Fix spec on CI, and refactor

app/models/plugin.rb

@@ -16,7 +16,7 @@ class Plugin
   def install!
     if valid? && !installed?
       if fluent_gem("install", gem_name, "-v", version)
-        File.open(gemfile, "a") do |f|
+        File.open(gemfile_path, "a") do |f|
           f.puts format_gemfile
         end
       end
@@ -27,11 +27,11 @@ class Plugin
     if valid? && installed?
       # NOTE: do not uninstall gem actually for now. because it is not necessary, and slow job
       new_gemfile = ""
-      File.open(gemfile).each_line do |line|
+      File.open(gemfile_path).each_line do |line|
         next if line.strip == format_gemfile
         new_gemfile << line
       end
-      File.open(gemfile, "w"){|f| f.write new_gemfile }
+      File.open(gemfile_path, "w"){|f| f.write new_gemfile }
     end
   end
 
@@ -46,7 +46,7 @@ class Plugin
   end
 
   def installed?
-    File.read(gemfile).lines.map(&:strip).grep(format_gemfile).present?
+    File.read(gemfile_path).lines.map(&:strip).grep(format_gemfile).present?
   end
 
   def format_gemfile
@@ -54,35 +54,36 @@ class Plugin
   end
 
   def self.gemfile_changed?
-    # if true, rails server needs to restart
-    @initial_gemfile_content != File.read(gemfile)
+    # if true, rails server needs to restart }
+    @initial_gemfile_content != File.read(gemfile_path)
   end
 
-  def self.gemfile
+  def self.gemfile_path
     if Rails.env == "test"
-      gemfile = Rails.root + "tmp/Gemfile.plugins"
+      gemfile_path = "/tmp/fluentd-ui-test-Gemfile.plugins" # can't create a file under Rails.root directory on Circle CI
     else
-      gemfile = Rails.root + "Gemfile.plugins"
+      gemfile_path = Rails.root + "Gemfile.plugins"
+    end
   end
 
-    unless File.exists?(gemfile)
-      File.open(gemfile, "w") do |f|
+  def self.pristine!
+    unless File.exists?(gemfile_path)
+      File.open(gemfile_path, "w") do |f|
         f.write "# USED BY fluentd-ui internally\n"
       end
     end
-    @initial_gemfile_content ||= File.read(gemfile)
-    gemfile
+    @initial_gemfile_content = File.read(gemfile_path)
   end
+  pristine!
 
-
-  def gemfile
-    self.class.gemfile
+  def gemfile_path
+    self.class.gemfile_path
   end
 
   private
 
   def fluent_gem(*commands)
-    unless system(*%W(bundle exec gem) + commands) # TODO: should grab stdout/stderr
+    unless system(*%W(bundle exec fluent-gem) + commands) # TODO: should grab stdout/stderr
       raise GemError, "failed command #{commands}"
     end
     true

spec/models/plugin_spec.rb

@@ -2,15 +2,24 @@ require 'spec_helper'
 
 describe Plugin do
   let(:plugin) { FactoryGirl.build(:plugin) }
+  before do
+    Kernel.stub(:system) # do not call `system('fluent-gem install ..')` on CI
+  end
+  after do
+    File.unlink Plugin.gemfile_path if File.exist?(Plugin.gemfile_path)
+    Plugin.pristine!
+  end
 
   describe "#valid?" do
     describe "gem_name" do
       subject { plugin }
       before { plugin.gem_name = gem_name }
+
       context "nil is invalid" do
         let(:gem_name) { nil }
         it { should_not be_valid }
       end
+
       context "somthing filled is valid" do
         let(:gem_name) { "foobar" }
         it { should be_valid }
@@ -20,10 +29,12 @@ describe Plugin do
     describe "version" do
       subject { plugin }
       before { plugin.version = version }
+
       context "nil is invalid" do
         let(:version) { nil }
         it { should_not be_valid }
       end
+
       context "somthing filled is valid" do
         let(:version) { "0.0.1" }
         it { should be_valid }
@@ -32,11 +43,6 @@ describe Plugin do
   end
 
   describe "#install!" do
-    before do
-      File.unlink Plugin.gemfile
-      Plugin.instance_variable_set(:@initial_gemfile_content, nil)
-    end
-
     describe "invoke fluent_gem" do
       after do
         plugin.stub(:valid?).and_return { valid }
@@ -85,13 +91,12 @@ describe Plugin do
   end
 
   describe "uninstall!" do
-    let(:installed_plugin) { FactoryGirl.build(:plugin) }
+    let(:installed_plugin) { FactoryGirl.build(:plugin, gem_name: "fluent-plugin-foobar") }
 
     before do
       installed_plugin.stub(:fluent_gem).and_return { true }
-      File.unlink Plugin.gemfile
       installed_plugin.install!
-      Plugin.instance_variable_set(:@initial_gemfile_content, nil)
+      Plugin.pristine!
     end
 
     before do