Introduced Pod `update`, `outdated`.

See #131, #191.

- The installer is initialized with a resolver. The resolver is responsible of
  indicating which specs must be installed/reinstalled.
- It was introduced a slight change in the format of the Podfile.lock.
- The specification set was simplified to receive and handle Pod::Dependency
  instead of Pod::Specification. With this change it also appears to be more
  robust.

A this stage it appears to be working. However the support, for external and
head dependencies is weak.

lib/cocoapods.rb

@@ -32,6 +32,7 @@ module Pod
   autoload :Executable,             'cocoapods/executable'
   autoload :Installer,              'cocoapods/installer'
   autoload :LocalPod,               'cocoapods/local_pod'
+  autoload :Lockfile,               'cocoapods/lockfile'
   autoload :Platform,               'cocoapods/platform'
   autoload :Podfile,                'cocoapods/podfile'
   autoload :Project,                'cocoapods/project'

lib/cocoapods/command.rb

@@ -6,12 +6,14 @@ module Pod
     autoload :Install,     'cocoapods/command/install'
     autoload :List,        'cocoapods/command/list'
     autoload :Linter,      'cocoapods/command/linter'
+    autoload :Outdated,    'cocoapods/command/outdated'
     autoload :Presenter,   'cocoapods/command/presenter'
     autoload :Push,        'cocoapods/command/push'
     autoload :Repo,        'cocoapods/command/repo'
     autoload :Search,      'cocoapods/command/search'
     autoload :Setup,       'cocoapods/command/setup'
     autoload :Spec,        'cocoapods/command/spec'
+    autoload :Update,      'cocoapods/command/update'
 
     class Help < Informative
       def initialize(command_class, argv)
@@ -100,12 +102,14 @@ module Pod
 
       command_class = case argv.shift_argument
       when 'install'  then Install
+      when 'list'     then List
+      when 'outdated' then Outdated
+      when 'push'     then Push
       when 'repo'     then Repo
       when 'search'   then Search
-      when 'list'    then List
       when 'setup'    then Setup
       when 'spec'     then Spec
-      when 'push'    then Push
+      when 'update'   then Update
       end
 
       if show_help || command_class.nil?

lib/cocoapods/command/install.rb

@@ -6,7 +6,7 @@ module Pod
 
     $ pod install
 
-      Downloads all dependencies defined in `Podfile' and creates an Xcode
+      Downloads all dependencies updated in `Podfile' and creates an Xcode
       Pods library project in `./Pods'.
 
       The Xcode project file should be specified in your `Podfile` like this:
@@ -50,7 +50,9 @@ module Pod
           Repo.new(ARGV.new(["update"])).run
         end
 
-        Installer.new(podfile).install!
+        sandbox = Sandbox.new(config.project_pods_root)
+        resolver = Resolver.new(podfile, config.lockfile, sandbox)
+        Installer.new(resolver).install!
       end
     end
   end

lib/cocoapods/command/linter.rb

@@ -103,7 +103,9 @@ module Pod
       def install_pod
         podfile = podfile_from_spec
         config.verbose
-        installer = Installer.new(podfile)
+        sandbox = Sandbox.new(config.project_pods_root)
+        resolver = Resolver.new(podfile, nil, sandbox)
+        installer = Installer.new(resolver)
         installer.install!
         @pod = installer.pods.find { |pod| pod.top_specification == spec }
         config.silent

lib/cocoapods/command/outdated.rb

+module Pod
+  class Command
+    class Outdated < Command
+      def self.banner
+%{Updates dependencies of a project:
+
+    $ pod outdated
+
+      Shows the dependencies that would be installed by `pod update'. }
+      end
+
+      def self.options
+        [
+          ["--no-update",    "Skip running `pod repo update` before install"],
+        ].concat(super)
+      end
+
+      def initialize(argv)
+        @update_repo             = !argv.option('--no-update')
+        super unless argv.empty?
+      end
+
+      def run
+        unless podfile = config.podfile
+          raise Informative, "No `Podfile' found in the current working directory."
+        end
+        unless lockfile = config.lockfile
+          raise Informative, "No `Podfile.lock' found in the current working directory, run `pod install'."
+        end
+
+        # if @update_repo
+        #   print_title 'Updating Spec Repositories', true
+        #   Re"o.new(ARGV.new(["update"])).run
+        # end
+
+        sandbox = Sandbox.new(config.project_pods_root)
+        resolver = Resolver.new(podfile, lockfile, sandbox)
+        resolver.update_mode = true
+        resolver.resolve
+        specs_to_install = resolver.specs_to_install
+        if specs_to_install.empty?
+          puts "\nNo updates are available.\n".yellow
+        else
+          puts "\nThe following updates are available:".green
+          puts "  - " << specs_to_install.join("\n  - ") << "\n\n"
+        end
+      end
+    end
+  end
+end
+
+

lib/cocoapods/command/update.rb

+module Pod
+  class Command
+    class Update < Command
+      def self.banner
+%{Updates dependencies of a project:
+
+    $ pod update
+
+      Updates all dependencies installed by `pod install`. It doesn't
+      install new dependencies. }
+      end
+
+      def self.options
+        [
+          ["--no-clean",     "Leave SCM dirs like `.git' and `.svn' intact after downloading"],
+          ["--no-doc",       "Skip documentation generation with appledoc"],
+          ["--no-integrate", "Skip integration of the Pods libraries in the Xcode project(s)"],
+          ["--no-update",    "Skip running `pod repo update` before install"],
+        ].concat(super)
+      end
+
+      def initialize(argv)
+        config.clean             = !argv.option('--no-clean')
+        config.generate_docs     = !argv.option('--no-doc')
+        config.integrate_targets = !argv.option('--no-integrate')
+        @update_repo             = !argv.option('--no-update')
+        super unless argv.empty?
+      end
+
+      def run
+        unless podfile = config.podfile
+          raise Informative, "No `Podfile' found in the current working directory."
+        end
+        unless lockfile = config.lockfile
+          raise Informative, "No `Podfile.lock' found in the current working directory, run `pod install'."
+        end
+
+        # if @update_repo
+        #   print_title 'Updating Spec Repositories', true
+        #   Repo.new(ARGV.new(["update"])).run
+        # end
+
+        sandbox = Sandbox.new(config.project_pods_root)
+        resolver = Resolver.new(podfile, lockfile, sandbox)
+        resolver.update_mode = true
+        Installer.new(resolver).install!
+      end
+    end
+  end
+end
+

