Delegate properly to custom Resolver instances

Gemfile

@@ -25,6 +25,11 @@ else
   gem 'rake', '~> 10.0' # rake 11 requires Ruby 1.9.3 or later
 end
 
+# Version 3 of mime-types 3 requires Ruby 2.0
+if RUBY_VERSION < '2.0.0'
+  gem 'mime-types', '< 3'
+end
+
 # Capybara versions that support RSpec 3 only support RUBY_VERSION >= 1.9.3
 if RUBY_VERSION >= '1.9.3'
   gem 'capybara', '~> 2.2.0', :require => false

example_app_generator/app/views/foo.html

@@ -0,0 +1 @@
+Static template named 'foo.html'

example_app_generator/app/views/some_templates/bar.html

@@ -0,0 +1 @@
+Static template named 'bar.html'

example_app_generator/generate_app.rb

@@ -38,6 +38,11 @@
     |  gem 'rake', '~> 10.0' # rake 11 requires Ruby 1.9.3 or later
     |end
     |
+    |# Version 3 of mime-types 3 requires Ruby 2.0
+    |if RUBY_VERSION < '2.0.0'
+    |  gem 'mime-types', '< 3'
+    |end
+    |
     |gem 'rspec-rails',
     |    :path => '#{rspec_rails_repo_path}',
     |    :groups => [:development, :test]

example_app_generator/generate_stuff.rb

@@ -14,6 +14,9 @@ def setup_tasks
 
     def final_tasks
       copy_file 'spec/verify_active_record_spec.rb'
+      copy_file 'app/views/foo.html'
+      copy_file 'app/views/some_templates/bar.html'
+      copy_file 'spec/verify_custom_renderers_spec.rb'
       copy_file 'spec/verify_fixture_warning_spec.rb'
       run('bin/rake db:migrate')
       if ::Rails::VERSION::STRING.to_f < 4.1

example_app_generator/spec/verify_custom_renderers_spec.rb

@@ -0,0 +1,159 @@
+require 'rails_helper'
+
+RSpec.describe "template rendering", :type => :controller do
+  context "without render_views" do
+    context "with the standard renderers" do
+      controller do
+        def index
+          render :template => 'foo', :layout => false
+        end
+      end
+
+      it "renders the 'foo' template" do
+        get :index
+
+        expect(response).to render_template(:foo)
+      end
+
+      it "renders an empty string" do
+        get :index
+
+        expect(response.body).to eq("")
+      end
+    end
+
+    context "with a String path prepended to the view path" do
+      controller do
+        def index
+          prepend_view_path('app/views/some_templates')
+
+          render :template => 'bar', :layout => false
+        end
+      end
+
+      it "renders the 'bar' template" do
+        get :index
+
+        expect(response).to render_template(:bar)
+      end
+
+      it "renders an empty string" do
+        get :index
+
+        expect(response.body).to eq("")
+      end
+    end
+
+    context "with a custom renderer prepended to the view path" do
+      controller do
+        def index
+          prepend_view_path(MyResolver.new)
+
+          render :template => 'baz', :layout => false
+        end
+      end
+
+      it "renders the 'baz' template" do
+        get :index
+
+        expect(response).to render_template(:baz)
+      end
+
+      it "renders an empty string" do
+        get :index
+
+        expect(response.body).to eq("")
+      end
+    end
+  end
+
+  context "with render_views enabled" do
+    render_views
+
+    context "with the standard renderers" do
+      controller do
+        def index
+          render :template => 'foo', :layout => false
+        end
+      end
+
+      it "renders the 'foo' template" do
+        get :index
+
+        expect(response).to render_template(:foo)
+      end
+
+      it "renders the contents of the template" do
+        get :index
+
+        expect(response.body).to include("Static template named 'foo.html'")
+      end
+    end
+
+    context "with a String path prepended to the view path" do
+      controller do
+        def index
+          prepend_view_path('app/views/some_templates')
+
+          render :template => 'bar', :layout => false
+        end
+      end
+
+      it "renders the 'bar' template" do
+        get :index
+
+        expect(response).to render_template(:bar)
+      end
+
+      it "renders the contents of the template" do
+        get :index
+
+        expect(response.body).to include("Static template named 'bar.html'")
+      end
+    end
+
+    context "with a custom renderer prepended to the view path" do
+      controller do
+        def index
+          prepend_view_path(MyResolver.new)
+
+          render :template => 'baz', :layout => false
+        end
+      end
+
+      it "renders the 'baz' template" do
+        get :index
+
+        expect(response).to render_template(:baz)
+      end
+
+      it "renders the contents of the template" do
+        get :index
+
+        expect(response.body).to eq("Dynamic template with path '/baz'")
+      end
+    end
+  end
+
+  class MyResolver < ActionView::Resolver
+  private
+
+    def find_templates(name, prefix = nil, partial = false, details = {}, key = nil, locals = [])
+      name.prepend("_") if partial
+      path = [prefix, name].join("/")
+      template = find_template(name, path)
+
+      [template]
+    end
+
+    def find_template(name, path)
+      ActionView::Template.new(
+        "",
+        name,
+        lambda { |_template| %("Dynamic template with path '#{_template.virtual_path}'") },
+        :virtual_path => path,
+        :format => :html
+      )
+    end
+  end
+end

