Implement Jest Tests for Dummy JSON API

The Dummy JSON API currently lacks Jest tests. We need to add tests to ensure its functionality and reliability.

**Tasks:**

- Identify the key functionalities of Dummy JSON API.
- Write unit tests for:
- Component rendering
- User interactions
- Props and state management
- Write integration tests for:
- Any significant workflows (if applicable)
- Ensure all tests pass in the local environment and CI/CD pipeline.
- Update the documentation to include instructions on running the tests.

**Acceptance Criteria:**

- Jest tests for Dummy JSON API are created and passing.

**Additional Information:**

- Any known issues or specific areas of concern related to Dummy JSON API can be added here.

No files, tests, or entry points are named. Start by identifying the Dummy JSON API's key functionality and existing test setup, then define component, interaction, props/state, and applicable workflow coverage. Done means Jest tests pass locally and in CI/CD, with documentation explaining how to run them.

Written by the indexing model from the issue text.