[Outdated] Refine pod outdated to show what pod update would do

lib/cocoapods/command/outdated.rb

@@ -27,8 +27,9 @@ module Pod
           UI.puts 'No updates are available.'.yellow
         else
           UI.section 'The following updates are available:' do
-            updates.each do |(name, from_version, to_version)|
-              UI.puts "- #{name} #{from_version} -> #{to_version}"
+            updates.each do |(name, from_version, matching_version, to_version)|
+              UI.puts "- #{name} #{from_version} -> #{matching_version} " \
+                "(last version #{to_version})"
             end
           end
         end
@@ -64,7 +65,10 @@ module Pod
             pod_name = spec.root.name
             lockfile_version = lockfile.version(pod_name)
             if source_version > lockfile_version
-              [pod_name, lockfile_version, source_version]
+              matching_spec = unlocked_pods.find { |s| s.name == pod_name }
+              matching_version =
+                matching_spec ? matching_spec.version : "(unused)"
+              [pod_name, lockfile_version, matching_version, source_version]
             else
               nil
             end
@@ -72,6 +76,22 @@ module Pod
         end
       end
 
+      def unlocked_pods
+        @unlocked_pods ||= begin
+          sources = if config.podfile.sources.empty?
+                      SourcesManager.master
+                    else
+                      SourcesManager.sources(config.podfile.sources)
+                    end
+          Resolver.new(
+            config.sandbox,
+            config.podfile,
+            [],
+            sources
+          ).resolve.values.flatten
+        end
+      end
+
       def deprecated_pods
         @deprecated_pods ||= begin
           spec_sets.map(&:specification).select do |spec|

spec/functional/command/outdated_spec.rb

@@ -4,6 +4,10 @@ module Pod
   describe Command::Outdated do
     extend SpecHelper::TemporaryRepos
 
+    before do
+      Command::Outdated.any_instance.stubs(:unlocked_pods).returns([])
+    end
+
     it 'tells the user that no Podfile was found in the project dir' do
       exception = lambda { run_command('outdated', '--no-repo-update') }.should.raise Informative
       exception.message.should.include "No `Podfile' found in the project directory."