Merge pull request #1935 from eugeneius/configure_existing_example_gr…

…oups

Apply helper modules to existing groups when added

lib/rspec/core/configuration.rb

@@ -1134,6 +1134,7 @@ def exclusion_filter
       def include(mod, *filters)
         meta = Metadata.build_hash_from(filters, :warn_about_example_group_filtering)
         @include_modules.append(mod, meta)
+        configure_existing_groups(mod, meta, :safe_include)
       end
 
       # Tells RSpec to extend example groups with `mod`. Methods defined in
@@ -1169,6 +1170,7 @@ def include(mod, *filters)
       def extend(mod, *filters)
         meta = Metadata.build_hash_from(filters, :warn_about_example_group_filtering)
         @extend_modules.append(mod, meta)
+        configure_existing_groups(mod, meta, :safe_extend)
       end
 
       if RSpec::Support::RubyFeatures.module_prepends_supported?
@@ -1207,6 +1209,7 @@ def extend(mod, *filters)
         def prepend(mod, *filters)
           meta = Metadata.build_hash_from(filters, :warn_about_example_group_filtering)
           @prepend_modules.append(mod, meta)
+          configure_existing_groups(mod, meta, :safe_prepend)
         end
       end
 
@@ -1227,6 +1230,14 @@ def configure_group_with(group, module_list, application_method)
         end
       end
 
+      # @private
+      def configure_existing_groups(mod, meta, application_method)
+        RSpec.world.all_example_groups.each do |group|
+          next unless meta.empty? || MetadataFilter.apply?(:any?, meta, group.metadata)
+          __send__(application_method, mod, group)
+        end
+      end
+
       # @private
       #
       # Used internally to extend the singleton class of a single example's

lib/rspec/core/world.rb

@@ -77,10 +77,14 @@ def example_count(groups=example_groups)
           inject(0) { |a, e| a + e.filtered_examples.size }
       end
 
+      # @private
+      def all_example_groups
+        FlatMap.flat_map(example_groups) { |g| g.descendants }
+      end
+
       # @private
       def all_examples
-        flattened_groups = FlatMap.flat_map(example_groups) { |g| g.descendants }
-        FlatMap.flat_map(flattened_groups) { |g| g.examples }
+        FlatMap.flat_map(all_example_groups) { |g| g.examples }
       end
 
       # @api private

spec/rspec/core/configuration_spec.rb

@@ -879,6 +879,17 @@ def metadata_hash(*args)
           expect(group).not_to respond_to(:you_call_this_a_blt?)
           expect(group.new.you_call_this_a_blt?).to eq("egad man, where's the mayo?!?!?")
         end
+
+        it "includes the given module into each existing example group" do
+          group = RSpec.describe('does like, stuff and junk', :magic_key => :include) { }
+
+          RSpec.configure do |c|
+            c.include(InstanceLevelMethods)
+          end
+
+          expect(group).not_to respond_to(:you_call_this_a_blt?)
+          expect(group.new.you_call_this_a_blt?).to eq("egad man, where's the mayo?!?!?")
+        end
       end
 
       context "with a filter" do
@@ -892,6 +903,17 @@ def metadata_hash(*args)
           expect(group.new.you_call_this_a_blt?).to eq("egad man, where's the mayo?!?!?")
         end
 
+        it "includes the given module into each existing matching example group" do
+          group = RSpec.describe('does like, stuff and junk', :magic_key => :include) { }
+
+          RSpec.configure do |c|
+            c.include(InstanceLevelMethods, :magic_key => :include)
+          end
+
+          expect(group).not_to respond_to(:you_call_this_a_blt?)
+          expect(group.new.you_call_this_a_blt?).to eq("egad man, where's the mayo?!?!?")
+        end
+
         it "includes the given module into the singleton class of matching examples" do
           RSpec.configure do |c|
             c.include(InstanceLevelMethods, :magic_key => :include)
@@ -981,6 +1003,15 @@ def metadata_hash(*args)
         expect(group).to respond_to(:that_thing)
       end
 
+      it "extends the given module into each existing matching example group" do
+        group = RSpec.describe(ThatThingISentYou, :magic_key => :extend) { }
+
+        RSpec.configure do |c|
+          c.extend(ThatThingISentYou, :magic_key => :extend)
+        end
+
+        expect(group).to respond_to(:that_thing)
+      end
     end
 
     describe "#prepend", :if => RSpec::Support::RubyFeatures.module_prepends_supported? do
@@ -1008,6 +1039,16 @@ def metadata_hash(*args)
           group = RSpec.describe('yo') { }
           expect(group.new.foo).to eq("foobar")
         end
+
+        it "prepends the given module into each existing example group" do
+          group = RSpec.describe('yo') { }
+
+          RSpec.configure do |c|
+            c.prepend(SomeRandomMod)
+          end
+
+          expect(group.new.foo).to eq("foobar")
+        end
       end
 
       context "with a filter" do
@@ -1019,6 +1060,16 @@ def metadata_hash(*args)
           group = RSpec.describe('yo', :magic_key => :include) { }
           expect(group.new.foo).to eq("foobar")
         end
+
+        it "prepends the given module into each existing matching example group" do
+          group = RSpec.describe('yo', :magic_key => :include) { }
+
+          RSpec.configure do |c|
+            c.prepend(SomeRandomMod, :magic_key => :include)
+          end
+
+          expect(group.new.foo).to eq("foobar")
+        end
       end
 
     end

spec/rspec/core/world_spec.rb

@@ -23,6 +23,27 @@ module RSpec::Core
       end
     end
 
+    describe "#all_example_groups" do
+      it "contains all example groups from all levels of nesting" do
+        RSpec.describe "eg1" do
+          context "eg2" do
+            context "eg3"
+            context "eg4"
+          end
+
+          context "eg5"
+        end
+
+        RSpec.describe "eg6" do
+          example
+        end
+
+        expect(RSpec.world.all_example_groups.map(&:description)).to match_array(%w[
+          eg1 eg2 eg3 eg4 eg5 eg6
+        ])
+      end
+    end
+
     describe "#all_examples" do
       it "contains all examples from all levels of nesting" do
         RSpec.describe do