Improve path parsing in _default_render_options

lib/rspec/rails/example/view_example_group.rb

@@ -129,14 +129,30 @@ def rendered.body
 
         def _default_render_options
           if ::Rails::VERSION::STRING >= '3.2'
-            # pluck the handler, format, and locale out of, eg, posts/index.de.html.haml
-            template, *components   = _default_file_to_render.split('.')
-            handler, format, locale = *components.reverse
-
-            render_options = { :template => template }
-            render_options[:handlers] = [handler] if handler
-            render_options[:formats] = [format.to_sym] if format
-            render_options[:locales] = [locale] if locale
+            handlers = ActionView::Template::Handlers.extensions.map { |x| Regexp.escape(x) }.join("|")
+            formats = ActionView::Template::Types.symbols.map { |x| Regexp.escape(x) }.join("|")
+            locales = "[a-z]{2}(?:-[A-Z]{2})?"
+            variants = "[^.]*"
+            path_regex = %r{
+              \A
+              (?<template>.*?)
+              (?:\.(?<locale>#{locales}))??
+              (?:\.(?<format>#{formats}))??
+              (?:\+(?<variant>#{variants}))??
+              (?:\.(?<handler>#{handlers}))?
+              \z
+            }x
+
+            # This regex should always find a match.
+            # Worst case, everything will be nil, and :template will just be
+            # the original string.
+            match = path_regex.match(_default_file_to_render)
+
+            render_options = { :template => match[:template] }
+            render_options[:handlers] = [match[:handler]] if match[:handler]
+            render_options[:formats] = [match[:format].to_sym] if match[:format]
+            render_options[:locales] = [match[:locale]] if match[:locale]
+            render_options[:variants] = [match[:variant]] if match[:variant]
 
             render_options
           else

spec/rspec/rails/example/view_example_group_spec.rb

@@ -137,17 +137,32 @@ def _assigns
           expect(view_spec.received.first).to eq([{:template => "widgets/new"},{}, nil])
         end
 
-        it "converts the filename components into render options" do
-          allow(view_spec).to receive(:_default_file_to_render) { "widgets/new.en.html.erb" }
-          view_spec.render
-
-          if ::Rails::VERSION::STRING >= '3.2'
+        if ::Rails::VERSION::STRING >= '3.2'
+          it "converts the filename components into render options" do
+            allow(view_spec).to receive(:_default_file_to_render) { "widgets/new.en.html.erb" }
+            view_spec.render
             expect(view_spec.received.first).to eq([{:template => "widgets/new", :locales=>['en'], :formats=>[:html], :handlers=>['erb']}, {}, nil])
-          else
+          end
+
+          it "converts the filename with variant into render options" do
+            allow(view_spec).to receive(:_default_file_to_render) { "widgets/new.en.html+fancy.erb" }
+            view_spec.render
+            expect(view_spec.received.first).to eq([{:template => "widgets/new", :locales=>['en'], :formats=>[:html], :handlers=>['erb'], variants: ['fancy']}, {}, nil])
+          end
+
+          it "converts the filename without format into render options" do
+            allow(view_spec).to receive(:_default_file_to_render) { "widgets/new.en.erb" }
+            view_spec.render
+            expect(view_spec.received.first).to eq([{:template => "widgets/new", :locales=>['en'], :handlers=>['erb']}, {}, nil])
+          end
+        else
+          it "uses the filename as a template" do
+            allow(view_spec).to receive(:_default_file_to_render) { "widgets/new.en.html.erb" }
+            view_spec.render
             expect(view_spec.received.first).to eq([{:template => "widgets/new.en.html.erb"}, {}, nil])
           end
         end
-      end
+    end
 
       context "given a string" do
         it "sends string as the first arg to render" do