend on this resource, expressed as
       [resource references](http://docs.puppetlabs.com/puppet/latest/reference/lang_datatypes.html#resource-references).
       Multiple resources can be specified as an array of references. When this
       attribute is present:
 
       * This resource will be applied _before_ the dependent resource(s).
 
       This is one of the four relationship metaparameters, along with
       `require`, `notify`, and `subscribe`. For more context, including the
       alternate chaining arrow (`->` and `~>`) syntax, see
       [the language page on relationships](http://docs.puppetlabs.com/puppet/latest/reference/lang_relationships.html)."
   end
 
   newmetaparam(:notify, :parent => RelationshipMetaparam, :attributes => {:direction => :out, :events => :ALL_EVENTS, :callback => :refresh}) do
     desc "One or more resources that depend on this resource, expressed as
       [resource references](http://docs.puppetlabs.com/puppet/latest/reference/lang_datatypes.html#resource-references).
       Multiple resources can be specified as an array of references. When this
       attribute is present:
 
       * This resource will be applied _before_ the notified resource(s).
       * If Puppet makes changes to this resource, it will cause all of the
         notified resources to _refresh._ (Refresh behavior varies by resource
         type: services will restart, mounts will unmount and re-mount, etc. Not
         all types can refresh.)
 
       This is one of the four relationship metaparameters, along with
       `before`, `require`, and `subscribe`. For more context, including the
       alternate chaining arrow (`->` and `~>`) syntax, see
       [the language page on relationships](http://docs.puppetlabs.com/puppet/latest/reference/lang_relationships.html)."
   end
 
   newmetaparam(:stage) do
     desc %{Which run stage this class should reside in.
 
       **Note: This metaparameter can only be used on classes,** and only when
       declaring them with the resource-like syntax. It cannot be used on normal
       resources or on classes declared with `include`.
 
       By default, all classes are declared in the `main` stage. To assign a class
       to a different stage, you must:
 
       * Declare the new stage as a [`stage` resource](http://docs.puppetlabs.com/references/latest/type.html#stage).
       * Declare an order relationship between the new stage and the `main` stage.
       * Use the resource-like syntax to declare the class, and set the `stage`
         metaparameter to the name of the desired stage.
 
       For example:
 
           stage { 'pre':
             before => Stage['main'],
           }
 
           class { 'apt-updates':
             stage => 'pre',
           }
     }
   end
 
   ###############################
   # All of the provider plumbing for the resource types.
   require 'puppet/provider'
   require 'puppet/util/provider_features'
 
   # Add the feature handling module.
   extend Puppet::Util::ProviderFeatures
 
   # The provider that has been selected for the instance of the resource type.
   # @return [Puppet::Provider,nil] the selected provider or nil, if none has been selected
   #
   attr_reader :provider
 
   # the Type class attribute accessors
   class << self
     # The loader of providers to use when loading providers from disk.
     # Although it looks like this attribute provides a way to operate with different loaders of
     # providers that is not the case; the attribute is written when a new type is created,
     # and should not be changed thereafter.
     # @api private
     #
     attr_accessor :providerloader
 
     # @todo Don't know if this is a name, or a reference to a Provider instance (now marked up as an instance
     #   of Provider.
     # @return [Puppet::Provider, nil] The default provider for this type, or nil if non is defines
     #
     attr_writer :defaultprovider
   end
 
   # The default provider, or the most suitable provider if no default provider was set.
   # @note a warning will be issued if no default provider has been configured and a search for the most
   #   suitable provider returns more than one equally suitable provider.
   # @return [Puppet::Provider, nil] the default or most suitable provider, or nil if no provider was found
   #
   def self.defaultprovider
     return @defaultprovider if @defaultprovider
 
     suitable = suitableprovider
 
     # Find which providers are a default for this system.
     defaults = suitable.find_all { |provider| provider.default? }
 
     # If we don't have any default we use suitable providers
     defaults = suitable if defaults.empty?
     max = defaults.collect { |provider| provider.specificity }.max
     defaults = defaults.find_all { |provider| provider.specificity == max }
 
     if defaults.length > 1
       Puppet.warning(
         "Found multiple default providers for #{self.name}: #{defaults.collect { |i| i.name.to_s }.join(", ")}; using #{defaults[0].name}"
       )
     end
 
     @defaultprovider = defaults.shift unless defaults.empty?
   end
 
   # @return [Hash{??? => Puppet::Provider}] Returns a hash of WHAT EXACTLY for the given type
   # @todo what goes into this hash?
   def self.provider_hash_by_type(type)
     @provider_hashes ||= {}
     @provider_hashes[type] ||= {}
   end
 
   # @return [Hash{ ??? => Puppet::Provider}] Returns a hash of WHAT EXACTLY for this type.
   # @see provider_hash_by_type method to get the same for some other type
   def self.provider_hash
     Puppet::Type.provider_hash_by_type(self.name)
   end
 
   # Returns the provider having the given name.
   # This will load a provider if it is not already loaded. The returned provider is the first found provider
   # having the given name, where "first found" semantics is defined by the {providerloader} in use.
   #
   # @param name [String] the name of the provider to get
   # @return [Puppet::Provider, nil] the found provider, or nil if no provider of the given name was found
   #
   def self.provider(name)
     name = name.intern
 
     # If we don't have it yet, try loading it.
     @providerloader.load(name) unless provider_hash.has_key?(name)
     provider_hash[name]
   end
 
   # Returns a list of loaded providers by name.
   # This method will not load/search for available providers.
   # @return [Array<String>] list of loaded provider names
   #
   def self.providers
     provider_hash.keys
   end
 
   # Returns true if the given name is a reference to a provider and if this is a suitable provider for
   # this type.
   # @todo How does the provider know if it is suitable for the type? Is it just suitable for the platform/
   #   environment where this method is executing?
   # @param name [String] the name of the provider for which validity is checked
   # @return [Boolean] true if the given name references a provider that is suitable
   #
   def self.validprovider?(name)
     name = name.intern
 
     (provider_hash.has_key?(name) && provider_hash[name].suitable?)
   end
 
   # Creates a new provider of a type.
   # This method must be called directly on the type that it's implementing.
   # @todo Fix Confusing Explanations!
   #   Is this a new provider of a Type (metatype), or a provider of an instance of Type (a resource), or
   #   a Provider (the implementation of a Type's behavior). CONFUSED. It calls magically named methods like
   #   "providify" ...
   # @param name [String, Symbol] the name of the WHAT? provider? type?
   # @param options [Hash{Symbol => Object}] a hash of options, used by this method, and passed on to {#genclass}, (see
   #   it for additional options to pass).
   # @option options [Puppet::Provider] :parent the parent provider (what is this?)
   # @option options [Puppet::Type] :resource_type the resource type, defaults to this type if unspecified
   # @return [Puppet::Provider] a provider ???
   # @raise [Puppet::DevError] when the parent provider could not be found.
   #
   def self.provide(name, options = {}, &block)
     name = name.intern
 
     if unprovide(name)
       Puppet.debug "Reloading #{name} #{self.name} provider"
     end
 
     parent = if pname = options[:parent]
       options.delete(:parent)
       if pname.is_a? Class
         pname
       else
         if provider = self.provider(pname)
           provider
         else
           raise Puppet::DevError,
             "Could not find parent provider #{pname} of #{name}"
         end
       end
     else
       Puppet::Provider
     end
 
     options[:resource_type] ||= self
 
     self.providify
 
     provider = genclass(
       name,
       :parent     => parent,
       :hash       => provider_hash,
       :prefix     => "Provider",
       :block      => block,
       :include    => feature_module,
       :extend     => feature_module,
       :attributes => options
     )
 
     provider
   end
 
   # Ensures there is a `:provider` parameter defined.
   # Should only be called if there are providers.
   # @return [void]
   def self.providify
     return if @paramhash.has_key? :provider
 
     newparam(:provider) do
       # We're using a hacky way to get the name of our type, since there doesn't
       # seem to be a correct way to introspect this at the time this code is run.
       # We expect that the class in which this code is executed will be something
       # like Puppet::Type::Ssh_authorized_key::ParameterProvider.
       desc <<-EOT
         The specific backend to use for this `#{self.to_s.split('::')[2].downcase}`
         resource. You will seldom need to specify this --- Puppet will usually
         discover the appropriate provider for your platform.
       EOT
 
