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spec/models/section_spec.rb

@@ -5,6 +5,10 @@ describe :section do
     @section = build :section, path: [[10, 30], [20,30], [20,40], [10, 40]]
   end
 
+  it "creates without problem" do
+    expect{ @section.save }.not_to raise_error
+  end
+
   describe :path do
     describe :width do
       it "should have 20 width when initialized" do