diff --git a/app/controllers/misc_controller.rb b/app/controllers/misc_controller.rb
index 4c88cf1..ffd4348 100644
--- a/app/controllers/misc_controller.rb
+++ b/app/controllers/misc_controller.rb
@@ -39,30 +39,39 @@ class MiscController < ApplicationController
 
     Zip::File.open(path, Zip::File::CREATE) do |zip|
       zip.get_output_stream('fluentd.log') {|f| f.puts fluentd.agent.log }
-      if ENV["FLUENTD_UI_LOG_PATH"].present?
-        zip.add("fluentd-ui.log", ENV["FLUENTD_UI_LOG_PATH"])
-      else
-        zip.add("fluentd-ui.log", Rails.root.join("log/#{Rails.env}.log"))
-      end
-      zip.get_output_stream('env.txt') do |f|
-        ENV.to_a.each do |(key, value)|
-          f.puts "#{key}=#{value}"
-        end
-      end
-      zip.get_output_stream('versions.txt') do |f|
-        f.puts "ruby: #{RUBY_DESCRIPTION}"
-        f.puts "fluentd: #{FluentdUI.fluentd_version}"
-        f.puts "fluentd-ui: #{FluentdUI::VERSION}"
-        f.puts
-        f.puts "# OS Information"
-        f.puts "uname -a: #{`uname -a`.strip}"
-      end
+      zip.add("fluentd-ui.log", log_path)
+
+      add_env_file_to(zip)
+      add_version_file_to(zip)
     end
     send_file path
   end
 
   private
 
+  def log_path
+    ENV["FLUENTD_UI_LOG_PATH"] || Rails.root.join("log/#{Rails.env}.log")
+  end
+
+  def add_env_file_to(zip)
+    zip.get_output_stream('env.txt') do |f|
+      ENV.to_a.each do |(key, value)|
+        f.puts "#{key}=#{value}"
+      end
+    end
+  end
+
+  def add_version_file_to(zip)
+    zip.get_output_stream('versions.txt') do |f|
+      f.puts "ruby: #{RUBY_DESCRIPTION}"
+      f.puts "fluentd: #{FluentdUI.fluentd_version}"
+      f.puts "fluentd-ui: #{FluentdUI::VERSION}"
+      f.puts
+      f.puts "# OS Information"
+      f.puts "uname -a: #{`uname -a`.strip}"
+    end
+  end
+
   def update!
     FluentdUiRestart.new.async.perform
   end
diff --git a/spec/controllers/misc_controller_spec.rb b/spec/controllers/misc_controller_spec.rb
new file mode 100644
index 0000000..b5a6aff
--- /dev/null
+++ b/spec/controllers/misc_controller_spec.rb
@@ -0,0 +1,68 @@
+require 'spec_helper'
+
+describe MiscController do
+  let(:instance) { Fluentd.new(id: nil, variant: "fluentd_gem", log_file: "dummy.log", pid_file: "dummy.pid", config_file: "dummy.conf") }
+
+  class DummyAagent
+    def log
+      "dummy_log_content"
+    end
+
+    def version
+      "dummy version"
+    end
+  end
+
+  let!(:dummy_agent) { DummyAagent.new }
+  let!(:fluentd_log_content) { dummy_agent.log }
+  let!(:fluentd_version) { dummy_agent.version }
+  let(:fluentd_ui_log_content) { <<-LOG.strip_heredoc }
+    log1
+    log2
+    log3
+  LOG
+
+  let!(:dummy_log_path) { "tmp/dummy.log" }
+  let!(:expand_dir) { Rails.root.join("tmp/system_info") }
+
+  before do
+    allow(controller).to receive(:current_user).and_return true
+
+    #dummy log for fluentd-ui.log
+    File.open(dummy_log_path, 'w') { |file| file.write(fluentd_ui_log_content) }
+    controller.stub(:log_path) { dummy_log_path }
+
+    instance.stub(:agent).and_return(dummy_agent)
+    Fluentd.stub(:instance).and_return(instance)
+  end
+
+  describe 'download_info' do
+    before do
+      get 'download_info'
+
+      #expand files in zip
+      Zip::File.open(Rails.root.join("tmp/system_info.zip")) do |zip_file|
+        FileUtils.mkdir_p(expand_dir)
+
+        zip_file.each do |f|
+          f_path = File.join(expand_dir, f.name)
+          zip_file.extract(f, f_path) unless File.exist?(f_path)
+        end
+      end
+    end
+
+    #remove all temp files for this spec
+    after do
+      FileUtils.rm Rails.root.join("tmp/system_info.zip")
+      FileUtils.rm_r expand_dir
+      FileUtils.rm dummy_log_path
+    end
+
+    it 'write files' do
+      expect(File.read(File.join(expand_dir, "fluentd.log"))).to eq "#{fluentd_log_content}\n"
+      expect(File.read(File.join(expand_dir, "fluentd-ui.log"))).to eq "#{fluentd_ui_log_content}"
+      expect(File.read(File.join(expand_dir, "env.txt"))).to match "RAILS_ENV=test"
+      expect(File.read(File.join(expand_dir, "versions.txt"))).to match "fluentd: #{fluentd_version}"
+    end
+  end
+end
diff --git a/spec/controllers/plugins_controller_spec.rb b/spec/controllers/plugins_controller_spec.rb
deleted file mode 100644
index 0ec233a..0000000
--- a/spec/controllers/plugins_controller_spec.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'spec_helper'
-
-describe PluginsController do
-
-end
diff --git a/spec/controllers/tutorials_controller_spec.rb b/spec/controllers/tutorials_controller_spec.rb
deleted file mode 100644
index d8db500..0000000
--- a/spec/controllers/tutorials_controller_spec.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'spec_helper'
-
-RSpec.describe TutorialsController, :type => :controller do
-
-end