Add tests to check the entered code/logic.

[osioke]

Add JavaScript unit tests to check the logic/code created in tasks #6 and #7 work as expected.

This task depends on all the previous tasks, before it can be done.

To accept this task, assign yourself to the task using the Assignees option on the right of this description, and to complete this task, make a pull request with the solution-code, tag this issue, and mention your guide, so s/he will check and merge your solution. After which this task/issue will be closed and marked as done.

Also make sure to research and discuss the best ways to go about converting the images to HTML with your guide, using best practices.