[Outreachy] Move existing tests to a unit testing framework

Hi;
My name is Luma, and  I wanted to take a moment to introduce myself
and share some
insights on an essential aspect of  avoiding pipes in git related
commands in test scripts.

I am an outreachy applicant for the December 2023 cohort and look
forward to learning from you.

One common practice in shell scripting is the use of pipes (|) to
chain multiple commands together.
 While pipes are incredibly versatile and useful, excessive use of
them can lead to script complexity.
I plan to avoid overusing pipes in test scripts by: leveraging command
options, using temporary files
and using functions and variables to break down complex pipelines.

If you have any questions on pipes, I'm always here to learn and share
knowledge.

Best regards,
Luma.