Add insert_at to resource_collectionjk/insert_at

2 files changed, 50 insertions, 8 deletions

diff --git a/lib/chef/resource_collection.rb b/lib/chef/resource_collection.rb
index a528a18aed..181328a1fc 100644
--- a/lib/chef/resource_collection.rb
+++ b/lib/chef/resource_collection.rb
@@ -67,24 +67,33 @@ class Chef
     alias_method :push, :<<
 
     def insert(resource)
-      is_chef_resource(resource)
       if @insert_after_idx
         # in the middle of executing a run, so any resources inserted now should
         # be placed after the most recent addition done by the currently executing
         # resource
-        @resources.insert(@insert_after_idx + 1, resource)
-        # update name -> location mappings and register new resource
-        @resources_by_name.each_key do |key|
-          @resources_by_name[key] += 1 if @resources_by_name[key] > @insert_after_idx
-        end
-        @resources_by_name[resource.to_s] = @insert_after_idx + 1
+        insert_at(@insert_after_idx + 1, resource)
         @insert_after_idx += 1
       else
+        is_chef_resource(resource)
         @resources << resource
         @resources_by_name[resource.to_s] = @resources.length - 1
       end
     end
 
+    def insert_at(insert_at_index, *resources)
+      resources.each do |resource|
+        is_chef_resource(resource)
+      end
+      @resources.insert(insert_at_index, *resources)
+      # update name -> location mappings and register new resource
+      @resources_by_name.each_key do |key|
+        @resources_by_name[key] += resources.size if @resources_by_name[key] >= insert_at_index
+      end
+      resources.each_with_index do |resource, i|
+        @resources_by_name[resource.to_s] = insert_at_index + i
+      end
+    end
+
     def each
       @resources.each do |resource|
         yield resource
@@ -247,7 +256,7 @@ class Chef
 
       def is_chef_resource(arg)
         unless arg.kind_of?(Chef::Resource)
-          raise ArgumentError, "Members must be Chef::Resource's"
+          raise ArgumentError, "Cannot insert a #{arg.class} into a resource collection: must be a Chef::Resource or descendant thereof"
         end
         true
       end
diff --git a/spec/unit/resource_collection_spec.rb b/spec/unit/resource_collection_spec.rb
index cf62f5ff40..eddd92e098 100644
--- a/spec/unit/resource_collection_spec.rb
+++ b/spec/unit/resource_collection_spec.rb
@@ -88,6 +88,39 @@ describe Chef::ResourceCollection do
     end
   end
 
+  describe "insert_at" do
+    it "should accept only Chef::Resources" do
+      lambda { @rc.insert_at(0, @resource, @resource) }.should_not raise_error
+      lambda { @rc.insert_at(0, "string") }.should raise_error
+      lambda { @rc.insert_at(0, @resource, "string") }.should raise_error
+    end
+
+    it "should toss an error if it receives a bad index" do
+      @rc.insert_at(10, @resource)
+    end
+
+    it "should insert resources at the beginning when asked" do
+      @rc.insert(Chef::Resource::ZenMaster.new('1'))
+      @rc.insert(Chef::Resource::ZenMaster.new('2'))
+      @rc.insert_at(0, Chef::Resource::ZenMaster.new('X'))
+      @rc.all_resources.map { |r| r.name }.should == [ 'X', '1', '2' ]
+    end
+
+    it "should insert resources in the middle when asked" do
+      @rc.insert(Chef::Resource::ZenMaster.new('1'))
+      @rc.insert(Chef::Resource::ZenMaster.new('2'))
+      @rc.insert_at(1, Chef::Resource::ZenMaster.new('X'))
+      @rc.all_resources.map { |r| r.name }.should == [ '1', 'X', '2' ]
+    end
+
+    it "should insert resources at the end when asked" do
+      @rc.insert(Chef::Resource::ZenMaster.new('1'))
+      @rc.insert(Chef::Resource::ZenMaster.new('2'))
+      @rc.insert_at(2, Chef::Resource::ZenMaster.new('X'))
+      @rc.all_resources.map { |r| r.name }.should == [ '1', '2', 'X' ]
+    end
+  end
+
   describe "each" do
     it "should allow you to iterate over every resource in the collection" do
       load_up_resources