fixed testcase

test/cfa/systemd_boot_test.rb

@@ -60,7 +60,26 @@
   describe "#menue_timeout=" do
     it "sets the menue_timeout value" do
       expect { subject.menue_timeout = "15" }
-        .to change { subject.menue_timeout }.from("10").to("16")
+        .to change { subject.menue_timeout }.from("10").to("15")
+    end
+  end
+
+  describe "#save" do
+    let(:timeout) { "20" }
+
+    before do
+      allow(Yast::SCR).to receive(:Write)
+      allow(file_handler).to receive(:read).with(file_path)
+        .and_return("# Some comment\ntimeout 5")
+      subject.load
+      subject.menue_timeout = timeout
+    end
+
+    it "writes changes to configuration file" do
+      expect(file_handler).to receive(:write)
+        .with(file_path, /.*timeout #{timeout}.*/)
+
+      subject.save
     end
   end