Check for default on_error behavior setting

test/unit/plugins/kernel_v2/config/vm_trigger_test.rb

@@ -42,8 +42,14 @@ describe VagrantPlugins::Kernel_V2::VagrantConfigTrigger do
     end
 
     it "sets a command" do
+      subject.finalize!
       expect(subject.command).to eq(command)
     end
+
+    it "uses default error behavior" do
+      subject.finalize!
+      expect(subject.on_error).to eq(:halt)
+    end
   end
 
   describe "defining a new config that needs to match internal restraints" do