On the third week of my internship, I learnt on how to apply what I have learn so far. After setting up the sandbox application to practice the concepts like API, TDD and loose coupling. My task was to convert the stock threshold function of the existing app into an API. At the beginning, I was struggling to create the API for the stock threshold. After some guides from Mr Peter, I begin to understand on how to create the API.
Firstly, using the CQRS pattern, I separated the commands and the queries into separate files. In the queries folder contains the different Query which will return the entire list of the existing stock threshold to the user when it is called. Not only that, there’s also GetById Query which will return a stock threshold to the user based on the requested Id of the stock threshold.
Next, in the commands folder contains the create, update and delete functions for the stock threshold. The create command will take the item Id with the quantity for the stock threshold. Using the given item Id, the code will look for the item in the item database and map it to the stock threshold that was created.
Similar to the create command, the update command will take the stock threshold Id, item Id together with the quantity as well. In the update command, the code will take the item Id and check if the existing item Id is different with the inputted item Id. If the item Id is different, the code will look for the new item in the item database and update the existing item to the new one. As for the delete command, the user just has to input the stock threshold Id and the code will delete it. The Http method was implemented in the controller folder.
Lastly, the unit test was created for each of the function to make sure they are working properly. At the first, I was struggling to create the unit test as I was inexperience in creating unit test but after reference the other unit testing I was able to get the hang of it. The unit test was also accompany with some dummy data. All the unit test was able to pass without much problem.