Scheme - add isDarkMode function (#2847)

Author: Inbal-Tish

src/style/__tests__/scheme.spec.js

@@ -105,4 +105,15 @@ describe('Scheme', () => {
       expect(listener).toHaveBeenCalledTimes(1);
     });
   });
+
+  describe('isDarkMode', () => {
+    it('should return false when app is on light mode', () => {
+      expect(Scheme.isDarkMode()).toBe(false);
+    });
+
+    it('should return true when app is on dark mode', () => {
+      Scheme.setScheme('dark');
+      expect(Scheme.isDarkMode()).toBe(true);
+    });
+  });
 });

src/style/colors.ts

@@ -177,7 +177,7 @@ export class Colors {
     return validColors ? undefined : results[0];
   }
 
-  shouldReverseOnDark = (avoidReverseOnDark?: boolean) => !avoidReverseOnDark && this.shouldSupportDarkMode && Scheme.getSchemeType() === 'dark';
+  shouldReverseOnDark = (avoidReverseOnDark?: boolean) => !avoidReverseOnDark && this.shouldSupportDarkMode && Scheme.isDarkMode();
 
   getColorTint(colorValue: string | OpaqueColorValue, tintKey: string | number, options: GetColorTintOptions = {}) {
     if (_.isUndefined(tintKey) || isNaN(tintKey as number) || _.isUndefined(colorValue)) {

src/style/scheme.ts

@@ -32,6 +32,13 @@ class Scheme {
     return scheme ?? 'light';
   }
 
+  /** 
+   * Whether the app's scheme is 'dark', i.e. is on dark mode
+   */
+  isDarkMode() {
+    return this.getSchemeType() === 'dark';
+  }
+
   /**
    * Set color scheme for app
    * arguments: