Sum Function With Jest Unit Testing

GitHub Base Template for Jest Unit Testing (If you just want to download it directly)
https://github.com/mszucseducation/un...

Jest Documentation
https://jestjs.io/

Install
Step 1
npm init --y

Step 2
npm install --save-dev jest

Step 3
Add this to package.json:
```
{
"name": "examreviewunittesting",
"version": "1.0.0",
"description": "",
"main": "index.js",
"directories": {
"test": "test"
},
"scripts": {
"test": "jest --coverage"
},
"keywords": [],
"author": "",
"license": "ISC",
"devDependencies": {
"jest": "^29.3.1"
}
}
```

Step 4 (Optional if 'jest' cannot be recognized)
#### Windows
npm install jest -g

#### MAC
sudo npm install jest -g

Run the code using one of the following below:
Option 1
npm test

Option 2
jest

Option 3
npm test --coverage