Object Oriented Programming Assessment

Welcome to your Object Oriented Programming Assessment! This is a tougher assessment than last time, but you know what's also tougher? You. You can do this, because all you have to do is your best.

Let's get started!

Remember to npm i to install dependencies.

Table of Contents

• Table of Contents
• Overview
  • What resources can you use?
  • Before you start
  • That's a lot of tests
  • Running tests effectively
• Section 0: Factory Functions
• Section 1: Has Many / Belongs To
• Section 2: Inheritance & Polymorphism
  • "Why can't I see my logs in the test?"

Overview

What resources can you use?

This is an open book assessment which means you can use the Marcy Docs and other internet resources. However, please do not talk to other fellows and do not use any AI resources. We need to see what you know from this assessment.

Before you start

Before you are 3 sections:

• Factory Functions
• Has Many / Belongs To
• Inheritance & Polymorphism

It's recommended that before you do anything, take a deep breath and let that useless adrenaline run out of you. Seriously, do that. Do it.

Ok, now that you're chill(er), it's time to start thinking about the assessment. It's always recommended that you scan over the entire thing before starting to code. This will let you see where you might run into big roadblocks or have speed boosts. This will help you plan your time more effectively.

That's a lot of tests

You're about to see a lot of tests. Do not panic. You got this!

Test files are often a few hundred lines due to their repetitive nature. Sure the file is 200 lines long, but each isolated test is only a 2-10 lines long. Just like you've seen a million times now.

A test will pass if the expect() statements inside are all successful. When reading a test, ask yourself

• What inputs is the test providing to my function?
• What is the expected output of my function?
• Are there any expected side effects?

How do you rock an assessment? One test at a time. Work small, test often, keep moving forward.

Running tests effectively

Did you run npm i yet?

The prompts are super lightweight because you need to be reading the tests. We recommend using npm run test:w. This will activate jest's "watch" mode, which automatically re-runs the tests on every file save.

Remember, while in watch mode if you hit w, a menu of options opens. These options allow you to focus on only running certain test or certain test files.

For example hitting p and then typing from-scratch it will only run tests from a file that matches that name. You can hit a to go back to running all tests.

Hit ctrl and c to exit watch mode.

You go this!

Section 0: Factory Functions

Remember this? In the 0-factory-function.js file, you'll find a bankAccountFactory function waiting for you.

This time, you won't be using classes. You'll be going back to day 1 of OOP and building a factory function that uses closure to keep its data private.

Your function should return an object with methods for manipulating that private data.

Section 1: Has Many / Belongs To

In this section, you must build 2 classes ToDoList and ToDoItem in the 1-has-many-belongs-to.js file. Your task is to create the basic properties and methods required for the relationship to work. The tests for these files are in 1-has-many-belongs-to.spec.js.

But wait, theres more!

You must add at least 1 instance method and property to each class. But feel free to add more! 1 each is just what the tests require. Get creative!

• In order to keep the primary tests passing, make sure that your custom properties come after the required parameters (if at all).
• Run your tests constantly to make sure you don't accidentally break anything, ok?

To be nice, we've kick started the code a little bit with an ID utils function.

Section 2: Inheritance & Polymorphism

Inside the 2-inheritance-polymorphism.js file you'll see 2 classes:

• A Phone class
• An AppleIPhone class

Your mission is to get all the tests to pass. There are a lot of tests and they'll tell you exactly what to build. Here are some tips for reading tests to write code:

• Read the test names! Those say what the test is looking for in plain english.
• What are the function signatures (what arguments do you need and what types of data do they expect)?
• Are the methods pure or do they rely on some internal state? Do they have side effects?
• Does the function console log? Return something? Both? Neither?? WHAT DOES IT DO?!
• Are your methods and properties spelled correctly?
• Do any classes inherit from any others?

"Why can't I see my logs in the test?"

Because we are testing how and when you use console.log, we are "mocking it" — we are taking control of it and changing its behavior.

So, console.log what you need to in order to pass the test; but if you want to see some extra debugging output, use console.info instead since we haven't overwritten that function.

OR! Just use the playground.js file to mess around, that will log everything like normal. Run that file with node playground.js.

Now get out there and good luck!