       # This is so we can refer back to the type to get a list of
       # providers for documentation.
       class << self
         # The reference to a parent type for the parameter `:provider` used to get a list of
         # providers for documentation purposes.
         #
         attr_accessor :parenttype
       end
 
       # Provides the ability to add documentation to a provider.
       #
       def self.doc
         # Since we're mixing @doc with text from other sources, we must normalize
         # its indentation with scrub. But we don't need to manually scrub the
         # provider's doc string, since markdown_definitionlist sanitizes its inputs.
         scrub(@doc) + "Available providers are:\n\n" + parenttype.providers.sort { |a,b|
           a.to_s <=> b.to_s
         }.collect { |i|
           markdown_definitionlist( i, scrub(parenttype().provider(i).doc) )
         }.join
       end
 
       # @todo this does what? where and how?
       # @return [String] the name of the provider
       defaultto {
         prov = @resource.class.defaultprovider
         prov.name if prov
       }
 
       validate do |provider_class|
         provider_class = provider_class[0] if provider_class.is_a? Array
         provider_class = provider_class.class.name if provider_class.is_a?(Puppet::Provider)
 
         unless @resource.class.provider(provider_class)
           raise ArgumentError, "Invalid #{@resource.class.name} provider '#{provider_class}'"
         end
       end
 
       munge do |provider|
         provider = provider[0] if provider.is_a? Array
         provider = provider.intern if provider.is_a? String
         @resource.provider = provider
 
         if provider.is_a?(Puppet::Provider)
           provider.class.name
         else
           provider
         end
       end
     end.parenttype = self
   end
 
   # @todo this needs a better explanation
   # Removes the implementation class of a given provider.
   # @return [Object] returns what {Puppet::Util::ClassGen#rmclass} returns
   def self.unprovide(name)
     if @defaultprovider and @defaultprovider.name == name
       @defaultprovider = nil
     end
 
     rmclass(name, :hash => provider_hash, :prefix => "Provider")
   end
 
   # Returns a list of suitable providers for the given type.
   # A call to this method will load all providers if not already loaded and ask each if it is
   # suitable - those that are are included in the result.
   # @note This method also does some special processing which rejects a provider named `:fake` (for testing purposes).
   # @return [Array<Puppet::Provider>] Returns an array of all suitable providers.
   #
   def self.suitableprovider
     providerloader.loadall if provider_hash.empty?
     provider_hash.find_all { |name, provider|
       provider.suitable?
     }.collect { |name, provider|
       provider
     }.reject { |p| p.name == :fake } # For testing
   end
 
   # @return [Boolean] Returns true if this is something else than a `:provider`, or if it
   #   is a provider and it is suitable, or if there is a default provider. Otherwise, false is returned.
   #
   def suitable?
     # If we don't use providers, then we consider it suitable.
     return true unless self.class.paramclass(:provider)
 
     # We have a provider and it is suitable.
     return true if provider && provider.class.suitable?
 
     # We're using the default provider and there is one.
     if !provider and self.class.defaultprovider
       self.provider = self.class.defaultprovider.name
       return true
     end
 
     # We specified an unsuitable provider, or there isn't any suitable
     # provider.
     false
   end
 
   # Sets the provider to the given provider/name.
   # @overload provider=(name)
   #   Sets the provider to the result of resolving the name to an instance of Provider.
   #   @param name [String] the name of the provider
   # @overload provider=(provider)
   #   Sets the provider to the given instances of Provider.
   #   @param provider [Puppet::Provider] the provider to set
   # @return [Puppet::Provider] the provider set
   # @raise [ArgumentError] if the provider could not be found/resolved.
   #
   def provider=(name)
     if name.is_a?(Puppet::Provider)
       @provider = name
       @provider.resource = self
     elsif klass = self.class.provider(name)
       @provider = klass.new(self)
     else
       raise ArgumentError, "Could not find #{name} provider of #{self.class.name}"
     end
   end
 
   ###############################
   # All of the relationship code.
 
   # Adds a block producing a single name (or list of names) of the given resource type name to autorequire.
   # @example Autorequire the files File['foo', 'bar']
   #   autorequire( 'file', {|| ['foo', 'bar'] })
   #
   # @todo original = _"Specify a block for generating a list of objects to autorequire.
   #   This makes it so that you don't have to manually specify things that you clearly require."_
   # @param name [String] the name of a type of which one or several resources should be autorequired e.g. "file"
   # @yield [ ] a block returning list of names of given type to auto require
   # @yieldreturn [String, Array<String>] one or several resource names for the named type
   # @return [void]
   # @dsl type
   # @api public
   #
   def self.autorequire(name, &block)
     @autorequires ||= {}
     @autorequires[name] = block
   end
 
   # Provides iteration over added auto-requirements (see {autorequire}).
   # @yieldparam type [String] the name of the type to autoriquire an instance of
   # @yieldparam block [Proc] a block producing one or several dependencies to auto require (see {autorequire}).
   # @yieldreturn [void]
   # @return [void]
   def self.eachautorequire
     @autorequires ||= {}
     @autorequires.each { |type, block|
       yield(type, block)
     }
   end
 
   # Adds dependencies to the catalog from added autorequirements.
   # See {autorequire} for how to add an auto-requirement.
   # @todo needs details - see the param rel_catalog, and type of this param
   # @param rel_catalog [Puppet::Resource::Catalog, nil] the catalog to
   #   add dependencies to. Defaults to the current catalog (set when the
   #   type instance was added to a catalog)
   # @raise [Puppet::DevError] if there is no catalog
   #
   def autorequire(rel_catalog = nil)
     rel_catalog ||= catalog
     raise(Puppet::DevError, "You cannot add relationships without a catalog") unless rel_catalog
 
     reqs = []
     self.class.eachautorequire { |type, block|
       # Ignore any types we can't find, although that would be a bit odd.
       next unless Puppet::Type.type(type)
 
       # Retrieve the list of names from the block.
       next unless list = self.instance_eval(&block)
       list = [list] unless list.is_a?(Array)
 
       # Collect the current prereqs
       list.each { |dep|
         # Support them passing objects directly, to save some effort.
         unless dep.is_a? Puppet::Type
           # Skip autorequires that we aren't managing
           unless dep = rel_catalog.resource(type, dep)
             next
           end
         end
 
         reqs << Puppet::Relationship.new(dep, self)
       }
     }
 
     reqs
   end
 
   # Builds the dependencies associated with an individual object.
   # @todo Which object is the "individual object", as opposed to "object as a group?" or should it simply
   #   be "this object" as in "this resource" ?
   # @todo Does this method "build dependencies" or "build what it depends on" ... CONFUSING
   #
   # @return [Array<???>] list of WHAT? resources? edges?
   def builddepends
     # Handle the requires
     self.class.relationship_params.collect do |klass|
       if param = @parameters[klass.name]
         param.to_edges
       end
     end.flatten.reject { |r| r.nil? }
   end
 
   # Sets the initial list of tags...
   # @todo The initial list of tags, that ... that what?
   # @return [void] ???
   def tags=(list)
     tag(self.class.name)
     tag(*list)
   end
 
   # @comment - these two comments were floating around here, and turned up as documentation
   #  for the attribute "title", much to my surprise and amusement. Clearly these comments
   #  are orphaned ... I think they can just be removed as what they say should be covered
   #  by the now added yardoc. <irony>(Yo! to quote some of the other actual awsome specific comments applicable
   #  to objects called from elsewhere, or not. ;-)</irony>
   #
   # @comment Types (which map to resources in the languages) are entirely composed of
   #   attribute value pairs.  Generally, Puppet calls any of these things an
   #   'attribute', but these attributes always take one of three specific
   #   forms:  parameters, metaparams, or properties.
 
