merge jasmine.yml keys the same way as the gem

lib/jasmine/headless/runner.rb

@@ -45,9 +45,13 @@ module Jasmine
       end
 
       def jasmine_config
-        raise JasmineConfigNotFound.new("Jasmine config not found. I tried #{@options[:jasmine_config]}.") if !File.file?(@options[:jasmine_config])
+        return @jasmine_config if @jasmine_config
 
-        @jasmine_config ||= JASMINE_DEFAULTS.dup.merge(YAML.load_file(@options[:jasmine_config]))
+        @jasmine_config = JASMINE_DEFAULTS.dup
+        jasmine_config_data.each do |key, value|
+          @jasmine_config[key] = value if value
+        end
+        @jasmine_config
       end
 
       def jasmine_command(*targets)
@@ -88,6 +92,13 @@ module Jasmine
           end
         end
       end
+
+      private
+      def jasmine_config_data
+        raise JasmineConfigNotFound.new("Jasmine config not found. I tried #{@options[:jasmine_config]}.") if !File.file?(@options[:jasmine_config])
+
+        YAML.load_file(@options[:jasmine_config])
+      end
     end
   end
 end

spec/lib/jasmine/headless/runner_spec.rb

@@ -155,4 +155,16 @@ describe Jasmine::Headless::Runner do
       end
     end
   end
+
+  describe '#jasmine_config' do
+    let(:opts) { {} }
+
+    before do
+      runner.stubs(:jasmine_config_data).returns('spec_files' => nil)
+    end
+
+    it 'should not merge in things with nil values' do
+      runner.jasmine_config['spec_files'].should == described_class::JASMINE_DEFAULTS['spec_files']
+    end
+  end
 end