Spec fixed

spec/models/budget/heading_spec.rb

@@ -26,17 +26,22 @@ describe Budget::Heading do
   end
 
   describe "Save population" do
-    it "Allows nil for population" do
-      expect(create(:budget_heading, group: group, name: 'Population is nil')).to be_valid
+    it "Allows population == nil" do
+      expect(create(:budget_heading, group: group, name: 'Population is nil', population: nil)).to be_valid
     end
 
-    it "Doesn't allow 0 for population" do
-      expect(create(:budget_heading, group: group, name: 'Population is 0', population: 0)).not_to be_valid
-    end
-
-    it "Allows value > 0 for population" do
-      expect(create(:budget_heading, group: group, name: 'Population is 10', population: 10)).to be_valid
-    end    
+    it "Doesn't allow population <= 0" do
+      heading = create(:budget_heading, group: group, name: 'Population is > 0')
+      
+      heading.population = 0
+      expect(heading).not_to be_valid
+      
+      heading.population = -10
+      expect(heading).not_to be_valid
+      
+      heading.population = 10
+      expect(heading).to be_valid
+    end 
   end
 
 end