   # @comment In naming methods, I have tried to consistently name the method so
   #   that it is clear whether it operates on all attributes (thus has 'attr' in
   #   the method name, or whether it operates on a specific type of attributes.
 
   # The title attribute of WHAT ???
   # @todo Figure out what this is the title attribute of (it appears on line 1926 currently).
   # @return [String] the title
   attr_writer :title
 
   # The noop attribute of WHAT ??? does WHAT???
   # @todo Figure out what this is the noop attribute of (it appears on line 1931 currently).
   # @return [???] the noop WHAT ??? (mode? if so of what, or noop for an instance of the type, or for all
   #   instances of a type, or for what???
   #
   attr_writer :noop
 
   include Enumerable
 
   # class methods dealing with Type management
 
   public
 
   # The Type class attribute accessors
   class << self
     # @return [String] the name of the resource type; e.g., "File"
     #
     attr_reader :name
 
     # @return [Boolean] true if the type should send itself a refresh event on change.
     #
     attr_accessor :self_refresh
     include Enumerable, Puppet::Util::ClassGen
     include Puppet::MetaType::Manager
 
     include Puppet::Util
     include Puppet::Util::Logging
   end
 
   # Initializes all of the variables that must be initialized for each subclass.
   # @todo Does the explanation make sense?
   # @return [void]
   def self.initvars
     # all of the instances of this class
     @objects = Hash.new
     @aliases = Hash.new
 
     @defaults = {}
 
     @parameters ||= []
 
     @validproperties = {}
     @properties = []
     @parameters = []
     @paramhash = {}
 
     @paramdoc = Hash.new { |hash,key|
       key = key.intern if key.is_a?(String)
       if hash.include?(key)
         hash[key]
       else
         "Param Documentation for #{key} not found"
       end
     }
 
     @doc ||= ""
 
   end
 
   # Returns the name of this type (if specified) or the parent type #to_s.
   # The returned name is on the form "Puppet::Type::<name>", where the first letter of name is
   # capitalized.
   # @return [String] the fully qualified name Puppet::Type::<name> where the first letter of name is captialized
   #
   def self.to_s
     if defined?(@name)
       "Puppet::Type::#{@name.to_s.capitalize}"
     else
       super
     end
   end
 
   # Creates a `validate` method that is used to validate a resource before it is operated on.
   # The validation should raise exceptions if the validation finds errors. (It is not recommended to
   # issue warnings as this typically just ends up in a logfile - you should fail if a validation fails).
   # The easiest way to raise an appropriate exception is to call the method {Puppet::Util::Errors.fail} with
   # the message as an argument.
   #
   # @yield [ ] a required block called with self set to the instance of a Type class representing a resource.
   # @return [void]
   # @dsl type
   # @api public
   #
   def self.validate(&block)
     define_method(:validate, &block)
   end
 
   # @return [String] The file from which this type originates from
   attr_accessor :file
 
   # @return [Integer] The line in {#file} from which this type originates from
   attr_accessor :line
 
   # @todo what does this mean "this resource" (sounds like this if for an instance of the type, not the meta Type),
   #   but not sure if this is about the catalog where the meta Type is included)
   # @return [??? TODO] The catalog that this resource is stored in.
   attr_accessor :catalog
 
   # @return [Boolean] Flag indicating if this type is exported
   attr_accessor :exported
 
   # @return [Boolean] Flag indicating if the type is virtual (it should not be).
   attr_accessor :virtual
 
   # Creates a log entry with the given message at the log level specified by the parameter `loglevel`
   # @return [void]
   #
   def log(msg)
 
     Puppet::Util::Log.create(
 
       :level => @parameters[:loglevel].value,
       :message => msg,
 
       :source => self
     )
   end
 
 
   # instance methods related to instance intrinsics
   # e.g., initialize and name
 
   public
 
   # @return [Hash] hash of parameters originally defined
   # @api private
   attr_reader :original_parameters
 
   # Creates an instance of Type from a hash or a {Puppet::Resource}.
   # @todo Unclear if this is a new Type or a new instance of a given type (the initialization ends
   #   with calling validate - which seems like validation of an instance of a given type, not a new
   #   meta type.
   #
   # @todo Explain what the Hash and Resource are. There seems to be two different types of
   #   resources; one that causes the title to be set to resource.title, and one that
   #   causes the title to be resource.ref ("for components") - what is a component?
   #
   # @overload initialize(hash)
   #   @param [Hash] hash
   #   @raise [Puppet::ResourceError] when the type validation raises
   #     Puppet::Error or ArgumentError
   # @overload initialize(resource)
   #   @param resource [Puppet:Resource]
   #   @raise [Puppet::ResourceError] when the type validation raises
   #     Puppet::Error or ArgumentError
   #
   def initialize(resource)
     resource = self.class.hash2resource(resource) unless resource.is_a?(Puppet::Resource)
 
     # The list of parameter/property instances.
     @parameters = {}
 
     # Set the title first, so any failures print correctly.
     if resource.type.to_s.downcase.to_sym == self.class.name
       self.title = resource.title
     else
       # This should only ever happen for components
       self.title = resource.ref
     end
 
     [:file, :line, :catalog, :exported, :virtual].each do |getter|
       setter = getter.to_s + "="
       if val = resource.send(getter)
         self.send(setter, val)
       end
     end
 
     @tags = resource.tags
 
     @original_parameters = resource.to_hash
 
     set_name(@original_parameters)
 
     set_default(:provider)
 
     set_parameters(@original_parameters)
 
     begin
       self.validate if self.respond_to?(:validate)
     rescue Puppet::Error, ArgumentError => detail
       error = Puppet::ResourceError.new("Validation of #{ref} failed: #{detail}")
       adderrorcontext(error, detail)
       raise error
     end
   end
 
   private
 
   # Sets the name of the resource from a hash containing a mapping of `name_var` to value.
   # Sets the value of the property/parameter appointed by the `name_var` (if it is defined). The value set is
   # given by the corresponding entry in the given hash - e.g. if name_var appoints the name `:path` the value
   # of `:path` is set to the value at the key `:path` in the given hash. As a side effect this key/value is then
   # removed from the given hash.
   #
   # @note This method mutates the given hash by removing the entry with a key equal to the value
   #   returned from name_var!
   # @param hash [Hash] a hash of what
   # @return [void]
   def set_name(hash)
     self[name_var] = hash.delete(name_var) if name_var
   end
 
   # Sets parameters from the given hash.
   # Values are set in _attribute order_ i.e. higher priority attributes before others, otherwise in
   # the order they were specified (as opposed to just setting them in the order they happen to appear in
   # when iterating over the given hash).
   #
   # Attributes that are not included in the given hash are set to their default value.
   #
   # @todo Is this description accurate? Is "ensure" an example of such a higher priority attribute?
   # @return [void]
   # @raise [Puppet::DevError] when impossible to set the value due to some problem
   # @raise [ArgumentError, TypeError, Puppet::Error] when faulty arguments have been passed
   #
   def set_parameters(hash)
     # Use the order provided by allattrs, but add in any
     # extra attributes from the resource so we get failures
     # on invalid attributes.
     no_values = []
     (self.class.allattrs + hash.keys).uniq.each do |attr|
       begin
         # Set any defaults immediately.  This is mostly done so
         # that the default provider is available for any other
         # property validation.
         if hash.has_key?(attr)
           self[attr] = hash[attr]
         else
           no_values << attr
         end
       rescue ArgumentError, Puppet::Error, TypeError
         raise
       rescue => detail
         error = Puppet::DevError.new( "Could not set #{attr} on #{self.class.name}: #{detail}")
         error.set_backtrace(detail.backtrace)
         raise error
       end
     end
     no_values.each do |attr|
       set_default(attr)
     end
   end
 
   public
 
   # Finishes any outstanding processing.
   # This method should be called as a final step in setup,
   # to allow the parameters that have associated auto-require needs to be processed.
   #
   # @todo what is the expected sequence here - who is responsible for calling this? When?
   #   Is the returned type correct?
   # @return [Array<Puppet::Parameter>] the validated list/set of attributes
   #
   def finish
     # Call post_compile hook on every parameter that implements it. This includes all subclasses
     # of parameter including, but not limited to, regular parameters, metaparameters, relationship
     # parameters, and properties.
     eachparameter do |parameter|
       parameter.post_compile if parameter.respond_to? :post_compile
     end
 
