Accept -l LAYOUT CLI option to set the layout

features/steps/output_steps.rb

@@ -24,6 +24,7 @@ options:
     -v, --version                    enable verbose mode
     -d, --debug                      enable debug mode
     -r, --require PATH               require ruby feature
+    -l, --layout LAYOUT              specify layout
   eoh
 end
 

lib/uh/wm/cli.rb

@@ -63,6 +63,10 @@ module Uh
             require feature
             @env.log "Loaded `#{feature}' ruby feature"
           end
+
+          opts.on '-l', '--layout LAYOUT', 'specify layout' do |layout|
+            @env.layout_class = self.class.const_get layout.to_sym
+          end
         end
       end
     end

lib/uh/wm/env.rb

@@ -12,7 +12,7 @@ module Uh
       def_delegator :@output, :print
 
       attr_reader   :output
-      attr_accessor :verbose, :debug
+      attr_accessor :verbose, :debug, :layout_class
 
       def initialize output
         @output = output

spec/uh/wm/cli_spec.rb

@@ -130,6 +130,15 @@ module Uh
           end
         end
 
+        context 'with layout option' do
+          let(:arguments) { %w[-l Object] }
+
+          it 'assigns the layout class in the env' do
+            cli.parse_arguments!
+            expect(cli.env.layout_class).to eq Object
+          end
+        end
+
         context 'with invalid option' do
           let(:arguments) { %w[--unknown-option] }
 

spec/uh/wm/env_spec.rb

@@ -13,6 +13,10 @@ module Uh
         expect(env).not_to be_debug
       end
 
+      it 'has no layout_class set' do
+        expect(env.layout_class).not_to be
+      end
+
       describe '#verbose?' do
         context 'when verbose mode is disabled' do
           before { env.verbose = false }