Fix params

app/commands/posts/update.rb

@@ -9,7 +9,7 @@ module Adamantium
           post = post_repo.fetch!(slug)
 
           if params.key? :replace
-            post_repo.update(post.id, {content: markdown.call(content: params[:content])})
+            post_repo.update(post.id, {content: markdown.call(content: params[:replace][:content])})
           end
 
           if params.key? :add