     # Make sure all of our relationships are valid.  Again, must be done
     # when the entire catalog is instantiated.
     self.class.relationship_params.collect do |klass|
       if param = @parameters[klass.name]
         param.validate_relationship
       end
     end.flatten.reject { |r| r.nil? }
   end
 
   # @comment For now, leave the 'name' method functioning like it used to.  Once 'title'
   #   works everywhere, I'll switch it.
   # Returns the resource's name
   # @todo There is a comment in source that this is not quite the same as ':title' and that a switch should
   #   be made...
   # @return [String] the name of a resource
   def name
     self[:name]
   end
 
   # Returns the parent of this in the catalog.  In case of an erroneous catalog
   # where multiple parents have been produced, the first found (non
   # deterministic) parent is returned.
   # @return [Puppet::Type, nil] the
   #   containing resource or nil if there is no catalog or no containing
   #   resource.
   def parent
     return nil unless catalog
 
     @parent ||=
       if parents = catalog.adjacent(self, :direction => :in)
         parents.shift
       else
         nil
       end
   end
 
   # Returns a reference to this as a string in "Type[name]" format.
   # @return [String] a reference to this object on the form 'Type[name]'
   #
   def ref
     # memoizing this is worthwhile ~ 3 percent of calls are the "first time
     # around" in an average run of Puppet. --daniel 2012-07-17
     @ref ||= "#{self.class.name.to_s.capitalize}[#{self.title}]"
   end
 
   # (see self_refresh)
   # @todo check that meaningful yardoc is produced - this method delegates to "self.class.self_refresh"
   # @return [Boolean] - ??? returns true when ... what?
   #
   def self_refresh?
     self.class.self_refresh
   end
 
   # Marks the object as "being purged".
   # This method is used by transactions to forbid deletion when there are dependencies.
   # @todo what does this mean; "mark that we are purging" (purging what from where). How to use/when?
   #   Is this internal API in transactions?
   # @see purging?
   def purging
     @purging = true
   end
 
   # Returns whether this resource is being purged or not.
   # This method is used by transactions to forbid deletion when there are dependencies.
   # @return [Boolean] the current "purging" state
   #
   def purging?
     if defined?(@purging)
       @purging
     else
       false
     end
   end
 
   # Returns the title of this object, or its name if title was not explicetly set.
   # If the title is not already set, it will be computed by looking up the {#name_var} and using
   # that value as the title.
   # @todo it is somewhat confusing that if the name_var is a valid parameter, it is assumed to
   #  be the name_var called :name, but if it is a property, it uses the name_var.
   #  It is further confusing as Type in some respects supports multiple namevars.
   #
   # @return [String] Returns the title of this object, or its name if title was not explicetly set.
   # @raise [??? devfail] if title is not set, and name_var can not be found.
   def title
     unless @title
       if self.class.validparameter?(name_var)
         @title = self[:name]
       elsif self.class.validproperty?(name_var)
         @title = self.should(name_var)
       else
         self.devfail "Could not find namevar #{name_var} for #{self.class.name}"
       end
     end
 
     @title
   end
 
   # Produces a reference to this in reference format.
   # @see #ref
   #
   def to_s
     self.ref
   end
 
   # @todo What to resource? Which one of the resource forms is prroduced? returned here?
   # @return [??? Resource] a resource that WHAT???
   #
   def to_resource
     resource = self.retrieve_resource
     resource.tag(*self.tags)
 
     @parameters.each do |name, param|
       # Avoid adding each instance name twice
       next if param.class.isnamevar? and param.value == self.title
 
       # We've already got property values
       next if param.is_a?(Puppet::Property)
       resource[name] = param.value
     end
 
     resource
   end
 
   # @return [Boolean] Returns whether the resource is virtual or not
   def virtual?;  !!@virtual;  end
   # @return [Boolean] Returns whether the resource is exported or not
   def exported?; !!@exported; end
 
   # @return [Boolean] Returns whether the resource is applicable to `:device`
   # Returns true if a resource of this type can be evaluated on a 'network device' kind
   # of hosts.
   # @api private
   def appliable_to_device?
     self.class.can_apply_to(:device)
   end
 
   # @return [Boolean] Returns whether the resource is applicable to `:host`
   # Returns true if a resource of this type can be evaluated on a regular generalized computer (ie not an appliance like a network device)
   # @api private
   def appliable_to_host?
     self.class.can_apply_to(:host)
   end
 end
 end
 
 require 'puppet/provider'
diff --git a/spec/integration/transaction_spec.rb b/spec/integration/transaction_spec.rb
index fc1fff228..35557b8f2 100755
--- a/spec/integration/transaction_spec.rb
+++ b/spec/integration/transaction_spec.rb
@@ -1,346 +1,362 @@
 #! /usr/bin/env ruby
 require 'spec_helper'
 
 require 'puppet/transaction'
 
 describe Puppet::Transaction do
   include PuppetSpec::Files
 
   before do
     Puppet::Util::Storage.stubs(:store)
   end
 
   def mk_catalog(*resources)
     catalog = Puppet::Resource::Catalog.new(Puppet::Node.new("mynode"))
     resources.each { |res| catalog.add_resource res }
     catalog
   end
 
   def usr_bin_touch(path)
     Puppet.features.microsoft_windows? ? "#{ENV['windir']}/system32/cmd.exe /c \"type NUL >> \"#{path}\"\"" : "/usr/bin/touch #{path}"
   end
 
   def touch(path)
     Puppet.features.microsoft_windows? ? "cmd.exe /c \"type NUL >> \"#{path}\"\"" : "touch #{path}"
   end
 
   it "should not apply generated resources if the parent resource fails" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:file).new :path => make_absolute("/foo/bar"), :backup => false
     catalog.add_resource resource
 
     child_resource = Puppet::Type.type(:file).new :path => make_absolute("/foo/bar/baz"), :backup => false
 
     resource.expects(:eval_generate).returns([child_resource])
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
 
     resource.expects(:retrieve).raises "this is a failure"
     resource.stubs(:err)
 
     child_resource.expects(:retrieve).never
 
     transaction.evaluate
   end
 
   it "should not apply virtual resources" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:file).new :path => make_absolute("/foo/bar"), :backup => false
     resource.virtual = true
     catalog.add_resource resource
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
 
     resource.expects(:evaluate).never
 
     transaction.evaluate
   end
 
   it "should apply exported resources" do
     catalog = Puppet::Resource::Catalog.new
     path = tmpfile("exported_files")
     resource = Puppet::Type.type(:file).new :path => path, :backup => false, :ensure => :file
     resource.exported = true
     catalog.add_resource resource
 
     catalog.apply
     Puppet::FileSystem.exist?(path).should be_true
   end
 
   it "should not apply virtual exported resources" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:file).new :path => make_absolute("/foo/bar"), :backup => false
     resource.exported = true
     resource.virtual = true
     catalog.add_resource resource
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
 