lib/rspec/rails/view_rendering.rb

@@ -39,15 +39,18 @@ def render_views?
         self.class.render_views? || !controller.class.respond_to?(:view_paths)
       end
 
-      # Delegates find_all to the submitted path set and then returns templates
-      # with modified source
-      #
       # @private
-      class EmptyTemplateResolver < ::ActionView::FileSystemResolver
-      private
+      class EmptyTemplateResolver
+        def self.build(path)
+          if path.is_a?(::ActionView::Resolver)
+            ResolverDecorator.new(path)
+          else
+            FileSystemResolver.new(path)
+          end
+        end
 
-        def find_templates(*args)
-          super.map do |template|
+        def self.nullify_template_rendering(templates)
+          templates.map do |template|
             ::ActionView::Template.new(
               "",
               template.identifier,
@@ -57,6 +60,44 @@ def find_templates(*args)
             )
           end
         end
+
+        # Delegates all methods to the submitted resolver and for all methods
+        # that return a collection of `ActionView::Template` instances, return
+        # templates with modified source
+        #
+        # @private
+        class ResolverDecorator
+          def initialize(resolver)
+            @resolver = resolver
+          end
+
+          def method_missing(name, *args, &block)
+            result = @resolver.send(name, *args, &block)
+            nullify_templates(result)
+          end
+
+        private
+
+          def nullify_templates(collection)
+            return collection unless collection.is_a?(Enumerable)
+            return collection unless collection.all? { |element| element.is_a?(::ActionView::Template) }
+
+            EmptyTemplateResolver.nullify_template_rendering(collection)
+          end
+        end
+
+        # Delegates find_templates to the submitted path set and then returns
+        # templates with modified source
+        #
+        # @private
+        class FileSystemResolver < ::ActionView::FileSystemResolver
+        private
+
+          def find_templates(*args)
+            templates = super
+            EmptyTemplateResolver.nullify_template_rendering(templates)
+          end
+        end
       end
 
       # @private
@@ -81,13 +122,13 @@ def append_view_path(new_path)
       private
 
         def _path_decorator(*paths)
-          paths.map { |path| EmptyTemplateResolver.new(path) }
+          paths.map { |path| EmptyTemplateResolver.build(path) }
         end
       end
 
       # @private
       RESOLVER_CACHE = Hash.new do |hash, path|
-        hash[path] = EmptyTemplateResolver.new(path)
+        hash[path] = EmptyTemplateResolver.build(path)
       end
 
       included do

spec/rspec/rails/view_rendering_spec.rb

@@ -139,6 +139,13 @@ def example.controller
         expect(controller.view_paths.map(&:to_s)).to match_paths 'app/views', 'app/legacy_views', 'app/others', 'app/more_views'
       end
 
+      it 'supports manipulating view paths with resolvers' do
+        expect {
+          controller.prepend_view_path ActionView::Resolver.new
+          controller.append_view_path ActionView::Resolver.new
+        }.to_not raise_error
+      end
+
       def match_paths(*paths)
         eq paths.map { |path| File.expand_path path }
       end