[Genenrator::PrefixHeader] Added.

lib/cocoapods/generator/prefix_header.rb

+module Pod
+  module Generator
+
+    # Generates a prefix header file for a Pods library. The prefix header is
+    # generated according to the platform of the target and the pods.
+    #
+    # According to the platform the prefix header imports `UIKit/UIKit.h` or
+    # `Cocoa/Cocoa.h`.
+    #
+    class PrefixHeader
+
+      # @return [Platform] the platform for which the prefix header will be
+      # generated.
+      #
+      attr_reader :platform
+
+      # @return [Array<LocalPod>] the LocalPod for the target for which the
+      # prefix header needs to be generated.
+      #
+      attr_reader :pods
+
+      # @param  [Platform] platform @see platform
+      #
+      # @param  [Array<LocalPod>]   @see pods
+      #
+      def initialize(platform, pods)
+        @platform = platform
+        @pods = pods
+      end
+
+      #--------------------------------------#
+
+      # Generates the contents of the prefix header according to the platform
+      # and the pods.
+      #
+      # @note   If the platform is iOS an import call to `UIKit/UIKit.h` is
+      #         added to the top of the prefix header. For OS X `Cocoa/Cocoa.h`
+      #         is imported.
+      #
+      # @return [String]
+      #
+      # TODO:   Subspecs can specify prefix header information too.
+      #
+      def generate
+        result =  "#ifdef __OBJC__\n"
+        result << "#import #{platform == :ios ? '<UIKit/UIKit.h>' : '<Cocoa/Cocoa.h>'}\n"
+        result << "#endif\n"
+
+        pods.each do |pod|
+          result << "\n"
+          if prefix_header_contents = pod.top_specification.prefix_header_contents
+            result << prefix_header_contents
+            result << "\n"
+          elsif prefix_header = pod.prefix_header_file
+            result << prefix_header.read
+          end
+        end
+        result
+      end
+
+      # Generates and saves the prefix header to the given path.
+      #
+      # @param  [Pathname] path
+      #         the path where the prefix header should be stored.
+      #
+      # @return [void]
+      #
+      def save_as(path)
+        path.open('w') { |header| header.write(generate) }
+      end
+    end
+  end
+end

spec/unit/generator/prefix_header_spec.rb

+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe PrefixHeader = Pod::Generator::PrefixHeader do
+
+  before do
+    platform      = Pod::Platform.ios
+    specification = fixture_spec('banana-lib/BananaLib.podspec')
+    @pod          = Pod::LocalPod.new(specification, nil, platform)
+    pods          = [ @pod ]
+    @gen          = PrefixHeader.new(platform, pods)
+
+    @pod.stubs(:root).returns(Pathname.new(fixture('banana-lib')))
+  end
+
+  it "includes the contents of the specification's prefix header" do
+    spec = @pod.top_specification
+    spec.prefix_header_contents = '#import "BlocksKit.h"'
+    @gen.generate.should == <<-EOS.strip_heredoc
+      #ifdef __OBJC__
+      #import <UIKit/UIKit.h>
+      #endif
+
+      #import "BlocksKit.h"
+    EOS
+  end
+
+  it "includes the contents of the specification's prefix header file" do
+    @gen.generate.should == <<-EOS.strip_heredoc
+      #ifdef __OBJC__
+      #import <UIKit/UIKit.h>
+      #endif
+
+      #import <BananaTree/BananaTree.h>
+    EOS
+  end
+
+  it "prefers the inline specification of the prefix header contents" do
+    spec = @pod.top_specification
+    spec.prefix_header_contents = '#import "BlocksKit.h"'
+    @pod.prefix_header_file.should.be.not.nil
+    @gen.generate.should == <<-EOS.strip_heredoc
+      #ifdef __OBJC__
+      #import <UIKit/UIKit.h>
+      #endif
+
+      #import "BlocksKit.h"
+    EOS
+  end
+
+  it "imports UIKit in iOS platforms" do
+    @gen.stubs(:platform).returns(Pod::Platform.ios)
+    @gen.generate.should.include?('#import <UIKit/UIKit.h>')
+  end
+
+  it "imports Cocoa for OS X platforms" do
+    @gen.stubs(:platform).returns(Pod::Platform.osx)
+    @gen.generate.should.include?('#import <Cocoa/Cocoa.h>')
+  end
+
+  extend SpecHelper::TemporaryDirectory
+
+  it "writes the prefix header file to the disk" do
+    path = temporary_directory + 'Test.pch'
+    @gen.save_as(path)
+    path.read.should == <<-EOS.strip_heredoc
+      #ifdef __OBJC__
+      #import <UIKit/UIKit.h>
+      #endif
+
+      #import <BananaTree/BananaTree.h>
+    EOS
+  end
+end