How to test dark mode implementation in Mediumish

Why testing matters

Adding dark mode to Mediumish is not just about switching colors; it affects typography, contrast, images, and user interactions. Without proper testing, you might end up with unreadable text, clashing colors, or broken layouts. Testing ensures a consistent, accessible, and user-friendly experience for all visitors.

Preparing for testing

Before you begin, make sure you have:

Preparation saves time and prevents overlooking critical areas during testing.

Manual testing process

Here’s a step-by-step approach for manual testing:

  1. Open the site in light mode, note its appearance, and then toggle to dark mode.
  2. Verify that background and text colors switch correctly without losing readability.
  3. Check UI components such as buttons, links, tables, and forms in both modes.
  4. Review images and media to ensure they are not overly dark in dark mode.
  5. Test toggling multiple times to confirm smooth transitions without flicker.

Manual testing helps you catch subtle visual issues that automated tools may miss.

Cross-browser and device testing

Dark mode may look different depending on rendering engines. Test on:

  • Browsers: Chrome, Firefox, Safari, Edge, Opera.
  • Devices: Desktop, tablet, and mobile.
  • Operating systems: Windows, macOS, iOS, Android.

Consider using online services like BrowserStack or LambdaTest to expand your testing coverage without owning every device.

Automated testing approach

While dark mode is primarily visual, some automated testing can help:

  • Use Cypress or Playwright to confirm that toggling updates the DOM and CSS classes correctly.
  • Integrate visual regression testing with tools like Percy or BackstopJS to detect unexpected style changes.
  • Set up unit tests for theme preference storage logic using Jest or Mocha.

Automation speeds up repetitive checks, especially after code updates.

Accessibility validation

Dark mode should maintain accessibility standards:

This ensures the feature benefits all users, including those relying on assistive technology.

Common bugs and fixes

Bug Possible Cause Solution
Text becomes unreadable in dark mode Low contrast between text and background Adjust color palette to meet accessibility guidelines
Toggle does not remember user preference Missing or incorrect localStorage logic Verify theme state is saved and loaded on page load
Images appear too dark Transparent backgrounds blending with dark background Add a light border or background behind images

Final checklist

  • Colors are readable and consistent in both modes.
  • All components adjust to the selected theme.
  • Toggle works instantly without lag or flicker.
  • User preference persists across sessions.
  • Accessibility requirements are met.
  • Feature works on all targeted browsers and devices.

Completing this checklist before launch minimizes the risk of user frustration.

FAQ

Q: Can I skip testing on older browsers?

A: If your audience data shows no usage, you can deprioritize them. However, be aware of potential complaints from outlier users.

Q: Do I need automated tests for dark mode?

A: Not strictly necessary, but they can save time in ongoing development and reduce regression risk.

Q: How often should I re-test dark mode?

A: Test after any design, CSS, or JavaScript changes, even if unrelated, to ensure compatibility.

Comments