refact

lib/domain/service/board_service.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class BoardService
+  def initialize(repo) = @repo = repo
+
+  def boards               = @repo.boards
+  def board(id)            = @repo.boards.find { |b| b.id == id }
+  def messages(id, n = 30) = @repo.last(id, n)
+  def count(id)            = @repo.count(id)
+  def total_count          = @repo.total_count
+
+  def post(board_id, username, text)
+    return :empty if text.to_s.strip.empty?
+    @repo.append(board_id, username, text.strip[0...1000])
+    :ok
+  end
+end