lib/cocoapods/config.rb

@@ -41,6 +41,10 @@ module Pod
       @project_podfile ||= project_root + 'Podfile'
     end
 
+    def project_lockfile
+      @project_lockfile ||= project_root + 'Podfile.lock'
+    end
+
     def headers_symlink_root
       @headers_symlink_root ||= "#{project_pods_root}/Headers"
     end
@@ -53,6 +57,12 @@ module Pod
     end
     attr_writer :podfile
 
+    def lockfile
+      @lockfile ||= begin
+        Lockfile.from_file(project_lockfile) if project_lockfile.exist?
+      end
+    end
+
     module Mixin
       def config
         Config.instance

lib/cocoapods/installer.rb

@@ -7,19 +7,12 @@ module Pod
 
     include Config::Mixin
 
-    attr_reader :sandbox
+    attr_reader :resolver, :sandbox, :lockfile
 
-    def initialize(podfile)
-      @podfile = podfile
-      # FIXME: pass this into the installer as a parameter
-      @sandbox = Sandbox.new(config.project_pods_root)
-      @resolver = Resolver.new(@podfile, @sandbox)
-      # TODO: remove in 0.7 (legacy support for config.ios? and config.osx?)
-      config.podfile = podfile
-    end
-
-    def lock_file
-      config.project_root + 'Podfile.lock'
+    def initialize(resolver)
+      @resolver = resolver
+      @podfile = resolver.podfile
+      @sandbox = resolver.sandbox
     end
 
     def project
@@ -46,6 +39,9 @@ module Pod
 
     def install_dependencies!
       pods.each do |pod|
+        name = pod.top_specification.name
+        should_install = @resolver.should_install?(name)  || !pod.exists?
+
         unless config.silent?
           marker = config.verbose ? "\n-> ".green : ''
           if subspec_name = pod.top_specification.preferred_dependency
@@ -54,11 +50,12 @@ module Pod
             name = pod.to_s
           end
           name << " [HEAD]" if pod.top_specification.version.head?
-          puts marker << ( pod.exists? ? "Using #{name}" : "Installing #{name}".green )
+          puts marker << ( should_install ?  "Installing #{name}".green : "Using #{name}" )
         end
 
-        download_pod(pod) unless pod.exists?
-
+        if should_install
+          pod.implode
+          download_pod(pod)
           # This will not happen if the pod existed before we started the install
           # process.
           if pod.downloaded?
@@ -71,6 +68,7 @@ module Pod
           end
         end
       end
+    end
 
     def download_pod(pod)
       downloader = Downloader.for_pod(pod)
@@ -117,8 +115,6 @@ module Pod
         generate_dummy_source(target_installer)
       end
 
-      generate_lock_file!(specifications)
-
       puts "- Running post install hooks" if config.verbose?
       # Post install hooks run _before_ saving of project, so that they can alter it before saving.
       run_post_install_hooks
@@ -126,6 +122,10 @@ module Pod
       puts "- Writing Xcode project file to `#{@sandbox.project_path}'\n\n" if config.verbose?
       project.save_as(@sandbox.project_path)
 
+      puts "- Writing lockfile in `#{lockfile.defined_in_file}'\n\n" if config.verbose?
+      @lockfile = Lockfile.create(config.project_lockfile, @podfile, specs_by_target.values.flatten)
+      @lockfile.write_to_disk
+
       UserProjectIntegrator.new(@podfile).integrate! if config.integrate_targets?
     end
 
@@ -133,7 +133,7 @@ module Pod
       # we loop over target installers instead of pods, because we yield the target installer
       # to the spec post install hook.
       target_installers.each do |target_installer|
-        specs_by_target[target_installer.target_definition].each do |spec|
+        @specs_by_target[target_installer.target_definition].each do |spec|
           spec.post_install(target_installer)
         end
       end
@@ -141,44 +141,6 @@ module Pod
       @podfile.post_install!(self)
     end
 
-    def generate_lock_file!(specs)
-      lock_file.open('w') do |file|
-        file.puts "PODS:"
-
-        # Get list of [name, dependencies] pairs.
-        pod_and_deps = specs.map do |spec|
-          [spec.to_s, spec.dependencies.map(&:to_s).sort]
-        end.uniq
-
-        # Merge dependencies of ios and osx version of the same pod.
-        tmp = {}
-        pod_and_deps.each do |name, deps|
-          if tmp[name]
-            tmp[name].concat(deps).uniq!
-          else
-            tmp[name] = deps
-          end
-        end
-        pod_and_deps = tmp
-
-        # Sort by name and print
-        pod_and_deps.sort_by(&:first).each do |name, deps|
-          if deps.empty?
-            file.puts "  - #{name}"
-          else
-            file.puts "  - #{name}:"
-            deps.each { |dep| file.puts "    - #{dep}" }
-          end
-        end
-
-        file.puts
-        file.puts "DEPENDENCIES:"
-        @podfile.dependencies.map(&:to_s).sort.each do |dep|
-          file.puts "  - #{dep}"
-        end
-      end
-    end
-
     def generate_dummy_source(target_installer)
       class_name_identifier = target_installer.target_definition.label
       dummy_source = Generator::DummySource.new(class_name_identifier)
@@ -192,15 +154,6 @@ module Pod
       target_installer.target.source_build_phases.first << project_file
     end
 
