make include_recipe "::foo" use current cookbook

The following code is brittle if you want to fork the cookbook and rename it
(which is a best practice when forking cookbooks for internal use):

```ruby
if node[:platform_family] == "rhel"
  include_recipe "mycookbook::_rhel"
end
```

In order for cookbooks to be easily renamable they can currently use the
syntax `include_recipe "#{cookbook_name}::_rhel"` which is unwieldy.
This patch adds `include_recipe "::_rhel"` as syntax sugar to make this
easier.

5 files changed, 47 insertions, 11 deletions

diff --git a/lib/chef/dsl/include_recipe.rb b/lib/chef/dsl/include_recipe.rb
index fc95e38c75..5ea1075e67 100644
--- a/lib/chef/dsl/include_recipe.rb
+++ b/lib/chef/dsl/include_recipe.rb
@@ -23,11 +23,11 @@ class Chef
     module IncludeRecipe
 
       def include_recipe(*recipe_names)
-        run_context.include_recipe(*recipe_names)
+        run_context.include_recipe(*recipe_names, current_cookbook: cookbook_name)
       end
 
       def load_recipe(recipe_name)
-        run_context.load_recipe(recipe_name)
+        run_context.load_recipe(recipe_name, current_cookbook: cookbook_name)
       end
 
       def require_recipe(*args)
@@ -42,4 +42,3 @@ end
 # **DEPRECATED**
 # This used to be part of chef/mixin/language_include_recipe. Load the file to activate the deprecation code.
 require 'chef/mixin/language_include_recipe'
-
diff --git a/lib/chef/recipe.rb b/lib/chef/recipe.rb
index 621d93099b..91f7f30aa9 100644
--- a/lib/chef/recipe.rb
+++ b/lib/chef/recipe.rb
@@ -54,12 +54,16 @@ class Chef
     # For example:
     #   "aws::elastic_ip" returns [:aws, "elastic_ip"]
     #   "aws" returns [:aws, "default"]
+    #   "::elastic_ip" returns [ current_cookbook, "elastic_ip" ]
     #--
     # TODO: Duplicates functionality of RunListItem
-    def self.parse_recipe_name(recipe_name)
-      rmatch = recipe_name.match(/(.+?)::(.+)/)
-      if rmatch
-        [ rmatch[1].to_sym, rmatch[2] ]
+    def self.parse_recipe_name(recipe_name, current_cookbook: nil)
+      case recipe_name
+      when /(.+?)::(.+)/
+        [ $1.to_sym, $2 ]
+      when /^::(.+)/
+        raise "current_cookbook is nil, cannot resolve #{recipe_name}" if current_cookbook.nil?
+        [ current_cookbook.to_sym, $1 ]
       else
         [ recipe_name.to_sym, "default" ]
       end
diff --git a/lib/chef/run_context.rb b/lib/chef/run_context.rb
index 6803dc5796..bb1bf28ad7 100644
--- a/lib/chef/run_context.rb
+++ b/lib/chef/run_context.rb
@@ -136,10 +136,10 @@ class Chef
     end
 
     # Evaluates the recipes +recipe_names+. Used by DSL::IncludeRecipe
-    def include_recipe(*recipe_names)
+    def include_recipe(*recipe_names, current_cookbook: nil)
       result_recipes = Array.new
       recipe_names.flatten.each do |recipe_name|
-        if result = load_recipe(recipe_name)
+        if result = load_recipe(recipe_name, current_cookbook: current_cookbook)
           result_recipes << result
         end
       end
@@ -147,10 +147,10 @@ class Chef
     end
 
     # Evaluates the recipe +recipe_name+. Used by DSL::IncludeRecipe
-    def load_recipe(recipe_name)
+    def load_recipe(recipe_name, current_cookbook: nil)
       Chef::Log.debug("Loading Recipe #{recipe_name} via include_recipe")
 
-      cookbook_name, recipe_short_name = Chef::Recipe.parse_recipe_name(recipe_name)
+      cookbook_name, recipe_short_name = Chef::Recipe.parse_recipe_name(recipe_name, current_cookbook: current_cookbook)
 
       if unreachable_cookbook?(cookbook_name) # CHEF-4367
         Chef::Log.warn(<<-ERROR_MESSAGE)
diff --git a/spec/unit/recipe_spec.rb b/spec/unit/recipe_spec.rb
index 22389a1a82..5ade7c86e2 100644
--- a/spec/unit/recipe_spec.rb
+++ b/spec/unit/recipe_spec.rb
@@ -501,6 +501,34 @@ describe Chef::Recipe do
       expect(cookbook_collection[:openldap]).not_to receive(:load_recipe).with("default", run_context)
       recipe.include_recipe "openldap"
     end
+
+    it "will load a recipe out of the current cookbook when include_recipe is called with a leading ::" do
+      openldap_recipe = Chef::Recipe.new("openldap", "test", run_context)
+      expect(node).to receive(:loaded_recipe).with(:openldap, "default").exactly(:once)
+      allow(run_context).to receive(:unreachable_cookbook?).with(:openldap).and_return(false)
+      expect(cookbook_collection[:openldap]).to receive(:load_recipe).with("default", run_context)
+      openldap_recipe.include_recipe "::default"
+    end
+
+    it "will not include the same recipe twice when using leading :: syntax" do
+      openldap_recipe = Chef::Recipe.new("openldap", "test", run_context)
+      expect(node).to receive(:loaded_recipe).with(:openldap, "default").exactly(:once)
+      allow(run_context).to receive(:unreachable_cookbook?).with(:openldap).and_return(false)
+      expect(cookbook_collection[:openldap]).to receive(:load_recipe).with("default", run_context)
+      openldap_recipe.include_recipe "::default"
+      expect(cookbook_collection[:openldap]).not_to receive(:load_recipe).with("default", run_context)
+      openldap_recipe.include_recipe "openldap::default"
+    end
+
+    it "will not include the same recipe twice when using leading :: syntax (reversed order)" do
+      openldap_recipe = Chef::Recipe.new("openldap", "test", run_context)
+      expect(node).to receive(:loaded_recipe).with(:openldap, "default").exactly(:once)
+      allow(run_context).to receive(:unreachable_cookbook?).with(:openldap).and_return(false)
+      expect(cookbook_collection[:openldap]).to receive(:load_recipe).with("default", run_context)
+      openldap_recipe.include_recipe "openldap::default"
+      expect(cookbook_collection[:openldap]).not_to receive(:load_recipe).with("default", run_context)
+      openldap_recipe.include_recipe "::default"
+    end
   end
 
   describe "tags" do
diff --git a/spec/unit/run_context_spec.rb b/spec/unit/run_context_spec.rb
index ba4f2ede68..d656111a7d 100644
--- a/spec/unit/run_context_spec.rb
+++ b/spec/unit/run_context_spec.rb
@@ -104,6 +104,11 @@ describe Chef::RunContext do
       end.to raise_error(Chef::Exceptions::CookbookNotFound)
     end
 
+    it "raises an error on a recipe with a leading :: with no current_cookbook" do
+      expect do
+        run_context.include_recipe("::aliens")
+      end.to raise_error(RuntimeError)
+    end
   end
 
   describe "querying the contents of cookbooks" do