don't disable the display if previously enabled outside with_display

Author: ianfixes

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - `DisplayManager` class for managing Xvfb instance if needed
 
 ### Changed
+- `DisplayManger.with_display` doesn't `disable` if the display was enabled prior to starting the block
 
 ### Deprecated
 

lib/arduino_ci/display_manager.rb

@@ -52,11 +52,12 @@ def disable
 
     # Enable a virtual display for the duration of the given block
     def with_display
-      enable
+      was_enabled = @enabled
+      enable unless was_enabled
       begin
         yield environment
       ensure
-        disable
+        disable unless was_enabled
       end
     end
 

spec/display_manager_spec.rb

@@ -8,8 +8,10 @@
   end
 
   context "with_display" do
-    it "Properly enables and disables" do
-      manager = ArduinoCI::DisplayManager::instance
+    manager = ArduinoCI::DisplayManager::instance
+    manager.disable
+
+    it "Properly enables and disables when not previously enabled" do
       expect(manager.enabled).to be false
       manager.with_display do |environment|
         expect(manager.enabled).to be true
@@ -19,5 +21,17 @@
       end
       expect(manager.enabled).to be false
     end
+
+    it "Properly enables and disables when previously enabled" do
+      manager.enable
+      expect(manager.enabled).to be true
+      manager.with_display do |environment|
+        expect(manager.enabled).to be true
+        expect(environment.class).to eq(Hash)
+        also_manager = ArduinoCI::DisplayManager::instance
+        expect(also_manager.enabled).to be true
+      end
+      expect(manager.enabled).to be true
+    end
   end
 end