[Installer] Extract run_prepare_command in own controller class

lib/cocoapods/downloader/cache.rb

@@ -188,6 +188,7 @@ module Pod
         end
         destination.parent.mkpath
         FileUtils.cp_r(source, destination)
+        Pod::Installer::PodSourcePreparer.new(spec, destination).prepare!
         Sandbox::PodDirCleaner.new(destination, specs_by_platform).clean!
       end
 

lib/cocoapods/installer.rb

@@ -34,6 +34,7 @@ module Pod
     autoload :HooksContext,             'cocoapods/installer/hooks_context'
     autoload :Migrator,                 'cocoapods/installer/migrator'
     autoload :PodSourceInstaller,       'cocoapods/installer/pod_source_installer'
+    autoload :PodSourcePreparer,        'cocoapods/installer/pod_source_preparer'
     autoload :PodTargetInstaller,       'cocoapods/installer/target_installer/pod_target_installer'
     autoload :TargetInstaller,          'cocoapods/installer/target_installer'
     autoload :UserProjectIntegrator,    'cocoapods/installer/user_project_integrator'

lib/cocoapods/installer/pod_source_installer.rb

@@ -43,7 +43,7 @@ module Pod
       #
       def install!
         download_source unless predownloaded? || local?
-        run_prepare_command
+        PodSourcePreparer.new(root_spec, root).prepare! if local?
         lock_files!
       end
 
@@ -109,29 +109,6 @@ module Pod
         end
       end
 
-      extend Executable
-      executable :bash
-
-      # Runs the prepare command bash script of the spec.
-      #
-      # @note   Unsets the `CDPATH` env variable before running the
-      #         shell script to avoid issues with relative paths
-      #         (issue #1694).
-      #
-      # @return [void]
-      #
-      def run_prepare_command
-        return unless root_spec.prepare_command
-        UI.section(' > Running prepare command', '', 1) do
-          Dir.chdir(root) do
-            ENV.delete('CDPATH')
-            prepare_command = root_spec.prepare_command.strip_heredoc.chomp
-            full_command = "\nset -e\n" + prepare_command
-            bash!('-c', full_command)
-          end
-        end
-      end
-
       # Removes all the files not needed for the installation according to the
       # specs by platform.
       #

lib/cocoapods/installer/pod_source_preparer.rb

+module Pod
+  class Installer
+    # Controller class responsible of executing the prepare command
+    # of a single Pod.
+    #
+    class PodSourcePreparer
+      # @return [Specification] the root specification of the Pod.
+      #
+      attr_reader :spec
+
+      # @return [Pathname] the folder where the source of the Pod is located.
+      #
+      attr_reader :path
+
+      # @param [Specification] spec the root specification of the Pod.
+      # @param [Pathname] path the folder where the source of the Pod is located.
+      #
+      def initialize(spec, path)
+        raise "Given spec isn't a root spec, but must be." unless spec.root?
+        @spec = spec
+        @path = path
+      end
+
+      #-----------------------------------------------------------------------#
+
+      public
+
+      # @!group Preparation
+
+      # Executes the prepare command if there is one.
+      #
+      # @return [void]
+      #
+      def prepare!
+        run_prepare_command
+      end
+
+      #-----------------------------------------------------------------------#
+
+      private
+
+      # @!group Preparation Steps
+
+      extend Executable
+      executable :bash
+
+      # Runs the prepare command bash script of the spec.
+      #
+      # @note   Unsets the `CDPATH` env variable before running the
+      #         shell script to avoid issues with relative paths
+      #         (issue #1694).
+      #
+      # @return [void]
+      #
+      def run_prepare_command
+        return unless spec.prepare_command
+        UI.section(' > Running prepare command', '', 1) do
+          Dir.chdir(path) do
+            ENV.delete('CDPATH')
+            prepare_command = spec.prepare_command.strip_heredoc.chomp
+            full_command = "\nset -e\n" + prepare_command
+            bash!('-c', full_command)
+          end
+        end
+      end
+
+      #-----------------------------------------------------------------------#
+    end
+  end
+end

spec/unit/installer/pod_source_installer_spec.rb

@@ -67,12 +67,12 @@ module Pod
       describe 'Prepare command' do
         it 'runs the prepare command if one has been declared in the spec' do
           @spec.prepare_command = 'echo test'
-          @installer.expects(:bash!).once
+          Installer::PodSourcePreparer.any_instance.expects(:bash!).once
           @installer.install!
         end
 
         it "doesn't run the prepare command if it hasn't been declared in the spec" do
-          @installer.expects(:bash!).never
+          Installer::PodSourcePreparer.any_instance.expects(:bash!).never
           @installer.install!
         end