-    def specs_by_target
-      @specs_by_target ||= @resolver.resolve
-    end
-
-    # @return [Array<Specification>]  All dependencies that have been resolved.
-    def specifications
-      specs_by_target.values.flatten
-    end
-
     # @return [Array<LocalPod>]  A list of LocalPod instances for each
     #                            dependency that is not a download-only one.
     def pods
@@ -219,6 +172,14 @@ module Pod
       result
     end
 
+    def specifications
+      specs_by_target.values.flatten
+    end
+
+    def specs_by_target
+      @specs_by_target ||= @resolver.resolve
+    end
+
     private
 
     def print_title(title, only_verbose = true)

lib/cocoapods/lockfile.rb

+module Pod
+  class Lockfile
+
+    # @return [Lockfile] Returns the Lockfile saved in path.
+    #
+    def self.from_file(path)
+      Lockfile.new(path)
+    end
+
+    # @return [Lockfile] Creates a new Lockfile ready to be saved in path.
+    #
+    def self.create(path, podfile, specs)
+      Lockfile.new(path, podfile, specs)
+    end
+
+    attr_reader :defined_in_file, :podfile, :specs, :dictionary_reppresenation
+
+    # @param [Pathname] the path of the Lockfile.
+    #   If no other value is provided the Lockfile is read from this path.
+    # @param [Podfile] the Podfile to use for generating the Lockfile.
+    # @param [specs] the specs installed.
+    #
+    def initialize(path, podfile = nil, specs = nil)
+      @defined_in_file = path
+      if podfile && specs
+        @podfile = podfile
+        @specs = specs
+      else
+        yaml = YAML.load(File.open(path))
+        if yaml && Version.new(yaml["COCOAPODS"]) >= Version.new("0.10")
+          @dictionary_reppresenation = yaml
+        end
+      end
+    end
+
+    # @return [Array<Dependency>] The dependencies used during the last install.
+    #
+    def podfile_dependencies
+      return [] unless to_dict
+      dependencies = to_dict['DEPENDENCIES'] | []
+      dependencies.map { |dep|
+        match_data = dep.match(/(\S*)( (.*))/)
+        Dependency.new(match_data[1], match_data[2].gsub(/[()]/,''))
+      }
+    end
+
+    # @return [Array<Dependency>] The dependencies that require exactly,
+    #   the installed pods.
+    #
+    def installed_dependencies
+      return [] unless to_dict
+      pods = to_dict['PODS'] | []
+      pods.map { |pod|
+        name_and_version = pod.is_a?(String) ? pod : pod.keys[0]
+        match_data = name_and_version.match(/(\S*)( (.*))/)
+        Dependency.new(match_data[1], match_data[2].gsub(/[()]/,''))
+      }
+    end
+
+    # @return [void] Writes the Lockfile to path.
+    #
+    def write_to_disk
+      File.open(defined_in_file, 'w') {|f| f.write(to_yaml) }
+    end
+
+    # @return [String] A string useful to represent the Lockfile in a message
+    #   presented to the user.
+    #
+    def to_s
+      "Podfile.lock"
+    end
+
+    # @return [String] The YAML representation of the Lockfile, used for
+    #   serialization.
+    #
+    def to_yaml
+      to_dict.to_yaml
+    end
+
+    # @return [Dictionary] The Dictionary representation of the Lockfile.
+    #
+    def to_dict
+      return @dictionary_reppresenation if @dictionary_reppresenation
+      return nil unless @podfile && @specs
+
+      # Get list of [name, dependencies] pairs.
+      pod_and_deps = specs.map do |spec|
+        [spec.to_s, spec.dependencies.map(&:to_s).sort]
+      end.uniq
+
+      # Merge dependencies of ios and osx version of the same pod.
+      tmp = {}
+      pod_and_deps.each do |name, deps|
+        if tmp[name]
+          tmp[name].concat(deps).uniq!
+        else
+          tmp[name] = deps
+        end
+      end
+      pod_and_deps = tmp.sort_by(&:first).map do |name, deps|
+        deps.empty? ? name : {name => deps}
+      end
+
+      dict = {}
+      dict["PODS"] = pod_and_deps
+      dict["DEPENDENCIES"] = podfile.dependencies.map(&:to_s).sort
+      # dict["SPECS_CHECKSUM"] =
+      # dict["HEAD_SPECS_INFO"] =
+      dict["COCOAPODS"] = VERSION
+      dict
+    end
+  end
+end
+

lib/cocoapods/resolver.rb

@@ -4,34 +4,111 @@ module Pod
   class Resolver
     include Config::Mixin
 
-    attr_reader :podfile, :sandbox
-    attr_accessor :cached_sets, :cached_sources
+    attr_reader :podfile, :lockfile, :sandbox
+    attr_accessor :cached_sets, :cached_sources, :update_mode
 
