[Installer] Add support for source provider plugin hook

CHANGELOG.md

@@ -136,6 +136,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
   is now a default plugin.  
   [Samuel Giddins](https://github.com/segiddins)
 
+* Added a `:source_provider` hook to allow plugins to provide their own sources
+  [Eric Amorde](https://github.com/amorde)
+  [#3792](https://github.com/CocoaPods/CocoaPods/pull/3792)
+
 ##### Bug Fixes
 
 * Ensure that the `prepare_command` is run even when skipping the download

lib/cocoapods/installer.rb

@@ -29,18 +29,19 @@ module Pod
   # source control.
   #
   class Installer
-    autoload :AggregateTargetInstaller, 'cocoapods/installer/target_installer/aggregate_target_installer'
-    autoload :Analyzer,                 'cocoapods/installer/analyzer'
-    autoload :FileReferencesInstaller,  'cocoapods/installer/file_references_installer'
-    autoload :PostInstallHooksContext,  'cocoapods/installer/post_install_hooks_context'
-    autoload :PreInstallHooksContext,   'cocoapods/installer/pre_install_hooks_context'
-    autoload :Migrator,                 'cocoapods/installer/migrator'
-    autoload :PodfileValidator,         'cocoapods/installer/podfile_validator'
-    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'
+    autoload :AggregateTargetInstaller,   'cocoapods/installer/target_installer/aggregate_target_installer'
+    autoload :Analyzer,                   'cocoapods/installer/analyzer'
+    autoload :FileReferencesInstaller,    'cocoapods/installer/file_references_installer'
+    autoload :PostInstallHooksContext,    'cocoapods/installer/post_install_hooks_context'
+    autoload :PreInstallHooksContext,     'cocoapods/installer/pre_install_hooks_context'
+    autoload :SourceProviderHooksContext, 'cocoapods/installer/source_provider_hooks_context'
+    autoload :Migrator,                   'cocoapods/installer/migrator'
+    autoload :PodfileValidator,           'cocoapods/installer/podfile_validator'
+    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'
 
     include Config::Mixin
 
@@ -125,6 +126,9 @@ module Pod
     def resolve_dependencies
       analyzer = create_analyzer
 
+      plugin_sources = run_source_provider_hooks
+      analyzer.sources.push(*plugin_sources)
+
       UI.section 'Updating local specs repositories' do
         analyzer.update_repositories
       end unless config.skip_repo_update?
@@ -453,6 +457,16 @@ module Pod
       HooksManager.run(:post_install, context, plugins)
     end
 
+    # Runs the registered callbacks for the source provider plugin hooks.
+    #
+    # @return [void]
+    #
+    def run_source_provider_hooks
+      context = SourceProviderHooksContext.generate
+      HooksManager.run(:source_provider, context, plugins)
+      context.sources
+    end
+
     # Ensures that all plugins specified in the {#podfile} are loaded.
     #
     # @return [void]

lib/cocoapods/installer/source_provider_hooks_context.rb

+module Pod
+  class Installer
+    # Context object designed to be used with the HooksManager which describes
+    # the context of the installer before spec sources have been created
+    #
+    class SourceProviderHooksContext
+      # @return [Array<Source>] The source objects to send to the installer
+      #
+      attr_reader :sources
+
+      # @return [SourceProviderHooksContext] Convenience class method to generate the
+      #         static context.
+      #
+      def self.generate
+        result = new
+        result
+      end
+
+      def initialize
+        @sources = []
+      end
+
+      # @param [Source] Source object to be added to the installer
+      #
+      def add_source(source)
+        unless source.nil?
+          @sources << source
+        end
+      end
+    end
+  end
+end

spec/unit/installer/source_provider_hooks_context_spec.rb

+
+require File.expand_path('../../../spec_helper', __FILE__)
+
+module Pod
+  describe Installer::SourceProviderHooksContext do
+    it 'offers a convenience method to be generated' do
+      result = Installer::SourceProviderHooksContext.generate
+      result.class.should == Installer::SourceProviderHooksContext
+      result.sources.should == []
+    end
+  end
+end

spec/unit/installer_spec.rb

@@ -93,6 +93,51 @@ module Pod
         @installer.install!
       end
 
+      it 'runs source provider hooks before analyzing' do
+        config.skip_repo_update = true
+        @installer.unstub(:resolve_dependencies)
+        @installer.stubs(:validate_build_configurations)
+        @installer.stubs(:prepare_for_legacy_compatibility)
+        @installer.stubs(:clean_sandbox)
+        def @installer.run_source_provider_hooks
+          @hook_called = true
+        end
+        def @installer.analyze(*)
+          @hook_called.should.be.true
+        end
+        @installer.install!
+      end
+
+      it 'includes sources from source provider plugins' do
+        plugin_name = 'test-plugin'
+        Pod::HooksManager.register(plugin_name, :source_provider) do |context, options|
+          source_url = options['sources'].first
+          return unless source_url
+          source = Pod::Source.new(source_url)
+          context.add_source(source)
+        end
+
+        test_source_name = 'https://github.com/artsy/Specs.git'
+        plugins_hash = Installer::DEFAULT_PLUGINS.merge(plugin_name => { 'sources' => [test_source_name] })
+        @installer.podfile.stubs(:plugins).returns(plugins_hash)
+        @installer.unstub(:resolve_dependencies)
+        @installer.stubs(:validate_build_configurations)
+        @installer.stubs(:prepare_for_legacy_compatibility)
+        @installer.stubs(:clean_sandbox)
+        @installer.stubs(:ensure_plugins_are_installed!)
+        @installer.stubs(:analyze)
+        config.skip_repo_update = true
+
+        analyzer = Installer::Analyzer.new(config.sandbox, @installer.podfile, @installer.lockfile)
+        analyzer.stubs(:analyze)
+        @installer.stubs(:create_analyzer).returns(analyzer)
+        @installer.install!
+
+        source = Pod::Source.new(test_source_name)
+        names = analyzer.sources.map(&:name)
+        names.should.include(source.name)
+      end
+
       it 'integrates the user targets if the corresponding config is set' do
         config.integrate_targets = true
         @installer.expects(:integrate_user_project)
@@ -726,6 +771,14 @@ module Pod
         @installer.send(:run_plugins_post_install_hooks)
       end
 
+      it 'runs plugins source provider hook' do
+        context = stub
+        context.stubs(:sources).returns([])
+        Installer::SourceProviderHooksContext.expects(:generate).returns(context)
+        HooksManager.expects(:run).with(:source_provider, context, Installer::DEFAULT_PLUGINS)
+        @installer.send(:run_source_provider_hooks)
+      end
+
       it 'only runs the podfile-specified hooks' do
         context = stub
         Installer::PostInstallHooksContext.expects(:generate).returns(context)