More tests..

Clocker/ClockerUnitTests/ThemerTests.swift

@@ -5,6 +5,20 @@ import XCTest
 @testable import Clocker
 
 class ThemerTests: XCTestCase {
+    
+    @available(macOS 10.14, *)
+    func testSettingTheme() {
+        let subject = Themer(index: 0)
+        XCTAssertEqual(NSAppearance(named: .aqua), NSAppearance(named: .aqua))
+        
+        // Set the same theme; this should return early
+        subject.set(theme: 0)
+        
+        // Set the theme to dark theme
+        subject.set(theme: 1)
+        let expectedApperance = NSAppearance(named: .darkAqua)
+        XCTAssertEqual(expectedApperance, NSApp.appearance)
+    }
 
     func testLightTheme() throws {
         let subject = Themer(index: 0) // 0 is for light theme

Clocker/Overall App/Themer.swift

@@ -168,20 +168,11 @@ extension Themer {
             return symbolImageForShutdown
         }
 
-        if #available(macOS 10.14, *) {
-            switch themeIndex {
-            case .light:
-                return NSImage(named: NSImage.Name("PowerIcon"))!
-            case .dark, .solarizedDark:
-                return NSImage(named: NSImage.Name("PowerIcon-White"))!
-            case .system:
-                return NSImage(named: NSImage.Name("Power"))!
-            case .solarizedLight:
-                return NSImage(named: NSImage.Name("PowerIcon"))!
-            }
-        }
-
-        return themeIndex == .light ? NSImage(named: NSImage.Name("PowerIcon"))! : NSImage(named: NSImage.Name("PowerIcon-White"))!
+        return fallbackImageProvider(NSImage(named: NSImage.Name("PowerIcon"))!,
+                                     NSImage(named: NSImage.Name("PowerIcon-White"))!,
+                                     NSImage(named: NSImage.Name("Power"))!,
+                                     NSImage(named: NSImage.Name("PowerIcon"))!,
+                                     NSImage(named: NSImage.Name("PowerIcon-White"))!)
     }
 
     func preferenceImage() -> NSImage {
@@ -257,11 +248,11 @@ extension Themer {
             case .system:
                 return NSImage(named: NSImage.Name("Dynamic Menubar"))!
             default:
-                return UserDefaults.standard.string(forKey: "AppleInterfaceStyle") == "Dark" ? NSImage(named: NSImage.Name("Dark Menubar"))! : NSImage(named: NSImage.Name("Light Menubar"))!
+                return retrieveCurrentSystem() == .dark ? NSImage(named: NSImage.Name("Dark Menubar"))! : NSImage(named: NSImage.Name("Light Menubar"))!
             }
         }
 
-        return UserDefaults.standard.string(forKey: "AppleInterfaceStyle") == "Dark" ? NSImage(named: NSImage.Name("Dark Menubar"))! : NSImage(named: NSImage.Name("Light Menubar"))!
+        return retrieveCurrentSystem() == .dark ? NSImage(named: NSImage.Name("Dark Menubar"))! : NSImage(named: NSImage.Name("Light Menubar"))!
     }
 
     func extraOptionsHighlightedImage() -> NSImage {