[Installer] Adds support for a pre-installer hook

CHANGELOG.md

@@ -13,6 +13,13 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
   [Samuel Giddins](https://github.com/segiddins)
   [cocoapods-try#31](https://github.com/CocoaPods/cocoapods-try/issues/31)
 
+* Supports running pre-install hooks in plugins. This happens before the resolver
+  does its work, and offers easy access to the sandbox, podfile and lockfile via a 
+  PreInstallHooksContext object. This also renames the post-install hooks from HooksContext
+  to PostInstallHooksContext.
+
+  [Orta Therox](https://github.com/orta)
+  [cocoapods#3540](https://github.com/CocoaPods/cocoapods/issues/3409)
 
 ## 0.37.1
 

lib/cocoapods/installer.rb

@@ -31,7 +31,8 @@ module Pod
     autoload :AggregateTargetInstaller, 'cocoapods/installer/target_installer/aggregate_target_installer'
     autoload :Analyzer,                 'cocoapods/installer/analyzer'
     autoload :FileReferencesInstaller,  'cocoapods/installer/file_references_installer'
-    autoload :HooksContext,             'cocoapods/installer/hooks_context'
+    autoload :PostInstallHooksContext,  'cocoapods/installer/post_install_hooks_context'
+    autoload :PreInstallHooksContext,   'cocoapods/installer/pre_install_hooks_context'
     autoload :Migrator,                 'cocoapods/installer/migrator'
     autoload :PodSourceInstaller,       'cocoapods/installer/pod_source_installer'
     autoload :PodSourcePreparer,        'cocoapods/installer/pod_source_preparer'
@@ -104,6 +105,7 @@ module Pod
         sandbox.prepare
         ensure_plugins_are_installed!
         Migrator.migrate(sandbox)
+        run_plugins_pre_install_hooks
       end
     end
 
@@ -120,7 +122,7 @@ module Pod
       UI.section 'Downloading dependencies' do
         create_file_accessors
         install_pod_sources
-        run_pre_install_hooks
+        run_podfile_pre_install_hooks
         clean_pod_sources
         lock_pod_sources
       end
@@ -397,7 +399,16 @@ module Pod
         end
       end
     end
-
+    
+    # Runs the registered callbacks for the plugins pre install hooks.
+    #
+    # @return [void]
+    #
+    def run_plugins_pre_install_hooks
+      context = PreInstallHooksContext.generate(sandbox, podfile, lockfile)
+      HooksManager.run(:pre_install, context, podfile.plugins)
+    end
+    
     # Performs any post-installation actions
     #
     # @return [void]
@@ -410,7 +421,7 @@ module Pod
     # Runs the registered callbacks for the plugins post install hooks.
     #
     def run_plugins_post_install_hooks
-      context = HooksContext.generate(sandbox, aggregate_targets)
+      context = PostInstallHooksContext.generate(sandbox, aggregate_targets)
       HooksManager.run(:post_install, context, podfile.plugins)
     end
 
@@ -652,7 +663,7 @@ module Pod
     #
     # @return [void]
     #
-    def run_pre_install_hooks
+    def run_podfile_pre_install_hooks
       UI.message '- Running pre install hooks' do
         executed = run_podfile_pre_install_hook
         UI.message '- Podfile' if executed

lib/cocoapods/installer/hooks_context.rb → lib/cocoapods/installer/post_install_hooks_context.rb

@@ -3,7 +3,7 @@ module Pod
     # Context object designed to be used with the HooksManager which describes
     # the context of the installer.
     #
-    class HooksContext
+    class PostInstallHooksContext
       # @return [String] The path to the sandbox root (`Pods` directory).
       #
       attr_accessor :sandbox_root
@@ -13,7 +13,7 @@ module Pod
       #
       attr_accessor :umbrella_targets
 
-      # @return [HooksContext] Convenience class method to generate the
+      # @return [PostInstallHooksContext] Convenience class method to generate the
       #         static context.
       #
       def self.generate(sandbox, aggregate_targets)

lib/cocoapods/installer/pre_install_hooks_context.rb

+module Pod
+  class Installer
+    # Context object designed to be used with the HooksManager which describes
+    # the context of the installer before analysis has been completed.
+    #
+    class PreInstallHooksContext
+      # @return [String] The path to the sandbox root (`Pods` directory).
+      #
+      attr_accessor :sandbox_root
+
+      # @return [Podfile] The Podfile for the project.
+      #
+      attr_accessor :podfile
+      
+      # @return [Sandbox] The Sandbox for the project.
+      #
+      attr_accessor :sandbox
+      
+      # @return [Lockfile] The Lockfile for the project.
+      #
+      attr_accessor :lockfile
+      
+      # @return [PreInstallHooksContext] Convenience class method to generate the
+      #         static context.
+      #
+      def self.generate(sandbox, podfile, lockfile)
+        result = new
+        result.podfile = podfile
+        result.sandbox = sandbox
+        result.lockfile = lockfile
+        result
+      end
+    end
+  end
+end