-    def initialize(podfile, sandbox)
+    def initialize(podfile, lockfile, sandbox)
       @podfile  = podfile
+      @lockfile = lockfile
       @sandbox  = sandbox
       @cached_sets = {}
       @cached_sources = Source::Aggregate.new
       @log_indent = 0;
+
+    end
+
+    def installed_dependencies
+      @installed_dependencies ||= lockfile ? lockfile.installed_dependencies : []
+    end
+
+    def should_install?(name)
+      names_of_pods_installs = specs_to_install.map(&:name)
+      names_of_pods_installs.include?(name)
+    end
+
+    def specs_to_install
+      if update_mode
+        specs = @targets_and_specs.values.flatten
+        outdated_specs = []
+        specs.each do |spec|
+          if spec_outdated?(spec)
+            outdated_specs << spec
+          end
+        end
+        outdated_specs
+      else
+        specs = @targets_and_specs.values.flatten
+        outdated_specs = []
+        specs.each do |spec|
+          unless spec_installed?(spec)
+            outdated_specs << spec
+          end
+        end
+        outdated_specs
+        # Implement this forces the installer to install only the specs that don't have a folder.
+        # Should install also if there was a change in the podfile
+        # Disambiguate dependecies before resolution?
+        []
+      end
+    end
+
+    def specs_by_target
+      @targets_and_specs
     end
 
     def resolve
+      if lockfile
+        if config.verbose?
+          puts "\nInstalled podfile dependencies detected in: #{lockfile.defined_in_file}".green
+          lockfile.podfile_dependencies.each {|dependency| puts "  - #{dependency}" }
+          puts "\nInstalled pods versions detected in: #{lockfile.defined_in_file}".green
+          lockfile.installed_dependencies.each {|dependency| puts "  - #{dependency}" }
+        end
+      end
+
+      unless update_mode || !lockfile
+        puts "\nLocking dependencies to installed versions:".green if config.verbose?
+        # Add the installed specs which are still compatible with podfile
+        # requirements to activated
+        installed_dependencies.each do |dependency|
+          compatible_with_podfile = dependency && true
+          if compatible_with_podfile
+            puts "  - #{dependency}" if config.verbose?
+            set = find_cached_set(dependency, nil)
+            set.required_by(dependency, lockfile.to_s)
+          end
+        end
+      end
+
       @specs = {}
-      targets_and_specs = {}
+      @targets_and_specs = {}
 
       @podfile.target_definitions.values.each do |target_definition|
         puts "\nResolving dependencies for target `#{target_definition.name}' (#{target_definition.platform})".green if config.verbose?
         @loaded_specs = []
         find_dependency_specs(@podfile, target_definition.dependencies, target_definition)
-        targets_and_specs[target_definition] = @specs.values_at(*@loaded_specs).sort_by(&:name)
+        @targets_and_specs[target_definition] = @specs.values_at(*@loaded_specs).sort_by(&:name)
       end
 
       @specs.values.sort_by(&:name)
-      targets_and_specs
+      @targets_and_specs
     end
 
     private
 
+    def dependency_installed?(dependency)
+      installed_dependencies.any?{ |installed_dependency| installed_dependency.name == dependency.name }
+    end
+
+    def spec_installed?(spec)
+      installed_dependencies.any?{ |installed_dependency| installed_dependency.name == spec.name }
+    end
+
+    def spec_outdated?(spec)
+      installed_dependency = installed_dependencies.find{|installed_dependency| installed_dependency.name == spec.name }
+      installed_dependency && !installed_dependency.matches_spec?(spec)
+    end
+
     def find_cached_set(dependency, platform)
       set_name = dependency.name.split('/').first
       @cached_sets[set_name] ||= begin
@@ -58,9 +135,16 @@ module Pod
       dependencies.each do |dependency|
         puts '  ' * @log_indent + "- #{dependency}" if config.verbose?
         set = find_cached_set(dependency, target_definition.platform)
-        set.required_by(dependent_specification)
+        set.required_by(dependency, dependent_specification.to_s)
+
+        if update_mode
+          mode_wants_spec = dependency_installed?(dependency)
+        else
+          mode_wants_spec = true
+        end
+
         # Ensure we don't resolve the same spec twice for one target
-        unless @loaded_specs.include?(dependency.name)
+        if mode_wants_spec && !@loaded_specs.include?(dependency.name)
           spec = set.specification_by_name(dependency.name)
           @loaded_specs << spec.name
           @specs[spec.name] = spec
@@ -69,9 +153,9 @@ module Pod
           spec.version.head = dependency.head?
           # And recursively load the dependencies of the spec.
           find_dependency_specs(spec, spec.dependencies, target_definition) if spec.dependencies
-        end
           validate_platform!(spec || @specs[dependency.name], target_definition)
         end
+      end
       @log_indent -= 1
     end
 

lib/cocoapods/specification/set.rb

@@ -6,22 +6,18 @@ module Pod
       def initialize(pod_dir)
         @pod_dir = pod_dir
         @required_by = []
+        @dependencies = []
       end
 
-      def required_by(specification)
-        # Skip subspecs because the can't require a different version of the top level parent
-        return if !specification.podfile? && specification.top_level_parent.name == name
-
-        dependency = specification.dependency_by_top_level_spec_name(name)
-        # TODO we don’t actually do anything in our Version subclass. Maybe we should just remove that.
+      def required_by(dependency, dependent_name)
         unless @required_by.empty? || dependency.requirement.satisfied_by?(Gem::Version.new(required_version.to_s))
-          # TODO add graph that shows which dependencies led to this.
-          raise Informative, "#{specification} tries to activate `#{dependency}', " \
+          raise Informative, "#{dependent_name} tries to activate `#{dependency}', " \
                              "but already activated version `#{required_version}' " \
                              "by #{@required_by.join(', ')}."
         end
         @specification = nil
-        @required_by << specification
+        @required_by << dependent_name
+        @dependencies << dependency
       end
 
       def specification_by_name(name)
@@ -29,8 +25,8 @@ module Pod
       end
 
       def dependency
-        @required_by.inject(Dependency.new(name)) do |previous, spec|
-          previous.merge(spec.dependency_by_top_level_spec_name(name).to_top_level_spec_dependency)
+        @dependencies.inject(Dependency.new(name)) do |previous, dependency|
+          previous.merge(dependency.to_top_level_spec_dependency)
         end
       end
 