     resource.expects(:evaluate).never
 
     transaction.evaluate
   end
 
   it "should not apply device resources on normal host" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:interface).new :name => "FastEthernet 0/1"
     catalog.add_resource resource
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     transaction.for_network_device = false
 
     transaction.expects(:apply).never.with(resource, nil)
 
     transaction.evaluate
     transaction.resource_status(resource).should be_skipped
   end
 
   it "should not apply host resources on device" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:file).new :path => make_absolute("/foo/bar"), :backup => false
     catalog.add_resource resource
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     transaction.for_network_device = true
 
     transaction.expects(:apply).never.with(resource, nil)
 
     transaction.evaluate
     transaction.resource_status(resource).should be_skipped
   end
 
   it "should apply device resources on device" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:interface).new :name => "FastEthernet 0/1"
     catalog.add_resource resource
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     transaction.for_network_device = true
 
     transaction.expects(:apply).with(resource, nil)
 
     transaction.evaluate
     transaction.resource_status(resource).should_not be_skipped
   end
 
   it "should apply resources appliable on host and device on a device" do
     catalog = Puppet::Resource::Catalog.new
     resource = Puppet::Type.type(:schedule).new :name => "test"
     catalog.add_resource resource
 
     transaction = Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     transaction.for_network_device = true
 
     transaction.expects(:apply).with(resource, nil)
 
     transaction.evaluate
     transaction.resource_status(resource).should_not be_skipped
   end
 
   # Verify that one component requiring another causes the contained
   # resources in the requiring component to get refreshed.
   it "should propagate events from a contained resource through its container to its dependent container's contained resources" do
     transaction = nil
     file = Puppet::Type.type(:file).new :path => tmpfile("event_propagation"), :ensure => :present
     execfile = File.join(tmpdir("exec_event"), "exectestingness2")
     exec = Puppet::Type.type(:exec).new :command => touch(execfile), :path => ENV['PATH']
     catalog = mk_catalog(file)
 
     fcomp = Puppet::Type.type(:component).new(:name => "Foo[file]")
     catalog.add_resource fcomp
     catalog.add_edge(fcomp, file)
 
     ecomp = Puppet::Type.type(:component).new(:name => "Foo[exec]")
     catalog.add_resource ecomp
     catalog.add_resource exec
     catalog.add_edge(ecomp, exec)
 
     ecomp[:subscribe] = Puppet::Resource.new(:foo, "file")
     exec[:refreshonly] = true
 
     exec.expects(:refresh)
     catalog.apply
   end
 
   # Make sure that multiple subscriptions get triggered.
   it "should propagate events to all dependent resources" do
     path = tmpfile("path")
     file1 = tmpfile("file1")
     file2 = tmpfile("file2")
 
     file = Puppet::Type.type(:file).new(
       :path   => path,
       :ensure => "file"
     )
 
     exec1 = Puppet::Type.type(:exec).new(
       :path    => ENV["PATH"],
       :command => touch(file1),
       :refreshonly => true,
       :subscribe   => Puppet::Resource.new(:file, path)
     )
 
     exec2 = Puppet::Type.type(:exec).new(
       :path        => ENV["PATH"],
       :command     => touch(file2),
       :refreshonly => true,
       :subscribe   => Puppet::Resource.new(:file, path)
     )
 
     catalog = mk_catalog(file, exec1, exec2)
     catalog.apply
     Puppet::FileSystem.exist?(file1).should be_true
     Puppet::FileSystem.exist?(file2).should be_true
   end
 
+  it "should apply no resources whatsoever if a pre_run_check fails" do
+    path = tmpfile("path")
+    file = Puppet::Type.type(:file).new(
+      :path => path,
+      :ensure => "file"
+    )
+    notify = Puppet::Type.type(:notify).new(
+      :title => "foo"
+    )
+    notify.expects(:pre_run_check).raises(Puppet::Error, "fail for testing")
+
+    catalog = mk_catalog(file, notify)
+    catalog.apply
+    Puppet::FileSystem.exist?(path).should_not be_true
+  end
+
   it "should not let one failed refresh result in other refreshes failing" do
     path = tmpfile("path")
     newfile = tmpfile("file")
       file = Puppet::Type.type(:file).new(
       :path => path,
       :ensure => "file"
     )
 
     exec1 = Puppet::Type.type(:exec).new(
       :path => ENV["PATH"],
       :command => touch(File.expand_path("/this/cannot/possibly/exist")),
       :logoutput => true,
       :refreshonly => true,
       :subscribe => file,
       :title => "one"
     )
 
     exec2 = Puppet::Type.type(:exec).new(
       :path => ENV["PATH"],
       :command => touch(newfile),
       :logoutput => true,
       :refreshonly => true,
       :subscribe => [file, exec1],
       :title => "two"
     )
 
     exec1.stubs(:err)
 
     catalog = mk_catalog(file, exec1, exec2)
     catalog.apply
     Puppet::FileSystem.exist?(newfile).should be_true
   end
 
   it "should still trigger skipped resources" do
     catalog = mk_catalog
     catalog.add_resource(*Puppet::Type.type(:schedule).mkdefaultschedules)
 
     Puppet[:ignoreschedules] = false
 
     file = Puppet::Type.type(:file).new(
       :name => tmpfile("file"),
       :ensure => "file",
       :backup => false
     )
 
     fname = tmpfile("exec")
 
     exec = Puppet::Type.type(:exec).new(
       :name => touch(fname),
       :path => Puppet.features.microsoft_windows? ? "#{ENV['windir']}/system32" : "/usr/bin:/bin",
       :schedule => "monthly",
       :subscribe => Puppet::Resource.new("file", file.name)
     )
 
     catalog.add_resource(file, exec)
 
     # Run it once
     catalog.apply
     Puppet::FileSystem.exist?(fname).should be_true
 
     # Now remove it, so it can get created again
     Puppet::FileSystem.unlink(fname)
 
     file[:content] = "some content"
 
     catalog.apply
     Puppet::FileSystem.exist?(fname).should be_true
 
     # Now remove it, so it can get created again
     Puppet::FileSystem.unlink(fname)
 
     # And tag our exec
     exec.tag("testrun")
 
     # And our file, so it runs
     file.tag("norun")
 
     Puppet[:tags] = "norun"
 
     file[:content] = "totally different content"
 
     catalog.apply
     Puppet::FileSystem.exist?(fname).should be_true
   end
 
   it "should not attempt to evaluate resources with failed dependencies" do
 
     exec = Puppet::Type.type(:exec).new(
       :command => "#{File.expand_path('/bin/mkdir')} /this/path/cannot/possibly/exist",
       :title => "mkdir"
     )
 
     file1 = Puppet::Type.type(:file).new(
       :title => "file1",
       :path => tmpfile("file1"),
       :require => exec,
       :ensure => :file
     )
 
     file2 = Puppet::Type.type(:file).new(
       :title => "file2",
       :path => tmpfile("file2"),
       :require => file1,
       :ensure => :file
     )
 
     catalog = mk_catalog(exec, file1, file2)
     catalog.apply
 
     Puppet::FileSystem.exist?(file1[:path]).should be_false
     Puppet::FileSystem.exist?(file2[:path]).should be_false
   end
 
   it "should not trigger subscribing resources on failure" do
     file1 = tmpfile("file1")
     file2 = tmpfile("file2")
 
     create_file1 = Puppet::Type.type(:exec).new(
       :command => usr_bin_touch(file1)
     )
 
     exec = Puppet::Type.type(:exec).new(
       :command => "#{File.expand_path('/bin/mkdir')} /this/path/cannot/possibly/exist",
       :title => "mkdir",
       :notify => create_file1
     )
 
     create_file2 = Puppet::Type.type(:exec).new(
       :command => usr_bin_touch(file2),
       :subscribe => exec
     )
 
     catalog = mk_catalog(exec, create_file1, create_file2)
     catalog.apply
 
     Puppet::FileSystem.exist?(file1).should be_false
     Puppet::FileSystem.exist?(file2).should be_false
   end
 