spec/unit/installer/post_install_hooks_context_spec.rb

+
+require File.expand_path('../../../spec_helper', __FILE__)
+
+module Pod
+  describe Installer::PreInstallHooksContext do
+    it 'offers a convenience method to be generated' do
+      sandbox, podfile, lockfile = stub, stub, stub
+
+      result = Installer::PreInstallHooksContext.generate(sandbox, podfile, lockfile)
+      result.class.should == Installer::PreInstallHooksContext
+      result.sandbox.should == sandbox
+      result.podfile.should == podfile
+      result.lockfile.should == lockfile
+    end
+  end
+end

spec/unit/installer/hooks_context_spec.rb → spec/unit/installer/pre_install_hooks_context_spec.rb

@@ -2,7 +2,7 @@
 require File.expand_path('../../../spec_helper', __FILE__)
 
 module Pod
-  describe Installer::HooksContext do
+  describe Installer::PostInstallHooksContext do
     it 'offers a convenience method to be generated' do
       sandbox = stub(:root => '/path')
 
@@ -15,8 +15,8 @@ module Pod
       umbrella.stubs(:platform).returns(Platform.new(:ios, '8.0'))
       umbrella.pod_targets = [pod_target]
 
-      result = Installer::HooksContext.generate(sandbox, [umbrella])
-      result.class.should == Installer::HooksContext
+      result = Installer::PostInstallHooksContext.generate(sandbox, [umbrella])
+      result.class.should == Installer::PostInstallHooksContext
       result.sandbox_root.should == '/path'
       result.umbrella_targets.count.should == 1
       umbrella_target = result.umbrella_targets.first

spec/unit/installer_spec.rb

@@ -63,7 +63,7 @@ module Pod
         @installer.unstub(:download_dependencies)
         @installer.stubs(:create_file_accessors)
         @installer.stubs(:install_pod_sources)
-        def @installer.run_pre_install_hooks
+        def @installer.run_podfile_pre_install_hooks
           @hook_called = true
         end
         def @installer.clean_pod_sources
@@ -74,7 +74,7 @@ module Pod
 
       it 'in runs the post-install hooks before serializing the Pods project' do
         @installer.stubs(:prepare_pods_project)
-        @installer.stubs(:run_pre_install_hooks)
+        @installer.stubs(:run_podfile_pre_install_hooks)
         @installer.stubs(:install_file_references)
         @installer.stubs(:install_libraries)
         @installer.stubs(:set_target_dependencies)
@@ -654,16 +654,23 @@ module Pod
         @installer.stubs(:installed_specs).returns(@specs)
       end
 
+      it 'runs plugins pre install hook' do
+        context = stub
+        Installer::PreInstallHooksContext.expects(:generate).returns(context)
+        HooksManager.expects(:run).with(:pre_install, context, {})
+        @installer.send(:run_plugins_pre_install_hooks)
+      end
+
       it 'runs plugins post install hook' do
         context = stub
-        Installer::HooksContext.expects(:generate).returns(context)
+        Installer::PostInstallHooksContext.expects(:generate).returns(context)
         HooksManager.expects(:run).with(:post_install, context, {})
         @installer.send(:run_plugins_post_install_hooks)
       end
 
-      it 'only runs the podfile-specified post-install hooks' do
+      it 'only runs the podfile-specified hooks' do
         context = stub
-        Installer::HooksContext.expects(:generate).returns(context)
+        Installer::PostInstallHooksContext.expects(:generate).returns(context)
         plugins_hash = { 'cocoapods-keys' => { 'keyring' => 'Eidolon' } }
         @installer.podfile.stubs(:plugins).returns(plugins_hash)
         HooksManager.expects(:run).with(:post_install, context, plugins_hash)
@@ -691,7 +698,7 @@ module Pod
 
     #-------------------------------------------------------------------------#
 
-    describe 'Hooks' do
+    describe 'Podfile Hooks' do
       before do
         @installer.send(:analyze)
         @specs = @installer.pod_targets.map(&:specs).flatten
@@ -705,7 +712,7 @@ module Pod
 
         @installer.expects(:installer_rep).returns(installer_rep)
         @installer.podfile.expects(:pre_install!).with(installer_rep)
-        @installer.send(:run_pre_install_hooks)
+        @installer.send(:run_podfile_pre_install_hooks)
       end
 
       it 'run_podfile_post_install_hooks' do
@@ -725,7 +732,7 @@ module Pod
         @installer.stubs(:pod_targets).returns([pod_target_ios, pod_target_osx])
         @installer.stubs(:installer_rep).returns(stub)
         @installer.podfile.expects(:pre_install!)
-        @installer.send(:run_pre_install_hooks)
+        @installer.send(:run_podfile_pre_install_hooks)
         @installer.send(:run_podfile_post_install_hooks)
       end