Addresses duplicate code in agents_controller

- Adds agents_controller_spec

app/controllers/fluentd/agents_controller.rb

@@ -2,29 +2,17 @@ class Fluentd::AgentsController < ApplicationController
   before_action :find_fluentd
 
   def start
-    if @fluentd.agent.start
-      flash[:success] = t("messages.fluentd_start_stop_delay_notice", action: t('fluentd.common.start'))
-    else
-      flash[:error] = t("messages.fluentd_start_failed", brand: fluentd_ui_title) + @fluentd.agent.log_tail(1).first
-    end
+    run_action(__method__) { @fluentd.agent.log_tail(1).first }
     redirect_to daemon_path(@fluentd), status: 303 # 303 is change HTTP Verb GET
   end
 
   def stop
-    if @fluentd.agent.stop
-      flash[:success] = t("messages.fluentd_start_stop_delay_notice", action: t('fluentd.common.stop'))
-    else
-      flash[:error] = t("messages.fluentd_stop_failed", brand: fluentd_ui_title)
-    end
+    run_action(__method__)
     redirect_to daemon_path(@fluentd), status: 303 # 303 is change HTTP Verb GET
   end
 
   def restart
-    if @fluentd.agent.restart
-      flash[:success] = t("messages.fluentd_start_stop_delay_notice", action: t('fluentd.common.restart'))
-    else
-      flash[:error] = t("messages.fluentd_restart_failed", brand: fluentd_ui_title) + @fluentd.agent.log_tail(1).first
-    end
+    run_action(__method__) { @fluentd.agent.log_tail(1).first }
     redirect_to daemon_path(@fluentd), status: 303 # 303 is change HTTP Verb GET
   end
 
@@ -32,4 +20,14 @@ class Fluentd::AgentsController < ApplicationController
     @logs = @fluentd.agent.log_tail(params[:limit]).reverse if @fluentd
     render json: @logs
   end
+
+  private
+  def run_action(action)
+    if @fluentd.agent.public_send(action)
+      flash[:success] = t("messages.fluentd_start_stop_delay_notice", action: t("fluentd.common.#{action}"))
+    else
+      flash[:error] = t("messages.fluentd_#{action}_failed", brand: fluentd_ui_title)
+      flash[:error] += yield if block_given?
+    end
+  end
 end

spec/controllers/fluentd/agents_controller_spec.rb

@@ -0,0 +1,45 @@
+require 'spec_helper'
+
+describe Fluentd::AgentsController do
+  before do
+    allow(controller).to receive(:current_user).and_return true
+    allow(controller).to receive(:find_fluentd).and_return(nil)
+    controller.instance_variable_set(:@fluentd, double(agent: @agent = double(:agent)))
+  end
+
+  describe "when the action succeeds" do
+    it "stops" do
+      expect(@agent).to receive(:stop).and_return true
+      put :stop
+    end
+
+    it "starts" do
+      expect(@agent).to receive(:start).and_return true
+      put :start
+    end
+
+    it "restarts" do
+      expect(@agent).to receive(:restart).and_return true
+      put :restart
+    end
+  end
+
+  describe "when the action does not succeed" do
+    it "stops" do
+      expect(@agent).to receive(:stop).and_return false
+      put :stop
+    end
+
+    it "starts" do
+      expect(@agent).to receive(:start).and_return false
+      expect(@agent).to receive(:log_tail).with(1).and_return ["some message"]
+      put :start
+    end
+
+    it "restarts" do
+      expect(@agent).to receive(:restart).and_return false
+      expect(@agent).to receive(:log_tail).with(1).and_return ["some message"]
+      put :restart
+    end
+  end
+end