Fix theme picker text when unspecified theme

web/packages/design/src/ThemeProvider/index.tsx

@@ -39,6 +39,24 @@ function themePreferenceToTheme(themePreference: Theme) {
   return themePreference === Theme.LIGHT ? lightTheme : darkTheme;
 }
 
+// because unspecified can exist but only used as a fallback and not an option,
+// we need to get the current/next themes with getPrefersDark in mind.
+// TODO (avatus) when we add user settings page, we can add a Theme.SYSTEM option
+// and remove the checks for unspecified
+export function getCurrentTheme(currentTheme: Theme): Theme {
+  if (currentTheme === Theme.UNSPECIFIED) {
+    return getPrefersDark() ? Theme.DARK : Theme.LIGHT;
+  }
+
+  return currentTheme;
+}
+
+export function getNextTheme(currentTheme: Theme): Theme {
+  return getCurrentTheme(currentTheme) === Theme.LIGHT
+    ? Theme.DARK
+    : Theme.LIGHT;
+}
+
 export function getPrefersDark(): boolean {
   return (
     window.matchMedia &&

web/packages/teleport/src/components/UserMenuNav/UserMenuNav.tsx

@@ -22,6 +22,7 @@ import styled, { useTheme } from 'styled-components';
 import { Moon, Sun, ChevronDown, Logout as LogoutIcon } from 'design/Icon';
 import { Text } from 'design';
 import { useRefClickOutside } from 'shared/hooks/useRefClickOutside';
+import { getCurrentTheme, getNextTheme } from 'design/ThemeProvider';
 
 import { Theme } from 'gen-proto-ts/teleport/userpreferences/v1/theme_pb';
 
@@ -124,11 +125,10 @@ export function UserMenuNav({ username, iconSize }: UserMenuNavProps) {
   const ctx = useTeleport();
   const clusterId = ctx.storeUser.getClusterId();
   const features = useFeatures();
+  const currentTheme = getCurrentTheme(preferences.theme);
+  const nextTheme = getNextTheme(preferences.theme);
 
   const onThemeChange = () => {
-    const nextTheme =
-      preferences.theme === Theme.LIGHT ? Theme.DARK : Theme.LIGHT;
-
     updatePreferences({ theme: nextTheme });
     setOpen(false);
   };
@@ -182,10 +182,9 @@ export function UserMenuNav({ username, iconSize }: UserMenuNavProps) {
           <DropdownItem open={open} $transitionDelay={transitionDelay}>
             <DropdownItemButton onClick={onThemeChange}>
               <DropdownItemIcon>
-                {preferences.theme === Theme.DARK ? <Sun /> : <Moon />}
+                {currentTheme === Theme.DARK ? <Sun /> : <Moon />}
               </DropdownItemIcon>
-              Switch to {preferences.theme === Theme.DARK ? 'Light' : 'Dark'}{' '}
-              Theme
+              Switch to {currentTheme === Theme.DARK ? 'Light' : 'Dark'} Theme
             </DropdownItemButton>
           </DropdownItem>
         )}

web/packages/teleport/src/services/userPreferences/userPreferences.test.ts

@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+import { getCurrentTheme, getNextTheme } from 'design/ThemeProvider';
 import { Theme } from 'gen-proto-ts/teleport/userpreferences/v1/theme_pb';
 import { UserPreferences } from 'gen-proto-ts/teleport/userpreferences/v1/userpreferences_pb';
 
@@ -72,3 +73,45 @@ test('should convert the user preferences back to the old format when updating',
     actualUserPreferences.clusterPreferences.pinnedResources.resourceIds
   );
 });
+
+test('getCurrentTheme', () => {
+  mockMatchMediaWindow('dark');
+  let currentTheme = getCurrentTheme(Theme.UNSPECIFIED);
+  expect(currentTheme).toBe(Theme.DARK);
+
+  mockMatchMediaWindow('light');
+  currentTheme = getCurrentTheme(Theme.UNSPECIFIED);
+  expect(currentTheme).toBe(Theme.LIGHT);
+
+  currentTheme = getCurrentTheme(Theme.LIGHT);
+  expect(currentTheme).toBe(Theme.LIGHT);
+
+  currentTheme = getCurrentTheme(Theme.DARK);
+  expect(currentTheme).toBe(Theme.DARK);
+});
+
+test('getNextTheme', () => {
+  mockMatchMediaWindow('dark');
+  let nextTheme = getNextTheme(Theme.UNSPECIFIED);
+  expect(nextTheme).toBe(Theme.LIGHT);
+
+  mockMatchMediaWindow('light');
+  nextTheme = getNextTheme(Theme.UNSPECIFIED);
+  expect(nextTheme).toBe(Theme.DARK);
+
+  nextTheme = getNextTheme(Theme.LIGHT);
+  expect(nextTheme).toBe(Theme.DARK);
+
+  nextTheme = getNextTheme(Theme.DARK);
+  expect(nextTheme).toBe(Theme.LIGHT);
+});
+
+function mockMatchMediaWindow(prefers: 'light' | 'dark') {
+  return Object.defineProperty(window, 'matchMedia', {
+    writable: true,
+    value: jest.fn().mockImplementation(query => ({
+      matches: query === `(prefers-color-scheme: ${prefers})`,
+      media: query,
+    })),
+  });
+}