Merge pull request #408 from CocoaPods/informative

Add Pod::Podfile::Informative error which show lines in Podfile

lib/cocoapods/podfile.rb

 module Pod
   class Podfile
+    class Informative < ::Pod::Informative
+      def podfile_line
+        @podfile_line ||= self.backtrace.find {|t| t =~ /Podfile/}
+      end
+
+      def message
+        if podfile_line
+          super + " (#{podfile_line})\n".red
+        else
+          super
+        end
+      end
+    end
+
     class UserProject
       include Config::Mixin
 
@@ -200,7 +214,7 @@ module Pod
         when :osx
           target = '10.6'
         else
-          raise Informative, "Unsupported platform: platform must be one of [:ios, :osx]"
+          raise ::Pod::Podfile::Informative, "Unsupported platform: platform must be one of [:ios, :osx]"
         end
       end
       @target_definition.platform = Platform.new(name, target)

spec/unit/podfile_spec.rb

@@ -19,7 +19,14 @@ describe "Pod::Podfile" do
   it "raise error if unsupported platform is supplied" do
     lambda {
       Pod::Podfile.new { platform :iOS }
-    }.should.raise(StandardError, "Unsupported platform")
+    }.should.raise Pod::Podfile::Informative
+
+    begin
+      Pod::Podfile.new { platform :iOS }
+    rescue Pod::Podfile::Informative => e
+      e.stubs(:podfile_line).returns("./podfile_spec.rb:1")
+      e.message.should.be =~ /podfile_spec\.rb:1/
+    end
   end
 
   it "adds dependencies" do