Sort identical "provides" alphabetically (for backcompat)

- Warn when multiple providers try to provide the same thing

4 files changed, 60 insertions, 45 deletions

diff --git a/lib/chef/platform/priority_map.rb b/lib/chef/platform/priority_map.rb
new file mode 100644
index 0000000000..3608975b51
--- /dev/null
+++ b/lib/chef/platform/priority_map.rb
@@ -0,0 +1,50 @@
+require 'chef/node_map'
+
+class Chef
+  class Platform
+    class PriorityMap < Chef::NodeMap
+      # @api private
+      def get_priority_array(node, key)
+        get(node, key)
+      end
+
+      # @api private
+      def set_priority_array(key, priority_array, *filter, &block)
+        priority_array = Array(priority_array)
+        set(key, priority_array, *filter, &block)
+        priority_array
+      end
+
+      # @api private
+      def list_handlers(node, key, **filters)
+        list(node, key, **filters).flatten(1).uniq
+      end
+
+      #
+      # Priority maps have one extra precedence: priority arrays override "provides,"
+      # and "provides" lines with identical filters sort by class name (ascending).
+      #
+      def compare_matchers(key, new_matcher, matcher)
+        # Priority arrays come before "provides"
+        if new_matcher[:value].is_a?(Array) != matcher[:value].is_a?(Array)
+          return new_matcher[:value].is_a?(Array) ? -1 : 1
+        end
+
+        cmp = super
+        if cmp == 0
+          # Sort by class name (ascending) as well, if all other properties
+          # are exactly equal
+          if new_matcher[:value].is_a?(Class) && !new_matcher[:override]
+            cmp = compare_matcher_properties(new_matcher, matcher) { |m| m[:value].name }
+            if cmp < 0
+              Chef::Log.warn "You are overriding #{key} on #{new_matcher[:filters].inspect} with #{new_matcher[:value].inspect}: used to be #{matcher[:value].inspect}. Use override: true if this is what you intended."
+            elsif cmp > 0
+              Chef::Log.warn "You declared a new resource #{new_matcher[:value].inspect} for resource #{key}, but it comes alphabetically after #{matcher[:value].inspect} and has the same filters (#{new_matcher[:filters].inspect}), so it will not be used. Use override: true if you want to use it for #{key}."
+            end
+          end
+        end
+        cmp
+      end
+    end
+  end
+end
diff --git a/lib/chef/platform/provider_mapping.rb b/lib/chef/platform/provider_mapping.rb
index e3a894c8ac..af17d8e1b4 100644
--- a/lib/chef/platform/provider_mapping.rb
+++ b/lib/chef/platform/provider_mapping.rb
@@ -201,8 +201,8 @@ class Chef
 
             begin
               result = Chef::Provider.const_get(class_name)
-              Chef::Log.warn("Class Chef::Provider::#{class_name} does not declare 'provides #{convert_to_snake_case(class_name).to_sym.inspect}'.")
-              Chef::Log.warn("This will no longer work in Chef 13: you must use 'provides' to provide DSL.")
+              Chef::Log.warn("Class Chef::Provider::#{class_name} does not declare 'resource_name #{convert_to_snake_case(class_name).to_sym.inspect}'.")
+              Chef::Log.warn("This will no longer work in Chef 13: you must use 'resource_name' to provide DSL.")
             rescue NameError
             end
           end
diff --git a/lib/chef/platform/provider_priority_map.rb b/lib/chef/platform/provider_priority_map.rb
index 9d703c9178..5599c74c2d 100644
--- a/lib/chef/platform/provider_priority_map.rb
+++ b/lib/chef/platform/provider_priority_map.rb
@@ -1,29 +1,11 @@
 require 'singleton'
+require 'chef/platform/priority_map'
 
 class Chef
   class Platform
-    class ProviderPriorityMap
+    # @api private
+    class ProviderPriorityMap < Chef::Platform::PriorityMap
       include Singleton
-
-      def get_priority_array(node, resource_name)
-        priority_map.get(node, resource_name.to_sym)
-      end
-
-      def set_priority_array(resource_name, priority_array, *filter, &block)
-        priority_map.set(resource_name.to_sym, Array(priority_array), *filter, &block)
-      end
-
-      # @api private
-      def list_handlers(node, resource_name)
-        priority_map.list(node, resource_name.to_sym).flatten(1).uniq
-      end
-
-      private
-
-      def priority_map
-        require 'chef/node_map'
-        @priority_map ||= Chef::NodeMap.new
-      end
     end
   end
 end
diff --git a/lib/chef/platform/resource_priority_map.rb b/lib/chef/platform/resource_priority_map.rb
index fb08debc53..aa57e3ddf0 100644
--- a/lib/chef/platform/resource_priority_map.rb
+++ b/lib/chef/platform/resource_priority_map.rb
@@ -1,34 +1,17 @@
 require 'singleton'
+require 'chef/platform/priority_map'
 
 class Chef
   class Platform
-    class ResourcePriorityMap
+    # @api private
+    class ResourcePriorityMap < Chef::Platform::PriorityMap
       include Singleton
 
-      def get_priority_array(node, resource_name, canonical: nil)
-        priority_map.get(node, resource_name.to_sym, canonical: canonical)
-      end
-
-      def set_priority_array(resource_name, priority_array, *filter, &block)
-        priority_map.set(resource_name.to_sym, Array(priority_array), *filter, &block)
-      end
-
       # @api private
-      def delete_canonical(resource_name, resource_class)
-        priority_map.delete_canonical(resource_name, resource_class)
-      end
-
-      # @api private
-      def list_handlers(*args)
-        priority_map.list(*args).flatten(1).uniq
+      def get_priority_array(node, resource_name, canonical: nil)
+        super(node, resource_name.to_sym, canonical: canonical)
       end
 
-      private
-
-      def priority_map
-        require 'chef/node_map'
-        @priority_map ||= Chef::NodeMap.new
-      end
     end
   end
 end