@@ -74,6 +70,7 @@ module Pod
         def initialize(specification)
           @specification = specification
           @required_by = []
+          @dependencies = []
         end
 
         def name
@@ -84,9 +81,9 @@ module Pod
           self.class === other && name == other.name
         end
 
-        def required_by(specification)
+        def required_by(dependency, dependent_name)
           before = @specification
-          super(specification)
+          super(dependency, dependent_name)
         ensure
           @specification = before
         end

spec/functional/command/outdated_spec.rb

+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe Pod::Command::Outdated do
+  extend SpecHelper::Command
+  extend SpecHelper::TemporaryDirectory
+  extend SpecHelper::TemporaryRepos
+
+  it "tells the user that no Podfile was found in the current working dir" do
+    exception = lambda { run_command('outdated','--no-update') }.should.raise Pod::Informative
+    exception.message.should.include "No `Podfile' found in the current working directory."
+  end
+
+  it "tells the user that no Lockfile was found in the current working dir" do
+    file = temporary_directory + 'Podfile'
+    File.open(file, 'w') {|f| f.write('platform :ios') }
+    Dir.chdir(temporary_directory) do
+      exception = lambda { run_command('outdated','--no-update') }.should.raise Pod::Informative
+      exception.message.should.include "No `Podfile.lock' found in the current working directory"
+    end
+  end
+end
+

spec/functional/command/update_spec.rb

+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe Pod::Command::Update do
+  extend SpecHelper::Command
+  extend SpecHelper::TemporaryDirectory
+  extend SpecHelper::TemporaryRepos
+
+  it "tells the user that no Podfile was found in the current working dir" do
+    exception = lambda { run_command('update','--no-update') }.should.raise Pod::Informative
+    exception.message.should.include "No `Podfile' found in the current working directory."
+  end
+
+  it "tells the user that no Lockfile was found in the current working dir" do
+    file = temporary_directory + 'Podfile'
+    File.open(file, 'w') {|f| f.write('platform :ios') }
+    Dir.chdir(temporary_directory) do
+      exception = lambda { run_command('update','--no-update') }.should.raise Pod::Informative
+      exception.message.should.include "No `Podfile.lock' found in the current working directory"
+    end
+  end
+end
+

spec/integration_spec.rb

@@ -70,10 +70,12 @@ else
           end
 
           # Note that we are *not* using the stubbed SpecHelper::Installer subclass.
-          installer = Pod::Installer.new(podfile)
+
+          resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = Pod::Installer.new(resolver)
           installer.install!
 
-          YAML.load(installer.lock_file.read).should == {
+          installer.lockfile.to_dict.tap {|d| d.delete("COCOAPODS") }.should == {
             'PODS' => ['SSToolkit (0.1.3)'],
             'DEPENDENCIES' => ["SSToolkit (from `#{url}', commit `#{commit}')"]
           }
@@ -88,10 +90,12 @@ else
             pod 'Reachability', :podspec => url
           end
 
-          installer = SpecHelper::Installer.new(podfile)
+
+          resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = SpecHelper::Installer.new(resolver)
           installer.install!
 
-          YAML.load(installer.lock_file.read).should == {
+          installer.lockfile.to_dict.tap {|d| d.delete("COCOAPODS") }.should == {
             'PODS' => [ 'Reachability (1.2.3)' ],
             # 'DOWNLOAD_ONLY' => ["ASIHTTPRequest (1.8.1)"],
             'DEPENDENCIES' => ["Reachability (from `#{url}')"]
@@ -111,7 +115,8 @@ else
             end
           end
 
-          installer = SpecHelper::Installer.new(podfile)
+          resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = SpecHelper::Installer.new(resolver)
           installer.install!
 
           dummy = (config.project_pods_root + 'PodsDummy_Pods.m').read
@@ -134,7 +139,8 @@ else
             end
           end
 
-          installer = SpecHelper::Installer.new(podfile)
+          resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = SpecHelper::Installer.new(resolver)
           installer.install!
 
           dummy = (config.project_pods_root + 'PodsDummy_Pods_AnotherTarget.m').read
@@ -160,10 +166,11 @@ else
           end
 
           Pod::Specification.any_instance.stubs(:preserve_paths).returns(['CHANGELOG.md'])
-          installer = SpecHelper::Installer.new(podfile)
+          resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = SpecHelper::Installer.new(resolver)
           installer.install!
 
-          YAML.load(installer.lock_file.read).should == {
+          installer.lockfile.to_dict.tap {|d| d.delete("COCOAPODS") }.should == {
             'PODS' => ['JSONKit (1.2)', 'SSZipArchive (0.1.0)'],
             'DEPENDENCIES' => ["JSONKit (defined in Podfile)", "SSZipArchive (defined in Podfile)"]
           }
@@ -188,11 +195,12 @@ else
             end
           end
 
-          installer = SpecHelper::Installer.new(podfile)
+          resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = SpecHelper::Installer.new(resolver)
           installer.install!
 
