/*

SALES TAX

=========

A business requires a program that calculates how much the price of a product is including sales tax

Sales tax is 20% of the price of the product.

*/

function calculateSalesTax(sales) {

return sales * 1.2;

}

/*

CURRENCY FORMATTING

===================

The business has informed you that prices must have 2 decimal places

They must also start with the currency symbol

Write a function that adds tax to a number, and then transforms the total into the format £0.00

Remember that the prices must include the sales tax (hint: you already wrote a function for this!)

*/

function addTaxAndFormatCurrency(tax) {

let newPrice = calculateSalesTax(tax);

let showPrice = newPrice.toFixed(2);

return "£" + showPrice;

}

/*

===================================================

======= TESTS - DO NOT MODIFY BELOW THIS LINE =====

There are some Tests in this file that will help you work out if your code is working.

To run the tests for just this one file, type `npm test -- --testPathPattern 4-tax` into your terminal

(Reminder: You must have run `npm install` one time before this will work!)

===================================================

*/

test("calculateSalesTax for £15", () => {

expect(calculateSalesTax(15)).toEqual(18);

});

test("calculateSalesTax for £17.50", () => {

expect(calculateSalesTax(17.5)).toEqual(21);

});

test("calculateSalesTax for £34", () => {

expect(calculateSalesTax(34)).toEqual(40.8);

});

test("addTaxAndFormatCurrency for £15", () => {

expect(addTaxAndFormatCurrency(15)).toEqual("£18.00");

});

test("addTaxAndFormatCurrency for £17.50", () => {

expect(addTaxAndFormatCurrency(17.5)).toEqual("£21.00");

});

test("addTaxAndFormatCurrency for £34", () => {

expect(addTaxAndFormatCurrency(34)).toEqual("£40.80");

});