   # #801 -- resources only checked in noop should be rescheduled immediately.
   it "should immediately reschedule noop resources" do
     Puppet::Type.type(:schedule).mkdefaultschedules
     resource = Puppet::Type.type(:notify).new(:name => "mymessage", :noop => true)
     catalog = Puppet::Resource::Catalog.new
     catalog.add_resource resource
 
     trans = catalog.apply
 
     trans.resource_harness.should be_scheduled(resource)
   end
 end
diff --git a/spec/unit/transaction_spec.rb b/spec/unit/transaction_spec.rb
index 04ce08c4f..01aac5516 100755
--- a/spec/unit/transaction_spec.rb
+++ b/spec/unit/transaction_spec.rb
@@ -1,671 +1,689 @@
 #! /usr/bin/env ruby
 require 'spec_helper'
 require 'matchers/include_in_order'
 require 'puppet_spec/compiler'
 
 require 'puppet/transaction'
 require 'fileutils'
 
 describe Puppet::Transaction do
   include PuppetSpec::Files
   include PuppetSpec::Compiler
 
   def catalog_with_resource(resource)
     catalog = Puppet::Resource::Catalog.new
     catalog.add_resource(resource)
     catalog
   end
 
   def transaction_with_resource(resource)
     transaction = Puppet::Transaction.new(catalog_with_resource(resource), nil, Puppet::Graph::RandomPrioritizer.new)
     transaction
   end
 
   before do
     @basepath = make_absolute("/what/ever")
     @transaction = Puppet::Transaction.new(Puppet::Resource::Catalog.new, nil, Puppet::Graph::RandomPrioritizer.new)
   end
 
   it "should be able to look resource status up by resource reference" do
     resource = Puppet::Type.type(:notify).new :title => "foobar"
     transaction = transaction_with_resource(resource)
     transaction.evaluate
 
     transaction.resource_status(resource.to_s).should be_changed
   end
 
   # This will basically only ever be used during testing.
   it "should automatically create resource statuses if asked for a non-existent status" do
     resource = Puppet::Type.type(:notify).new :title => "foobar"
     @transaction.resource_status(resource).should be_instance_of(Puppet::Resource::Status)
   end
 
   it "should add provided resource statuses to its report" do
     resource = Puppet::Type.type(:notify).new :title => "foobar"
     transaction = transaction_with_resource(resource)
     transaction.evaluate
 
     status = transaction.resource_status(resource)
     transaction.report.resource_statuses[resource.to_s].should equal(status)
   end
 
   it "should not consider there to be failed resources if no statuses are marked failed" do
     resource = Puppet::Type.type(:notify).new :title => "foobar"
     transaction = transaction_with_resource(resource)
     transaction.evaluate
 
     transaction.should_not be_any_failed
   end
 
   it "should use the provided report object" do
     report = Puppet::Transaction::Report.new("apply")
     transaction = Puppet::Transaction.new(Puppet::Resource::Catalog.new, report, nil)
 
     transaction.report.should == report
   end
 
   it "should create a report if none is provided" do
     transaction = Puppet::Transaction.new(Puppet::Resource::Catalog.new, nil, nil)
 
     transaction.report.should be_kind_of Puppet::Transaction::Report
   end
 
   describe "when initializing" do
     it "should create an event manager" do
       @transaction = Puppet::Transaction.new(Puppet::Resource::Catalog.new, nil, nil)
       @transaction.event_manager.should be_instance_of(Puppet::Transaction::EventManager)
       @transaction.event_manager.transaction.should equal(@transaction)
     end
 
     it "should create a resource harness" do
       @transaction = Puppet::Transaction.new(Puppet::Resource::Catalog.new, nil, nil)
       @transaction.resource_harness.should be_instance_of(Puppet::Transaction::ResourceHarness)
       @transaction.resource_harness.transaction.should equal(@transaction)
     end
 
     it "should set retrieval time on the report" do
       catalog = Puppet::Resource::Catalog.new
       report = Puppet::Transaction::Report.new("apply")
       catalog.retrieval_duration = 5
 
       report.expects(:add_times).with(:config_retrieval, 5)
 
       transaction = Puppet::Transaction.new(catalog, report, nil)
     end
   end
 
   describe "when evaluating a resource" do
     before do
       @catalog = Puppet::Resource::Catalog.new
       @resource = Puppet::Type.type(:file).new :path => @basepath
       @catalog.add_resource(@resource)
 
       @transaction = Puppet::Transaction.new(@catalog, nil, Puppet::Graph::RandomPrioritizer.new)
       @transaction.stubs(:skip?).returns false
     end
 
     it "should process events" do
       @transaction.event_manager.expects(:process_events).with(@resource)
 
       @transaction.evaluate
     end
 
     describe "and the resource should be skipped" do
       before do
         @transaction.expects(:skip?).with(@resource).returns true
       end
 
       it "should mark the resource's status as skipped" do
         @transaction.evaluate
         @transaction.resource_status(@resource).should be_skipped
       end
     end
   end
 
   describe "when applying a resource" do
     before do
       @catalog = Puppet::Resource::Catalog.new
       @resource = Puppet::Type.type(:file).new :path => @basepath
       @catalog.add_resource(@resource)
       @status = Puppet::Resource::Status.new(@resource)
 
       @transaction = Puppet::Transaction.new(@catalog, nil, Puppet::Graph::RandomPrioritizer.new)
       @transaction.event_manager.stubs(:queue_events)
     end
 
     it "should use its resource harness to apply the resource" do
       @transaction.resource_harness.expects(:evaluate).with(@resource)
       @transaction.evaluate
     end
 
     it "should add the resulting resource status to its status list" do
       @transaction.resource_harness.stubs(:evaluate).returns(@status)
       @transaction.evaluate
       @transaction.resource_status(@resource).should be_instance_of(Puppet::Resource::Status)
     end
 
     it "should queue any events added to the resource status" do
       @transaction.resource_harness.stubs(:evaluate).returns(@status)
       @status.expects(:events).returns %w{a b}
       @transaction.event_manager.expects(:queue_events).with(@resource, ["a", "b"])
       @transaction.evaluate
     end
 
     it "should log and skip any resources that cannot be applied" do
       @resource.expects(:properties).raises ArgumentError
       @transaction.evaluate
       @transaction.report.resource_statuses[@resource.to_s].should be_failed
     end
 
     it "should report any_failed if any resources failed" do
       @resource.expects(:properties).raises ArgumentError
       @transaction.evaluate
 
       expect(@transaction).to be_any_failed
     end
   end
 
   describe "#unblock" do
     let(:graph) { @transaction.relationship_graph }
     let(:resource) { Puppet::Type.type(:notify).new(:name => 'foo') }
 
     it "should calculate the number of blockers if it's not known" do
       graph.add_vertex(resource)
       3.times do |i|
         other = Puppet::Type.type(:notify).new(:name => i.to_s)
         graph.add_vertex(other)
         graph.add_edge(other, resource)
       end
 
       graph.unblock(resource)
 
       graph.blockers[resource].should == 2
     end
 
     it "should decrement the number of blockers if there are any" do
       graph.blockers[resource] = 40
 
       graph.unblock(resource)
 
       graph.blockers[resource].should == 39
     end
 
     it "should warn if there are no blockers" do
       vertex = stub('vertex')
       vertex.expects(:warning).with "appears to have a negative number of dependencies"
       graph.blockers[vertex] = 0
 
       graph.unblock(vertex)
     end
 
     it "should return true if the resource is now unblocked" do
       graph.blockers[resource] = 1
 
       graph.unblock(resource).should == true
     end
 
     it "should return false if the resource is still blocked" do
       graph.blockers[resource] = 2
 
       graph.unblock(resource).should == false
     end
   end
 
   describe "when traversing" do
     let(:path) { tmpdir('eval_generate') }
     let(:resource) { Puppet::Type.type(:file).new(:path => path, :recurse => true) }
 
     before :each do
       @transaction.catalog.add_resource(resource)
     end
 
     it "should yield the resource even if eval_generate is called" do
       Puppet::Transaction::AdditionalResourceGenerator.any_instance.expects(:eval_generate).with(resource).returns true
 
       yielded = false
       @transaction.evaluate do |res|
         yielded = true if res == resource
       end
 
       yielded.should == true
     end
 
     it "should prefetch the provider if necessary" do
       @transaction.expects(:prefetch_if_necessary).with(resource)
 