           # TODO might be nicer looking to not show the dependencies of the top level spec for each subspec (Reachability).
-          YAML.load(installer.lock_file.read).should == {
+          installer.lockfile.to_dict.should == {
             "PODS" => [{ "ASIHTTPRequest (1.8.1)" => ["ASIHTTPRequest/ASIWebPageRequest (= 1.8.1)",
                                                       "ASIHTTPRequest/CloudFiles (= 1.8.1)",
                                                       "ASIHTTPRequest/S3 (= 1.8.1)",
@@ -201,7 +209,8 @@ else
                        { "ASIHTTPRequest/CloudFiles (1.8.1)" => ["Reachability"] },
                        { "ASIHTTPRequest/S3 (1.8.1)" => ["Reachability"] },
                        "JSONKit (1.4)", "Reachability (3.0.0)"],
-            "DEPENDENCIES" => ["ASIHTTPRequest", "JSONKit (= 1.4)"]
+            "DEPENDENCIES" => ["ASIHTTPRequest", "JSONKit (= 1.4)"],
+            "COCOAPODS" => Pod::VERSION
           }
 
           should_xcodebuild(podfile.target_definitions[:ios_target])
@@ -227,7 +236,8 @@ else
               pod 'JSONKit', '1.4'
               pod 'SSToolkit', '1.0.0'
             end
-            installer = SpecHelper::Installer.new(podfile)
+            resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+            installer = SpecHelper::Installer.new(resolver)
             installer.install!
 
             doc = (config.project_pods_root + 'Documentation/JSONKit/html/index.html').read
@@ -258,7 +268,8 @@ else
           end
         end
 
-        SpecHelper::Installer.new(podfile).install!
+        resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+        SpecHelper::Installer.new(resolver).install!
         project = Pod::Project.new(config.project_pods_root + 'Pods.xcodeproj')
         project.targets.first.build_configurations.map do |config|
           config.build_settings['GCC_ENABLE_OBJC_GC']
@@ -277,10 +288,11 @@ else
           pod 'SSZipArchive',      '< 2'
         end
 
-        installer = SpecHelper::Installer.new(podfile)
+        resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = SpecHelper::Installer.new(resolver)
         installer.install!
 
-        lock_file_contents = {
+        lockfile_contents = {
           'PODS' => [
             # { 'ASIHTTPRequest (1.8.1)'    => ["Reachability"] },
             # { 'ASIWebPageRequest (1.8.1)' => ["ASIHTTPRequest (= 1.8.1)"] },
@@ -293,15 +305,16 @@ else
             "JSONKit (>= 1.0)",
             "Reachability (> 2.0.5)",
             "SSZipArchive (< 2)",
-          ]
+          ],
+          "COCOAPODS" => Pod::VERSION
         }
         unless platform == :ios
           # No Reachability is required by ASIHTTPRequest on OSX
-          lock_file_contents['DEPENDENCIES'].delete_at(1)
-          lock_file_contents['PODS'].delete_at(1)
-          # lock_file_contents['PODS'][0] = 'ASIHTTPRequest (1.8.1)'
+          lockfile_contents['DEPENDENCIES'].delete_at(1)
+          lockfile_contents['PODS'].delete_at(1)
+          # lockfile_contents['PODS'][0] = 'ASIHTTPRequest (1.8.1)'
         end
-        YAML.load(installer.lock_file.read).should == lock_file_contents
+        installer.lockfile.to_dict.should == lockfile_contents
 
         root = config.project_pods_root
         (root + 'Pods.xcconfig').read.should == installer.target_installers.first.xcconfig.to_s
@@ -320,10 +333,11 @@ else
             pod 'Reachability', '2.0.4' # only 2.0.4 is part of ASIHTTPRequest’s source.
           end
 
-          installer = SpecHelper::Installer.new(spec)
+          resolver = Pod::Resolver.new(spec, nil, Pod::Sandbox.new(config.project_pods_root))
+          installer = SpecHelper::Installer.new(resolver)
           installer.install!
 
-          YAML.load(installer.lock_file.read).should == {
+          installer.lockfile.to_dict.tap {|d| d.delete("COCOAPODS") }.should == {
             # 'PODS' => [{ 'Reachability (2.0.4)' => ["ASIHTTPRequest (>= 1.8)"] }],
             'PODS' => [ 'Reachability (2.0.4)' ],
             # 'DOWNLOAD_ONLY' => ["ASIHTTPRequest (1.8.1)"],
@@ -339,7 +353,8 @@ else
           pod 'SSZipArchive'
         end
 
-        installer = SpecHelper::Installer.new(spec)
+        resolver = Pod::Resolver.new(spec, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = SpecHelper::Installer.new(resolver)
         target_definition = installer.target_installers.first.target_definition
         installer.specs_by_target[target_definition].first.resources = 'LICEN*', 'Readme.*'
         installer.install!
@@ -356,7 +371,8 @@ else
           xcodeproj 'dummy'
           pod 'JSONKit'
         end
-        installer = SpecHelper::Installer.new(spec)
+        resolver = Pod::Resolver.new(spec, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = SpecHelper::Installer.new(resolver)
         installer.install!
 
         spec = Pod::Podfile.new do
@@ -364,7 +380,8 @@ else
           xcodeproj 'dummy'
           pod 'SSZipArchive'
         end
-        installer = SpecHelper::Installer.new(spec)
+        resolver = Pod::Resolver.new(spec, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = SpecHelper::Installer.new(resolver)
         installer.install!
 
         project = Pod::Project.new(config.project_pods_root + 'Pods.xcodeproj')
@@ -380,7 +397,9 @@ else
           pod 'ASIHTTPRequest'
         end
 
-        installer = Pod::Installer.new(podfile)
+        resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(fixture('integration')))
+        resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = Pod::Installer.new(resolver)
         installer.install!
 
         project = Xcodeproj::Project.new(config.project_pods_root + 'Pods.xcodeproj')
@@ -431,7 +450,8 @@ else
           pod 'SSZipArchive'
         end
 
-        installer = SpecHelper::Installer.new(podfile)
+        resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = SpecHelper::Installer.new(resolver)
         installer.install!
 
         workspace = Xcodeproj::Workspace.new_from_xcworkspace(temporary_directory + 'ASIHTTPRequest.xcworkspace')
@@ -458,7 +478,8 @@ else
           pod 'ASIHTTPRequest'
         end
 
-        installer = Pod::Installer.new(podfile)
+        resolver = Pod::Resolver.new(podfile, nil, Pod::Sandbox.new(config.project_pods_root))
+        installer = Pod::Installer.new(resolver)
         installer.install!
 
