Rails server hangs when a User method I created is called. No errors and I don't know how to test it

I call this method (with helper method detailed below as well), defined in User.rb model

def get_random_items
return nil unless groups_as_member
if groups_as_开发者_StackOverflow中文版member == 1
  assignments = groups_as_member.assignments.limit(5)
  random_items = Post.rand_by_post(assignments)
end
random_groups = groups_as_member.sort_by{rand}.slice(0,5)
random_items = Array.new
i=0
return unless random_groups
until i == 10 do
  random_groups.each do |group|
    assignments = group.assignments.limit(5)
    if y = Post.rand_by_post(assignments)
      random_items << y
      i+=1
      if random_items == 5
        return random_items
      end
    else
      return random_items
    end
  end
end

return random_items
end

helper method rand_by_post in Post.rb

def self.rand_by_post(assignments)
  find_by_id(assignments.rand.post_id)
end

in the user controller show action:

def show
@public_groups = Group.public
@groups_member = @user.groups_as_member
@groups_as_owner = @user.groups_as_owner

@random_items = @user.get_random_items
end

when I comment out the call in the user show action, the user show works fine on my development and production server. But when I try to user the method the servers will just hang there, not doing anything. I can't find any errors in the server logs or the heroku logs. My test writing skills are pretty limited, and I am having trouble writing one for the entire method. Can anyone spot a problem?

if your random_groups is empty, your helper method get_random_items will go into an endless loop until i == 10 do ... end. That could be the reason.

You might want to change return unless random_groups to return if random_groups.empty?