       @transaction.evaluate {}
     end
 
     it "traverses independent resources before dependent resources" do
       dependent = Puppet::Type.type(:notify).new(:name => "hello", :require => resource)
       @transaction.catalog.add_resource(dependent)
 
       seen = []
       @transaction.evaluate do |res|
         seen << res
       end
 
       expect(seen).to include_in_order(resource, dependent)
     end
 
     it "traverses completely independent resources in the order they appear in the catalog" do
       independent = Puppet::Type.type(:notify).new(:name => "hello", :require => resource)
       @transaction.catalog.add_resource(independent)
 
       seen = []
       @transaction.evaluate do |res|
         seen << res
       end
 
       expect(seen).to include_in_order(resource, independent)
     end
 
     it "should fail unsuitable resources and go on if it gets blocked" do
       dependent = Puppet::Type.type(:notify).new(:name => "hello", :require => resource)
       @transaction.catalog.add_resource(dependent)
 
       resource.stubs(:suitable?).returns false
 
       evaluated = []
       @transaction.evaluate do |res|
         evaluated << res
       end
 
       # We should have gone on to evaluate the children
       evaluated.should == [dependent]
       @transaction.resource_status(resource).should be_failed
     end
   end
 
   describe "when generating resources before traversal" do
     let(:catalog) { Puppet::Resource::Catalog.new }
     let(:transaction) { Puppet::Transaction.new(catalog, nil, Puppet::Graph::RandomPrioritizer.new) }
     let(:generator) { Puppet::Type.type(:notify).new :title => "generator" }
     let(:generated) do
       %w[a b c].map { |name| Puppet::Type.type(:notify).new(:name => name) }
     end
 
     before :each do
       catalog.add_resource generator
       generator.stubs(:generate).returns generated
     end
 
     it "should call 'generate' on all created resources" do
       generated.each { |res| res.expects(:generate) }
 
       transaction.evaluate
     end
 
     it "should finish all resources" do
       generated.each { |res| res.expects(:finish) }
 
       transaction.evaluate
     end
 
     it "should copy all tags to the newly generated resources" do
       generator.tag('one', 'two')
 
       transaction.evaluate
 
       generated.each do |res|
         res.must be_tagged(*generator.tags)
       end
     end
   end
 
+  describe "when performing pre-run checks" do
+    let(:resource) { Puppet::Type.type(:notify).new :title => "spec" }
+    let(:transaction) { transaction_with_resource(resource) }
+
+    it "should invoke each resource's hook and apply the catalog after no failures" do
+      resource.expects(:pre_run_check) # raises nothing!
+      transaction.relationship_graph.expects(:traverse)
+      transaction.evaluate
+    end
+
+    it "should abort the transaction on failure, but catch the exception" do
+      resource.stubs(:pre_run_check).raises(Puppet::Error, "spec-exception")
+      Puppet.expects(:info).with { |msg| msg =~ /^Applying configuration/ }.never
+      expect { transaction.evaluate }.to raise_error(Puppet::Error)
+      expect { transaction.evaluate }.to_not raise_error(/spec-exception/)
+    end
+  end
+
   describe "when skipping a resource" do
     before :each do
       @resource = Puppet::Type.type(:notify).new :name => "foo"
       @catalog = Puppet::Resource::Catalog.new
       @resource.catalog = @catalog
       @transaction = Puppet::Transaction.new(@catalog, nil, nil)
     end
 
     it "should skip resource with missing tags" do
       @transaction.stubs(:missing_tags?).returns(true)
       @transaction.should be_skip(@resource)
     end
 
     it "should skip unscheduled resources" do
       @transaction.stubs(:scheduled?).returns(false)
       @transaction.should be_skip(@resource)
     end
 
     it "should skip resources with failed dependencies" do
       @transaction.stubs(:failed_dependencies?).returns(true)
       @transaction.should be_skip(@resource)
     end
 
     it "should skip virtual resource" do
       @resource.stubs(:virtual?).returns true
       @transaction.should be_skip(@resource)
     end
 
     it "should skip device only resouce on normal host" do
       @resource.stubs(:appliable_to_host?).returns false
       @resource.stubs(:appliable_to_device?).returns true
       @transaction.for_network_device = false
       @transaction.should be_skip(@resource)
     end
 
     it "should not skip device only resouce on remote device" do
       @resource.stubs(:appliable_to_host?).returns false
       @resource.stubs(:appliable_to_device?).returns true
       @transaction.for_network_device = true
       @transaction.should_not be_skip(@resource)
     end
 
     it "should skip host resouce on device" do
       @resource.stubs(:appliable_to_host?).returns true
       @resource.stubs(:appliable_to_device?).returns false
       @transaction.for_network_device = true
       @transaction.should be_skip(@resource)
     end
 
     it "should not skip resouce available on both device and host when on device" do
       @resource.stubs(:appliable_to_host?).returns true
       @resource.stubs(:appliable_to_device?).returns true
       @transaction.for_network_device = true
       @transaction.should_not be_skip(@resource)
     end
 
     it "should not skip resouce available on both device and host when on host" do
       @resource.stubs(:appliable_to_host?).returns true
       @resource.stubs(:appliable_to_device?).returns true
       @transaction.for_network_device = false
       @transaction.should_not be_skip(@resource)
     end
   end
 
   describe "when determining if tags are missing" do
     before :each do
       @resource = Puppet::Type.type(:notify).new :name => "foo"
       @catalog = Puppet::Resource::Catalog.new
       @resource.catalog = @catalog
       @transaction = Puppet::Transaction.new(@catalog, nil, nil)
 
       @transaction.stubs(:ignore_tags?).returns false
     end
 
     it "should not be missing tags if tags are being ignored" do
       @transaction.expects(:ignore_tags?).returns true
 
       @resource.expects(:tagged?).never
 
       @transaction.should_not be_missing_tags(@resource)
     end
 
     it "should not be missing tags if the transaction tags are empty" do
       @transaction.tags = []
       @resource.expects(:tagged?).never
       @transaction.should_not be_missing_tags(@resource)
     end
 
     it "should otherwise let the resource determine if it is missing tags" do
       tags = ['one', 'two']
       @transaction.tags = tags
       @transaction.should be_missing_tags(@resource)
     end
   end
 
   describe "when determining if a resource should be scheduled" do
     before :each do
       @resource = Puppet::Type.type(:notify).new :name => "foo"
       @catalog = Puppet::Resource::Catalog.new
       @catalog.add_resource(@resource)
       @transaction = Puppet::Transaction.new(@catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     end
 
     it "should always schedule resources if 'ignoreschedules' is set" do
       @transaction.ignoreschedules = true
       @transaction.resource_harness.expects(:scheduled?).never
 
       @transaction.evaluate
       @transaction.resource_status(@resource).should be_changed
     end
 
     it "should let the resource harness determine whether the resource should be scheduled" do
       @transaction.resource_harness.expects(:scheduled?).with(@resource).returns "feh"
 
