[Config] Sort by setting name when serliazing to a string.

Part of CocoaPods/CocoaPods#591.

Rakefile

@@ -209,6 +209,11 @@ task :dump_xcodeproj => 'ext:cleanbuild' do
   puts result.to_yaml
 end
 
+desc 'Install dependencies'
+task :bootstrap do
+  sh 'bundle install'
+end
+
 desc "Run all specs"
 task :spec => 'spec:all'
 

lib/xcodeproj/config.rb

@@ -47,16 +47,17 @@ def initialize(xcconfig_hash_or_file = {})
 
     # @!group Serialization
 
-    # Serializes the internal data in the xcconfig format.
+    # Sorts the internal data by setting name and serializes it in the xcconfig
+    # format.
     #
     # @example
     #
     #   config = Config.new('PODS_ROOT' => '"$(SRCROOT)/Pods"', 'OTHER_LDFLAGS' => '-lxml2')
-    #   config.to_s # => "PODS_ROOT = \"$(SRCROOT)/Pods\"\nOTHER_LDFLAGS = -lxml2"
+    #   config.to_s # => "OTHER_LDFLAGS = -lxml2\nPODS_ROOT = \"$(SRCROOT)/Pods\""
     #
     # @return [String]  The serialized internal data.
     def to_s
-      to_hash.map { |key, value| "#{key} = #{value}" }.join("\n")
+      to_hash.sort_by(&:first).map { |k, v| "#{k} = #{v}" }.join("\n")
     end
 
     # @return [void] Writes the serialized representation of the internal data

spec/config_spec.rb

@@ -50,6 +50,11 @@
     @config.to_s.should.be.equal "OTHER_LDFLAGS = -framework Foundation"
   end
 
+  it "sorts the internal data by setting name when serializing with #to_s" do
+    config = Xcodeproj::Config.new('Y' => '2', 'Z' => '3', 'X' => '1')
+    config.to_s.should == "X = 1\nY = 2\nZ = 3"
+  end
+
   it "can be serialized with #to_hash" do
     @config.to_hash.should.be.equal @hash
   end