Light-weight resources (well, any resource that calls the provider setter method) can now specify the provider by the light-weight provider identifier via string or symbol.

Author: chris

chef/lib/chef/resource.rb

@@ -20,6 +20,7 @@
 require 'chef/mixin/params_validate'
 require 'chef/mixin/check_helper'
 require 'chef/mixin/language'
+require 'chef/mixin/convert_to_class_name'
 require 'chef/resource_collection'
 require 'chef/node'
 
@@ -29,6 +30,7 @@ class Resource
     include Chef::Mixin::CheckHelper
     include Chef::Mixin::ParamsValidate
     include Chef::Mixin::Language
+    include Chef::Mixin::ConvertToClassName
 
     attr_accessor :actions, :params, :provider, :updated, :allowed_actions, :collection, :cookbook_name, :recipe_name
     attr_reader :resource_name, :source_line, :node
@@ -84,9 +86,18 @@ def supports(args={})
     end
 
     def provider(arg=nil)
+      klass = if arg.kind_of?(String) || arg.kind_of?(Symbol)
+                begin
+                  Chef::Provider.const_get(convert_to_class_name(arg.to_s))
+                rescue NameError => e
+                  raise ArgumentError, "Undefined provider for #{arg}"
+                end
+              else
+                arg
+              end
       set_or_return(
         :provider,
-        arg,
+        klass,
         :kind_of => [ Class ]
       )
     end

features/cookbooks/lightweight_resources_and_providers.feature

@@ -15,6 +15,9 @@ Feature: Light-weight resources and providers
       | non_default_resource                      | Non-default resource             |
       | overridden_resource_initialize            | Overridden initialize            |
       | overridden_provider_load_current_resource | Overridden load_current_resource |
+      | provider_is_a_string                      | Provider is a string             |
+      | provider_is_a_symbol                      | Provider is a symbol             |
+      | provider_is_a_class                       | Provider is a class              |
 
   @client @api
   Scenario Outline: Chef client handles light-weight resources and providers
@@ -31,4 +34,6 @@ Feature: Light-weight resources and providers
       | non_default_resource                      | Non-default resource             |
       | overridden_resource_initialize            | Overridden initialize            |
       | overridden_provider_load_current_resource | Overridden load_current_resource |
-
+      | provider_is_a_string                      | Provider is a string             |
+      | provider_is_a_symbol                      | Provider is a symbol             |
+      | provider_is_a_class                       | Provider is a class              |

features/data/cookbooks/lwrp/recipes/default_everything.rb

@@ -2,6 +2,5 @@
   message "Default everything"
   action :print_message
 
-  # TODO: should we provide an implementation of the provider method for lwps that converts the provided string or symbol to the appropriate class, as well as allow for a class arg?
   provider Chef::Provider::Lwrp
 end

features/data/cookbooks/lwrp/recipes/provider_is_a_class.rb

@@ -0,0 +1,6 @@
+lwrp :provider_is_a_class do
+  message "Provider is a class"
+  action :print_message
+
+  provider Chef::Provider::Lwrp
+end

features/data/cookbooks/lwrp/recipes/provider_is_a_string.rb

@@ -0,0 +1,6 @@
+lwrp :provider_is_a_string do
+  message "Provider is a string"
+  action :print_message
+
+  provider "lwrp"
+end

features/data/cookbooks/lwrp/recipes/provider_is_a_symbol.rb

@@ -0,0 +1,6 @@
+lwrp :provider_is_a_symbol do
+  message "Provider is a symbol"
+  action :print_message
+
+  provider :lwrp
+end