       @transaction.evaluate
     end
   end
 
   describe "when prefetching" do
     let(:catalog) { Puppet::Resource::Catalog.new }
     let(:transaction) { Puppet::Transaction.new(catalog, nil, nil) }
     let(:resource) { Puppet::Type.type(:sshkey).new :title => "foo", :name => "bar", :type => :dsa, :key => "eh", :provider => :parsed }
     let(:resource2) { Puppet::Type.type(:package).new :title => "blah", :provider => "apt" }
 
     before :each do
       catalog.add_resource resource
       catalog.add_resource resource2
     end
 
     it "should match resources by name, not title" do
       resource.provider.class.expects(:prefetch).with("bar" => resource)
 
       transaction.prefetch_if_necessary(resource)
     end
 
     it "should not prefetch a provider which has already been prefetched" do
       transaction.prefetched_providers[:sshkey][:parsed] = true
 
       resource.provider.class.expects(:prefetch).never
 
       transaction.prefetch_if_necessary(resource)
     end
 
     it "should mark the provider prefetched" do
       resource.provider.class.stubs(:prefetch)
 
       transaction.prefetch_if_necessary(resource)
 
       transaction.prefetched_providers[:sshkey][:parsed].should be_true
     end
 
     it "should prefetch resources without a provider if prefetching the default provider" do
       other = Puppet::Type.type(:sshkey).new :name => "other"
 
       other.instance_variable_set(:@provider, nil)
 
       catalog.add_resource other
 
       resource.provider.class.expects(:prefetch).with('bar' => resource, 'other' => other)
 
       transaction.prefetch_if_necessary(resource)
     end
   end
 
   describe "during teardown" do
     before :each do
       @catalog = Puppet::Resource::Catalog.new
       @transaction = Puppet::Transaction.new(@catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     end
 
     it "should call ::post_resource_eval on provider classes that support it" do
       @resource = Puppet::Type.type(:notify).new :title => "foo"
       @catalog.add_resource @resource
 
       # 'expects' will cause 'respond_to?(:post_resource_eval)' to return true
       @resource.provider.class.expects(:post_resource_eval)
       @transaction.evaluate
     end
 
     it "should call ::post_resource_eval even if other providers' ::post_resource_eval fails" do
       @resource3 = Puppet::Type.type(:user).new :title => "bloo"
       @resource3.provider.class.stubs(:post_resource_eval).raises
       @resource4 = Puppet::Type.type(:notify).new :title => "blob"
       @resource4.provider.class.stubs(:post_resource_eval).raises
       @catalog.add_resource @resource3
       @catalog.add_resource @resource4
 
       # ruby's Set does not guarantee ordering, so both resource3 and resource4
       # need to expect post_resource_eval, rather than just the 'first' one.
       @resource3.provider.class.expects(:post_resource_eval)
       @resource4.provider.class.expects(:post_resource_eval)
 
       @transaction.evaluate
     end
 
     it "should call ::post_resource_eval even if one of the resources fails" do
       @resource3 = Puppet::Type.type(:notify).new :title => "bloo"
       @resource3.stubs(:retrieve_resource).raises
       @catalog.add_resource @resource3
 
       @resource3.provider.class.expects(:post_resource_eval)
 
       @transaction.evaluate
     end
   end
 
   describe 'when checking application run state' do
     before do
       @catalog = Puppet::Resource::Catalog.new
       @transaction = Puppet::Transaction.new(@catalog, nil, Puppet::Graph::RandomPrioritizer.new)
     end
 
     context "when stop is requested" do
       before :each do
         Puppet::Application.stubs(:stop_requested?).returns(true)
       end
 
       it 'should return true for :stop_processing?' do
         @transaction.should be_stop_processing
       end
 
       it 'always evaluates non-host_config catalogs' do
         @catalog.host_config = false
         @transaction.should_not be_stop_processing
       end
     end
 
     it 'should return false for :stop_processing? if Puppet::Application.stop_requested? is false' do
       Puppet::Application.stubs(:stop_requested?).returns(false)
       @transaction.stop_processing?.should be_false
     end
 
     describe 'within an evaluate call' do
       before do
         @resource = Puppet::Type.type(:notify).new :title => "foobar"
         @catalog.add_resource @resource
         @transaction.stubs(:add_dynamically_generated_resources)
       end
 
       it 'should stop processing if :stop_processing? is true' do
         @transaction.stubs(:stop_processing?).returns(true)
         @transaction.expects(:eval_resource).never
         @transaction.evaluate
       end
 
       it 'should continue processing if :stop_processing? is false' do
         @transaction.stubs(:stop_processing?).returns(false)
         @transaction.expects(:eval_resource).returns(nil)
         @transaction.evaluate
       end
     end
   end
 
   it "errors with a dependency cycle for a resource that requires itself" do
     expect do
       apply_compiled_manifest(<<-MANIFEST)
         notify { cycle: require => Notify[cycle] }
       MANIFEST
     end.to raise_error(Puppet::Error, /Found 1 dependency cycle:.*\(Notify\[cycle\] => Notify\[cycle\]\)/m)
   end
 
   it "errors with a dependency cycle for a self-requiring resource also required by another resource" do
     expect do
       apply_compiled_manifest(<<-MANIFEST)
         notify { cycle: require => Notify[cycle] }
         notify { other: require => Notify[cycle] }
       MANIFEST
     end.to raise_error(Puppet::Error, /Found 1 dependency cycle:.*\(Notify\[cycle\] => Notify\[cycle\]\)/m)
   end
 
   it "errors with a dependency cycle for a resource that requires itself and another resource" do
     expect do
       apply_compiled_manifest(<<-MANIFEST)
         notify { cycle:
           require => [Notify[other], Notify[cycle]]
         }
         notify { other: }
       MANIFEST
     end.to raise_error(Puppet::Error, /Found 1 dependency cycle:.*\(Notify\[cycle\] => Notify\[cycle\]\)/m)
   end
 
   it "errors with a dependency cycle for a resource that is later modified to require itself" do
     expect do
       apply_compiled_manifest(<<-MANIFEST)
         notify { cycle: }
         Notify <| title == 'cycle' |> {
           require => Notify[cycle]
         }
       MANIFEST
     end.to raise_error(Puppet::Error, /Found 1 dependency cycle:.*\(Notify\[cycle\] => Notify\[cycle\]\)/m)
   end
 
   it "reports a changed resource with a successful run" do
     transaction = apply_compiled_manifest("notify { one: }")
 
     transaction.report.status.should == 'changed'
     transaction.report.resource_statuses['Notify[one]'].should be_changed
   end
 
   describe "when interrupted" do
     it "marks unprocessed resources as skipped" do
       Puppet::Application.stop!
 
       transaction = apply_compiled_manifest(<<-MANIFEST)
         notify { a: } ->
         notify { b: }
       MANIFEST
 
       transaction.report.resource_statuses['Notify[a]'].should be_skipped
       transaction.report.resource_statuses['Notify[b]'].should be_skipped
     end
   end
 end
 
 describe Puppet::Transaction, " when determining tags" do
   before do
     @config = Puppet::Resource::Catalog.new
     @transaction = Puppet::Transaction.new(@config, nil, nil)
   end
 
   it "should default to the tags specified in the :tags setting" do
     Puppet[:tags] = "one"
     @transaction.should be_tagged("one")
   end
 
   it "should split tags based on ','" do
     Puppet[:tags] = "one,two"
     @transaction.should be_tagged("one")
     @transaction.should be_tagged("two")
   end
 
   it "should use any tags set after creation" do
     Puppet[:tags] = ""
     @transaction.tags = %w{one two}
     @transaction.should be_tagged("one")
     @transaction.should be_tagged("two")
   end
 
   it "should always convert assigned tags to an array" do
     @transaction.tags = "one::two"
     @transaction.should be_tagged("one::two")
   end
 
   it "should accept a comma-delimited string" do
     @transaction.tags = "one, two"
     @transaction.should be_tagged("one")
     @transaction.should be_tagged("two")
   end
 
   it "should accept an empty string" do
     @transaction.tags = "one, two"
     @transaction.should be_tagged("one")
     @transaction.tags = ""
     @transaction.should_not be_tagged("one")
   end
 end