Validate comment params

apps/web/controllers/comments/create.rb

@@ -2,12 +2,20 @@ module Web::Controllers::Comments
   class Create
     include Web::Action
 
+    params do
+      param :article_id, presence: true
+      param :author, presence: true
+      param :body, presence: true
+    end
+
     def initialize(comment_repository: Demo::CommentRepository)
       @comment_repository = comment_repository
     end
 
     def call(params)
-      @comment_repository.create(Demo::Comment.new(params))
+      if params.valid?
+        @comment_repository.create(Demo::Comment.new(params))
+      end
       redirect_to "/articles/#{params[:article_id]}"
     end
   end

spec/web/controllers/comments/create_spec.rb

@@ -21,5 +21,12 @@ module Web::Controllers::Comments
       action.call(params)
       comment_repository.verify
     end
+
+    it 'does not create a comment when a parameter is missing' do
+      action.call({})
+      assert_raises(MockExpectationError, 'create should not have been called') do
+        comment_repository.verify
+      end
+    end
   end
 end