Implement all of `jpm list` with a simple text only output format

This brings over some of the initial plugin listing code from the
puppet-jenkins module

bin/jpm

@@ -3,7 +3,12 @@
 begin
   require 'jpm/cli'
 rescue LoadError => ex
-  puts "Failed to load jpm #{ex}"
+  $LOAD_PATH.unshift(File.expand_path(File.dirname(__FILE__) + '/../lib'))
+  begin
+    require 'jpm/cli'
+  rescue LoadError => ex
+    puts "Failed to load jpm #{ex}"
+  end
 end
 
 JPM::CLI.start(ARGV)

features/list.feature

@@ -25,3 +25,13 @@ Feature: List installed plugins
       """
       No plugins found
       """
+
+  Scenario: Listing with Jenkins installed with plugins
+    Given Jenkins is installed
+    And there are plugins available
+    When I run `jpm list`
+    Then the output should contain:
+      """
+       - ant (1.1)
+       - greenballs (1.0)
+      """

features/step_definitions/general_steps.rb

@@ -1,13 +1,25 @@
 Given(/^Jenkins isn't installed$/) do
-  # no op right now
-  # pending # express the regexp above with the code you wish you had
+  JPM.stub(:installed? => false)
 end
 
 Given(/^Jenkins is installed$/) do
-  pending
-  # no op right now
+  JPM.stub(:installed? => true)
 end
 
 Given(/^there are no plugins available$/) do
+  JPM.stub(:plugins => [])
 end
 
+Given(/^there are plugins available$/) do
+  JPM.stub(:has_plugins? => true)
+  JPM.stub(:plugins => [
+    {
+      :name => 'greenballs',
+      :version => '1.0'
+    },
+    {
+     :name => 'ant',
+     :version => '1.1'
+    },
+  ])
+end

features/support/env.rb

@@ -2,6 +2,7 @@ require 'rubygems'
 require 'aruba'
 require 'aruba/cucumber'
 require 'aruba/in_process'
+require 'cucumber/rspec/doubles'
 
 require 'jpm/cli'
 

lib/jpm.rb

@@ -1,2 +1,47 @@
 module JPM
+  # @return [Boolean] True if Jenkins is properly installed
+  def self.installed?
+    !self.home_dir.nil?
+  end
+
+  # @return [String] Full path to the Jenkins user's home directory
+  def self.home_dir
+    begin
+      return File.expand_path('~jenkins')
+    rescue ArgumentError => ex
+      # The Jenkins user doesn't exist!
+      return nil
+    end
+  end
+
+  # @return [String] Full path to the Jenkins user's plugin directory
+  def self.plugins_dir
+    return File.join(self.home_dir || '', 'plugins')
+  end
+
+  # @return [Boolean] True if the +plugins_dir+ exists and contents
+  def self.has_plugins?
+    # If the path isn't a valid directory, false
+    return false unless File.directory? self.plugins_dir
+    # If the directory doesn't have more than ['.', '..'] in it, false
+    return false if Dir.entries(self.plugins_dir) <= 2
+    return true
+  end
+
+  def self.plugins
+    return [] unless self.has_plugins?
+    plugins = []
+    Dir.entries(self.plugins_dir).each do |plugin|
+      # Skip useless directories
+      next if (plugin == '..')
+      next if (plugin == '.')
+
+      plugin_dir = File.join(self.plugins_dir, plugin)
+      # Without an unpacked plugin directory, we can't find a version
+      next unless File.directory?(plugin_dir)
+
+      plugins << plugin
+    end
+    return plugins
+  end
 end

lib/jpm/cli.rb

@@ -1,10 +1,24 @@
+require 'jpm'
 require 'thor'
 
 module JPM
   class CLI < Thor
     desc 'list', "List the installed Jenkins plugins"
     def list
-      say "Jenkins is not installed!"
+      if JPM.installed?
+        if JPM.has_plugins?
+          plugins = JPM.plugins.sort do |x, y|
+            x[:name] <=> y[:name]
+          end
+          plugins.each do |plugin|
+            say(" - #{plugin[:name]} (#{plugin[:version]})")
+          end
+        else
+          say 'No plugins found'
+        end
+      else
+        say "Jenkins is not installed!"
+      end
     end
   end
 end

spec/jpm_spec.rb

@@ -2,4 +2,107 @@ require 'spec_helper'
 require 'jpm'
 
 describe JPM do
+  describe '.installed?' do
+    subject { described_class.installed? }
+    before :each do
+      described_class.should_receive(:home_dir).and_return(home_dir)
+    end
+
+    context 'without Jenkins' do
+      let(:home_dir) { nil }
+      it { should be_false }
+    end
+
+    context 'with Jenkins' do
+      let(:home_dir) { '/var/lib/jenkins' }
+      it { should be_true }
+    end
+  end
+
+  describe '.home_dir' do
+    subject(:home_dir) { described_class.home_dir }
+
+    context "when a jenkins user doesn't exist" do
+      before :each do
+        File.should_receive(:expand_path).and_raise(ArgumentError)
+      end
+
+      it { should be_nil }
+    end
+
+    context 'when a jenkins user does exist' do
+      let(:home) { '/rspec/jenkins' }
+
+      before :each do
+        File.should_receive(:expand_path).and_return(home)
+      end
+
+      it { should eql home }
+    end
+  end
+
+  describe '.has_plugins?' do
+    subject(:exists) { described_class.has_plugins? }
+    before :each do
+      JPM.stub(:plugins_dir).and_call_original
+    end
+
+    context 'if jenkins does not exist' do
+      before :each do
+        JPM.stub(:home_dir).and_return(nil)
+      end
+
+      it { should be false }
+    end
+
+    context 'if jenkins exists' do
+      let(:home) { '/var/lib/jenkins' }
+      let(:dir_exists) { false }
+
+      before :each do
+        JPM.stub(:home_dir).and_return(home)
+        File.should_receive(:directory?).with(File.join(home, 'plugins')).and_return(dir_exists)
+      end
+
+      context 'and the directory exists' do
+        let(:dir_exists) { true }
+        before :each do
+          Dir.should_receive(:entries).and_return(entries)
+        end
+
+        context 'but is empty' do
+          let(:entries) { 2 }
+          it { should be false }
+        end
+
+        context 'and has plugins' do
+          let(:entries) { 3 }
+          it { should be true }
+        end
+      end
+
+      context 'and the directory does not exist' do
+        it { should be false }
+      end
+    end
+  end
+
+  describe '.plugins' do
+    subject(:plugins) { described_class.plugins }
+
+    context 'when plugins do not exist' do
+      before :each do
+        described_class.should_receive(:has_plugins?).and_return(false)
+      end
+
+      it { should be_empty }
+      it { should be_instance_of Array }
+    end
+
+    context 'when plugins exist' do
+      it 'should generate a list of plugins' do
+        pending 'This is too hard to unit test, feh.'
+      end
+    end
+  end
 end