Add gemspec support in group clause

Fixes #76

Author: Prem Sichanugrist

lib/appraisal/group.rb

@@ -6,6 +6,7 @@ class Group
     def initialize(group_names)
       @dependencies = DependencyList.new
       @group_names = group_names
+      @gemspec = nil
     end
 
     def run(&block)
@@ -16,9 +17,26 @@ def gem(name, *requirements)
       @dependencies.add(name, requirements)
     end
 
+    def gemspec(options = {})
+      @gemspec = Gemspec.new(options)
+    end
+
     def to_s
-      "group #{Utils.format_arguments(@group_names)} do\n" +
-        @dependencies.to_s.strip.gsub(/^/, '  ') + "\nend"
+      <<-OUTPUT.strip
+group #{Utils.format_arguments(@group_names)} do
+  #{dependencies_list}
+end
+      OUTPUT
+    end
+
+    private
+
+    def dependencies_list
+      [@dependencies.to_s, @gemspec.to_s].
+        reject(&:empty?).
+        join("\n\n").
+        gsub(/^/, "  ").
+        strip
     end
   end
 end

spec/acceptance/gemfile_dsl_compatibility_spec.rb

@@ -136,4 +136,37 @@
     expect(content_of "gemfiles/1.1.0.gemfile").to include('gem "bacon", "1.1.0"')
     expect(content_of "gemfiles/1.2.0.gemfile").to include('gem "bacon", "1.2.0"')
   end
+
+  it "supports gemspec in the group block" do
+    build_gem "bacon", "1.0.0"
+    build_gemspec
+
+    build_gemfile <<-Gemfile
+      gem "appraisal", path: #{PROJECT_ROOT.inspect}
+
+      group :plugin do
+        gemspec
+      end
+    Gemfile
+
+    build_appraisal_file <<-Appraisals
+      appraise "1.0.0" do
+        gem "bacon", "1.0.0"
+      end
+    Appraisals
+
+    run "bundle install --local"
+    run "appraisal generate"
+
+    expect(content_of "gemfiles/1.0.0.gemfile").to eq <<-gemfile.strip_heredoc
+      # This file was generated by Appraisal
+
+      gem "appraisal", :path => #{PROJECT_ROOT.inspect}
+      gem "bacon", "1.0.0"
+
+      group :plugin do
+        gemspec :path => "../"
+      end
+    gemfile
+  end
 end