         root = config.project_pods_root

spec/unit/installer_spec.rb

@@ -14,7 +14,10 @@ module Pod
           xcodeproj 'MyProject'
           pod 'JSONKit'
         end
-        @xcconfig = Installer.new(podfile).target_installers.first.xcconfig.to_hash
+
+        sandbox = Sandbox.new(fixture('integration'))
+        resolver = Resolver.new(podfile, nil, sandbox)
+        @xcconfig = Installer.new(resolver).target_installers.first.xcconfig.to_hash
       end
 
       it "sets the header search paths where installed Pod headers can be found" do
@@ -35,7 +38,10 @@ module Pod
         platform :osx
         pod 'ASIHTTPRequest'
       end
-      installer = Installer.new(podfile)
+
+      sandbox = Sandbox.new(fixture('integration'))
+      resolver = Resolver.new(podfile, nil, sandbox)
+      installer = Installer.new(resolver)
       pods = installer.specifications.map do |spec|
         LocalPod.new(spec, installer.sandbox, podfile.target_definitions[:default].platform)
       end
@@ -51,7 +57,8 @@ module Pod
           pod 'JSONKit'
         end
       end
-      installer = Installer.new(podfile)
+      resolver = Resolver.new(podfile, nil, Sandbox.new(fixture('integration')))
+      installer = Installer.new(resolver)
       installer.target_installers.map(&:target_definition).map(&:name).should == [:not_empty]
     end
 
@@ -61,7 +68,8 @@ module Pod
         platform :ios
         xcodeproj path, 'App Store' => :release
       end
-      installer = Installer.new(podfile)
+      resolver = Resolver.new(podfile, nil, Sandbox.new(fixture('integration')))
+      installer = Installer.new(resolver)
       installer.project.build_configurations.map(&:name).sort.should == ['App Store', 'Debug', 'Release', 'Test']
     end
 
@@ -70,7 +78,8 @@ module Pod
         platform :ios
         pod 'JSONKit', :head
       end
-      installer = Installer.new(podfile)
+      resolver = Resolver.new(podfile, nil, Sandbox.new(fixture('integration')))
+      installer = Installer.new(resolver)
       pod = installer.pods.first
 
       downloader = stub('Downloader')

spec/unit/lockfile_spec.rb

+require File.expand_path('../../spec_helper', __FILE__)
+
+describe "Pod::Lockfile" do
+  extend SpecHelper::TemporaryDirectory
+
+  def sample
+    text = <<-LOCKFILE.strip_heredoc
+      ---
+      PODS:
+      - BananaLib (1.0):
+        - monkey (< 1.0.9, ~> 1.0.1)
+      - monkey (1.0.8)
+      DEPENDENCIES:
+      - BananaLib (~> 1.0)
+      COCOAPODS: #{Pod::VERSION}
+      LOCKFILE
+  end
+
+  def podfile
+    Pod::Podfile.new do
+      platform :ios
+      pod 'BananaLib', '~>1.0'
+    end
+  end
+
+  def specs
+    specs = [
+      Pod::Specification.from_file(fixture('banana-lib/BananaLib.podspec')),
+      Pod::Specification.new do |s|
+        s.name = "monkey"
+        s.version = "1.0.8"
+      end
+    ]
+    specs.each { |s| s.activate_platform(:ios) }
+    specs
+  end
+
+  def tmp_path
+    temporary_directory + 'Podfile.lock'
+  end
+
+  it "loads from a file" do
+    File.open(tmp_path, 'w') {|f| f.write(sample) }
+    lockfile = Pod::Lockfile.from_file(tmp_path)
+    lockfile.defined_in_file.should == tmp_path
+    lockfile.to_yaml.should == sample
+  end
+
+  before do
+    @lockfile = Pod::Lockfile.create(tmp_path, podfile, specs)
+  end
+
+  it "generates a valid YAML representation" do
+    @lockfile.to_yaml.should == sample
+  end
+
+  it "generates a valid Dictionary representation" do
+    @lockfile.to_dict.should == YAML.load(sample)
+  end
+
+  it "returns the Podfile dependencies" do
+    @lockfile.podfile_dependencies.should == [
+      Pod::Dependency.new("BananaLib", "~> 1.0")
+    ]
+  end
+
+  it "returns the dependencies for the installed pods" do
+    @lockfile.installed_dependencies.should == [
+      Pod::Dependency.new("BananaLib", "= 1.0"),
+      Pod::Dependency.new("monkey", "= 1.0.8")
+    ]
+  end
+
+  it "can check if it is compatible with a file" do
+    File.open(tmp_path, 'w') {|f| f.write(sample.gsub("COCOAPODS: #{Pod::VERSION}", "")) }
+    lockfile = Pod::Lockfile.from_file(tmp_path)
+    lockfile.to_dict.should == nil
+  end
+
+  it "serializes correctly `:head' dependencies" do
+    podfile = Pod::Podfile.new do
+      platform :ios
+      pod 'BananaLib', :head
+    end
+    specs = [
+      Pod::Specification.new do |s|
+        s.name = "BananaLib"
+        s.version = "1.0"
+      end,
+      Pod::Specification.new do |s|
+        s.name = "monkey"
+        s.version = "1.0.8"
+      end
+    ]
+    specs.each { |s| s.activate_platform(:ios) }
+    lockfile = Pod::Lockfile.create(tmp_path, podfile, specs)
+    lockfile.to_dict["DEPENDENCIES"][0].should == "BananaLib [HEAD]"
+  end
+
+  it "serializes correctly external dependencies" do
+    podfile = Pod::Podfile.new do
+      platform :ios
+      pod 'BananaLib', :git => "www.example.com"
+    end
+    specs = [
+      Pod::Specification.new do |s|
+        s.name = "BananaLib"
+        s.version = "1.0"
+      end,
+      Pod::Specification.new do |s|
+        s.name = "monkey"
+        s.version = "1.0.8"
+      end
+    ]
+    specs.each { |s| s.activate_platform(:ios) }
+    lockfile = Pod::Lockfile.create(tmp_path, podfile, specs)
+    lockfile.to_dict["DEPENDENCIES"][0].should == "BananaLib (from `www.example.com')"
+  end
+
+  xit "reads `:heads' dependencies correctly" do
+  end
+
+  xit "reads external dependencies dependencies correctly" do
+  end
+end

