Skip the role selection dialog when there is only one

Part of fate#324713

src/lib/installation/select_system_role.rb

@@ -64,6 +64,10 @@ def run
         direction = run_clients(clients, going_back: true)
         # ... and only run the main dialog (super) if we are *still* going back
         return direction unless direction == :back
+      elsif single_role?
+        # Apply the role and skip the dialog when there is only one (fate#324713)
+        clear_role
+        return select_role(roles.first.id)
       end
 
       super
@@ -92,26 +96,7 @@ def create_dialog
     end
 
     def next_handler
-      role_id = @selected_role_id
-
-      if role_id.nil? # no role selected (bsc#1078809)
-        # An Error popup
-        msg = _("Select one of the available roles to continue.")
-        Yast::Popup.Error(msg)
-        return
-      end
-
-      orig_role_id = self.class.original_role_id
-      if !orig_role_id.nil? && orig_role_id != role_id
-        # A Continue-Cancel popup
-        msg = _("Changing the system role may undo adjustments you may have done.")
-        return unless Yast::Popup.ContinueCancel(msg)
-      end
-      self.class.original_role_id = role_id
-
-      apply_role(SystemRole.find(role_id))
-
-      result = run_clients(additional_clients_for(role_id))
+      result = select_role(@selected_role_id)
       # We show the main role dialog; but the additional clients have
       # drawn over it, so draw it again and go back to input loop.
       # create_dialog do not create new dialog if it already exist like in this
@@ -139,6 +124,39 @@ def handle_event(id)
 
   private
 
+    # checks if there is only one role available
+    def single_role?
+      roles.size == 1
+    end
+
+    # Applies the role with given id and run its additional clients, if any
+    #
+    # @param role_id [Integer] The role to be applied
+    #
+    # @see run_clients
+    #
+    # @return [:next,:back,:abort] which direction the additional dialogs exited
+    def select_role(role_id)
+      if role_id.nil? # no role selected (bsc#1078809)
+        # An Error popup
+        msg = _("Select one of the available roles to continue.")
+        Yast::Popup.Error(msg)
+        return :back
+      end
+
+      orig_role_id = self.class.original_role_id
+      if !orig_role_id.nil? && orig_role_id != role_id
+        # A Continue-Cancel popup
+        msg = _("Changing the system role may undo adjustments you may have done.")
+        return :back unless Yast::Popup.ContinueCancel(msg)
+      end
+      self.class.original_role_id = role_id
+
+      apply_role(SystemRole.find(role_id))
+
+      run_clients(additional_clients_for(role_id))
+    end
+
     # gets array of clients to run for given role
     def additional_clients_for(role_id)
       role = SystemRole.find(role_id)

test/select_system_role_test.rb

@@ -25,7 +25,7 @@
       subject.class.original_role_id = nil
 
       allow(Yast::ProductFeatures).to receive(:ClearOverlay)
-      allow(Yast::ProductFeatures).to receive(:SetOverlay) # .with
+      allow(Yast::ProductFeatures).to receive(:SetOverlay)
       allow(Yast::Packages).to receive(:SelectSystemPatterns)
     end
 
@@ -41,6 +41,77 @@
       end
     end
 
+    context "when single role is defined" do
+      let(:additional_dialogs) { "" }
+      let(:control_file_roles) do
+        [
+          { "id" => "bar", "order" => "200",
+            "software" => { "desktop" => "knome" }, "additional_dialogs" => additional_dialogs }
+        ]
+      end
+
+      before do
+        allow(Yast::ProductControl).to receive(:system_roles)
+          .and_return(control_file_roles)
+        allow(Yast::WFM).to receive(:CallFunction).and_return(:next)
+      end
+
+      it "does not display dialog" do
+        expect(Yast::Wizard).to_not receive(:SetContents)
+        expect(Yast::UI).to_not receive(:UserInput)
+        expect(Yast::UI).to_not receive(:QueryWidget)
+
+        subject.run
+      end
+
+      context "and going forward" do
+        before do
+          allow(Yast::UI).to receive(:UserInput).and_return(:next)
+        end
+
+        it "sets ProductFeatures" do
+          expect(Yast::ProductFeatures).to receive(:ClearOverlay)
+          expect(Yast::ProductFeatures).to receive(:SetOverlay)
+
+          subject.run
+        end
+      end
+
+      context "and going back" do
+        before do
+          subject.class.original_role_id = "bar"
+          allow(Yast::GetInstArgs).to receive(:going_back).and_return(true)
+          allow(Yast::UI).to receive(:UserInput).and_return(:back)
+        end
+
+        it "leaves ProductFeatures" do
+          expect(Yast::ProductFeatures).to receive(:ClearOverlay)
+          expect(Yast::ProductFeatures).to_not receive(:SetOverlay)
+
+          subject.run
+        end
+      end
+
+      context "and it contains additional dialogs" do
+        let(:additional_dialogs) { "a,b" }
+
+        it "shows the first dialog when going forward" do
+          expect(Yast::WFM).to receive(:CallFunction).with("a", anything).and_return(:next)
+
+          subject.run
+        end
+
+        it "shows the last dialog when going back" do
+          subject.class.original_role_id = "bar"
+
+          allow(Yast::GetInstArgs).to receive(:going_back).and_return(true)
+          expect(Yast::WFM).to receive(:CallFunction).with("b", anything).and_return(:next)
+
+          subject.run
+        end
+      end
+    end
+
     context "when some roles are defined" do
       let(:control_file_roles) do
         [
@@ -61,7 +132,7 @@
           .and_return("foo", :next)
 
         expect(Yast::ProductFeatures).to receive(:ClearOverlay)
-        expect(Yast::ProductFeatures).to receive(:SetOverlay) # .with
+        expect(Yast::ProductFeatures).to receive(:SetOverlay)
 
         expect(subject.run).to eq(:next)
       end