Mini-Challenge 2: Intro to Testing

README.md

Mini-Challenge 2: Intro to Testing

Answer the following questions first

1. Using create-react-app, what do we need to set up for testing?
2. What components are worth to test in your development?
3. Can you apply TDD once you already created components?

The Challenge

NOTE: Apply TDD as much as you can.

1. Find any sub-routine, extract that logic into a separate file and test it out.
2. Run test coverage and save results into a .txt file at ./ - root level. Can you make the total coverage to be above of 60%?

Acceptance Criteria

• Meaningful test cases were implemented for components and sub-routines logic.
• All the test cases were successful.

Bonus Points

• Test coverage is above 60%.

EDITED: Well, I wrote this time ago, but according to the readings, it is not possible, because it is a process you must start from the beginning... I'm not very sure about this, but I argue that it is possible because once you start writing a test, it is a new beginning, so, I say yes, authors say no... I don't know what to believe.

hey @cylcrow, it depends on one's perspective. I also think it is possible to start doing TDD for legacy code when building new features, fixing bugs and adding the new corresponding tests. The obvious reason here is that you are starting a new development.

For that code with no tests, you can think of the business logic already built at the code as a black box and write your unit tests, if something fails you can start from there applying TDD, but this scenario would start for sure with the approach "code-then-test".

😄 I knew it was possible. Thank you very much for sharing your experience. 🙏

1. create-react-app comes pre-built with testing tools, all you have to do is install them via NPM or Yarn.
2. For this challenge, i've tested fetching the API data and matching them on the HTML elements (like, title and description)
3. No, TDD is done during the development process, and not after. But you can always do standard testing after development if required.

1. Using create-react-app, what do we need to set up for testing?
   Nothing much since it already comes with Jest ready to start testing.
2. What components are worth testing in your development?
   In my opinion, the ones that have key features or are more dynamic when using the app, you need to keep in mind that you need to test
   that all renders properly and test the props and latest on those components
3. Can you apply TDD once you already created components?
   That depends on the perspective of each developer, in my opinion, yes, you can start doing TDD on code that was already written but is always good practice to do it starting the development process

1. Using create-react-app, what do we need to set up for testing?

I believe it already includes Jest, so we-re all set up!

2. What components are worth to test in your development?

I think that those that are going to deal with different kinds of inputs, specially those that come from the final user, are very important, so the events. Also checking that it renders properly, the props are passed correctly and the edge cases are quite worth the effort in my opinion.

3. Can you apply TDD once you already created components?

I don't think it can be done retroactively but, if needed, we can include it in further iterations of a product.