spec/unit/resolver_spec.rb

@@ -10,7 +10,7 @@ module Pod
         pod 'BlocksKit'
         # pod 'ASIWebPageRequest'
       end
-      @resolver = Resolver.new(@podfile, stub('sandbox'))
+      @resolver = Resolver.new(@podfile, nil, stub('sandbox'))
     end
 
     it "holds the context state, such as cached specification sets" do
@@ -73,7 +73,7 @@ module Pod
         pod 'RestKit/Network'
         pod 'RestKit/ObjectMapping/XML'
       end
-      resolver = Resolver.new(@podfile, stub('sandbox'))
+      resolver = Resolver.new(@podfile, nil, stub('sandbox'))
       resolver.resolve.values.flatten.map(&:name).sort.should == %w{
         FileMD5Hash
         ISO8601DateFormatter
@@ -93,7 +93,7 @@ module Pod
         platform :ios
         pod 'RestKit'
       end
-      resolver = Resolver.new(@podfile, stub('sandbox'))
+      resolver = Resolver.new(@podfile, nil, stub('sandbox'))
       resolver.resolve.values.flatten.map(&:name).sort.should == %w{
         FileMD5Hash
         ISO8601DateFormatter
@@ -139,7 +139,7 @@ module Pod
           end
         end
       end
-      resolver = Resolver.new(@podfile, stub('sandbox'))
+      resolver = Resolver.new(@podfile, nil, stub('sandbox'))
       specs = resolver.resolve.values.flatten.map(&:name).sort
       specs.should.not.include 'RestKit/ObjectMapping/XML'
       specs.should == %w{
@@ -175,7 +175,7 @@ module Pod
         end
       end
       @podfile.dependencies.first.external_source.stubs(:specification_from_sandbox).returns(spec)
-      resolver = Resolver.new(@podfile, stub('sandbox'))
+      resolver = Resolver.new(@podfile, nil, stub('sandbox'))
       resolver.resolve.values.flatten.map(&:name).sort.should == %w{ MainSpec/FirstSubSpec MainSpec/FirstSubSpec/SecondSubSpec }
     end
 
@@ -185,10 +185,48 @@ module Pod
         pod 'FileMD5Hash'
         pod 'JSONKit', :head
       end
-      resolver = Resolver.new(podfile, stub('sandbox'))
+      resolver = Resolver.new(podfile, nil, stub('sandbox'))
       filemd5hash, jsonkit = resolver.resolve.values.first.sort_by(&:name)
       filemd5hash.version.should.not.be.head
       jsonkit.version.should.be.head
     end
+
+    xit "raises if it finds two conflicting dependencies" do
+
+    end
+
+    describe "Concerning the Lockfile" do
+      xit "accepts a nil lockfile" do
+        lambda { Resolver.new(@podfile, nil, stub('sandbox'))}.should.not.raise
+      end
+
+      xit "detects the pods that need to be installed" do
+
+      end
+
+      xit "detects the pods that don't need to be installed" do
+
+      end
+
+      xit "detects the pods that can be updated" do
+
+      end
+
+      xit "doesn't install new pods in `update_mode'" do
+
+      end
+
+      xit "handles correctly pods with external source" do
+
+      end
+
+      xit "it always suggest to update pods in head mode" do
+
+      end
+
+      xit "it prevents a pod from upgrading during an install" do
+
+      end
+    end
   end
 end

spec/unit/specification/set_spec.rb

@@ -14,23 +14,23 @@ describe "Pod::Specification::Set" do
   end
 
   it "checks if the dependency of the specification is compatible with existing requirements" do
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '1.2' })
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '< 1.2.1' })
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '> 1.1' })
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '~> 1.2.0' })
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack' })
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack', '1.2'), 'Spec')
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack', '< 1.2.1'), 'Spec')
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack', '> 1.1'), 'Spec')
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack', '~> 1.2.0'), 'Spec')
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack'), 'Spec')
     lambda {
-      @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '< 1.0' })
+      @set.required_by(Pod::Dependency.new('CocoaLumberjack', '< 1.0' ), 'Spec')
     }.should.raise Pod::Informative
   end
 
   it "raises if the required version doesn't exist" do
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '< 1.0' })
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack', '< 1.0'), 'Spec')
     lambda { @set.required_version }.should.raise Pod::Informative
   end
 
   before do
-    @set.required_by(Pod::Spec.new { |s| s.dependency 'CocoaLumberjack', '< 1.2.1' })
+    @set.required_by(Pod::Dependency.new('CocoaLumberjack', '< 1.2.1'), 'Spec')
   end
 
   it "returns the version required for the dependency" do
@@ -49,4 +49,9 @@ describe "Pod::Specification::Set" do
     `touch #{fixture('spec-repos/master/CocoaLumberjack/.DS_Store')}`
     lambda { @set.versions }.should.not.raise
   end
+
+  it "raises if a version is incompatible with the activated version" do
+    spec = Pod::Dependency.new('CocoaLumberjack', '1.2.1')
+    lambda { @set.required_by(spec, 'Spec') }.should.raise Pod::Informative
+  end
 end