Implement showcase feature

#Closes 26

spec/input_helpers_spec.rb

@@ -199,4 +199,21 @@ describe Squib::InputHelpers do
     end
   end
 
+  context '#faceify' do
+    it 'is false on left' do
+      opts = @deck.send(:faceify, {face: :left})
+      expect(opts).to eq({ face: false })
+    end
+
+    it 'is true on right' do
+      opts = @deck.send(:faceify, {face: 'Right'})
+      expect(opts).to eq({ face: true })
+    end
+
+    it 'is false on anything else' do
+      opts = @deck.send(:faceify, {face: 'flugelhorn'})
+      expect(opts).to eq({ face: false })
+    end
+  end
+
 end

spec/samples/samples_regression_spec.rb

@@ -58,6 +58,7 @@ describe "Squib samples" do
       portrait-landscape.rb
       ranges.rb
       saves.rb
+      showcase.rb
       text_options.rb
       tgc_proofs.rb
       units.rb

spec/spec_helper.rb

@@ -69,7 +69,7 @@ def mock_cairo(strio)
   %w(save set_source_color paint restore translate rotate move_to
     update_pango_layout width height show_pango_layout rounded_rectangle
     set_line_width stroke fill set_source scale render_rsvg_handle circle
-    triangle line_to operator= show_page).each do |m|
+    triangle line_to operator= show_page clip transform mask).each do |m|
     allow(cxt).to receive(m) { |*args| strio << scrub_hex("cairo: #{m}(#{args})\n") }
   end