BEW 1.2 Day 9 challenges!
Fork this repo to begin.
Use the in-class-tdd project in this repo as a starting point. I recommend forking this starter repo directly to best keep track of your changes. Feel free to work with a partner.
The goal is to make each test pass before the end of the class period!
Imagine you just got a job with a MeasureIt.com. They want to create an app that measures everything. You'll need some methods that can return measurements.
- Area should return the area of a rectangle.
- Perimeter should return the perimeter of a rectangle.
- Should return the area of a circle with radius.
You'll start by writing pending tests for these methods. Then write functions that make the tests pass.
The product is a shopping cart. The cart will track products added to a cart. The cart needs to add new products, remove products, and provide the total count, and price of all products in the cart.
Start with these test cases and write code to answer test case. Note: there is no code yet that does any of the things the tests ask for.
From a TDD perspective, you start with failing tests and build the application to meet the requirements of the tests.
In terms of BDD, the test descriptions are written to describe what the product should be capable of doing.
it('Should create a new item with name and price');
it('Should return an array containing all items in cart');
it('Should add a new item to the shopping cart');
it('Should return the number of items in the cart');
it('Should remove items from cart');
// Stretch Challenges
it('Should update the count of items in the cart');
it('Should remove an item when its count is 0');
it('Should return the total cost of all items in the cart');Your goal is to write code that meets the above test cases.
To help visualize the how the cart behaves, you can picture the cart as a table. Imagine the tables below were drawn up by the design team to describe how the cart would work.
Imagine your shopping cart is empty:
| name | price | qty | cost |
|---|---|---|---|
Imagine you add an apple to the cart
| name | price | qty | cost |
|---|---|---|---|
| apple | 0.99 | 1 | 0.99 |
| total | 1 | 0.99 |
What if you add a banana?
| name | price | qty | cost |
|---|---|---|---|
| apple | 0.99 | 1 | 0.99 |
| banana | 1.29 | 1 | 1.29 |
| total | 2 | 2.28 |
What if you add another apple?
| name | price | qty | cost |
|---|---|---|---|
| apple | 0.99 | 2 | 1.98 |
| banana | 1.29 | 1 | 1.29 |
| total | 3 | 3.27 |
While you won't be making a functional shopping cart, you will have to create some of the system. Think about how shopping carts work. Ask yourself how the cart will keep track of items and what exactly an item is.
"Items" in the cart will be JavaScript Objects, and the "cart" system will hold them in an array.
- Set up your tests run your code. All tests should be pending.
- Solve each test case one at a time by following the TDD pattern.
- Write functions that handle the test case. The functions should return a value the test case can evaluate.
- Run your tests. If the first case passes move on to the next, if not revise your code and test again.
- Solving one test case may break a previously working case. In this case refactor and test again.
- Step by Step Setup - Quick documentation on how to get started with TDD and BDD in Node.
- Chai.js Cheatsheet - Awesome cheat sheet for implementing TDD and BDD!