So, what I have done in second period. For me the answer is very simple, MVP is completed in first phase which give me ample time to write test for the added feature and other function which is not tested earlier. In second Period I read lot of documentation of Jest. I have gone through each Matchers which is Provided by jest. Spent almost a week on reading it. After reading the documentation I feel very comfortable in writing test in jest. From my experience I would say don't dive in coding without knowing anything about the subject. First read the documentation of the following framework and become comfortable with the language. After that you will able to solve the problem in very less time. I have written around 10 test in this period which covers every aspect of the source code. I got stuck at the point where I have to write test for the generator function. I have to mock lot of data because It is the main function of source code which generates all the gatsby nodes initially. I also make some mistake. I am fetching data from the Plone CMS and then doing logging. I just forget that console log not print the nested array. So, I have made a huge mistake using console log. After lot of try I am not able to write test properly. I stuck in loop fixing one thing break another, after lot of afford I am able to solve this problem at 3am when I am going to bed after hectic day. I really enjoyed this phase a lot, I learned lot of new things and implemented it. I am very happy with myself what I am doing right now. In third phase I mainly write documentation and refactoring the code into small pieces of function so that It can enhance the readability of code.
If You find any thing interesting and anything which you want to ask, I will be happy to answer it :)