1-weather-report.js

/*
    Imagine we're making a weather app!
    
    We have a list of cities that the user wants to track.
    We also already have a temperatureService function which will take a city as a parameter and return a temparature.

    Implement the function below:
        - take the array of cities as a parameter
        - return an array of strings, which is a statement about the temperature of each city.
            For example, "The temperature in London is 10 degrees"
        - Hint: you can call the temperatureService function from your function
*/

// 1. Create a new empty array
// 2. Loop through the cities, and for each city:
// a. Create a new string for the weather report of that city
// b. Add that new string into the array
// 3. Return the array

function getTemperatureReport(cities) {
    let arr = [];
    for (let city of cities) {
        let weatherReport = `The temperature in ${city} is ${temperatureService(city)} degrees`;
        arr.push(weatherReport);
    }
    return arr;
    // TODO
}


/* ======= TESTS - DO NOT MODIFY ===== */

function temperatureService(city) {
    let temparatureMap  = new Map();

    temparatureMap.set('London', 10);
    temparatureMap.set('Paris', 12);
    temparatureMap.set('Barcelona', 17);
    temparatureMap.set('Dubai', 27);
    temparatureMap.set('Mumbai', 29);
    temparatureMap.set('São Paulo', 23);
    temparatureMap.set('Lagos', 33);
    
    return temparatureMap.get(city);
}

test("should return array of same length as argument", () => {
    let usersCities = ["London", "Paris", "São Paulo"];
    expect(getTemperatureReport(usersCities).length).toEqual(3);
});

test("should return a temperature report for the user's cities", () => {
    let usersCities = [
        "London",
        "Paris",
        "São Paulo"
    ]

    expect(getTemperatureReport(usersCities)).toEqual([
        "The temperature in London is 10 degrees",
        "The temperature in Paris is 12 degrees",
        "The temperature in São Paulo is 23 degrees"
    ]);
});

test("should return a temperature report for the user's cities (alternate input)", () => {
    let usersCities = [
        "Barcelona",
        "Dubai"
    ]

    expect(getTemperatureReport(usersCities)).toEqual([
        "The temperature in Barcelona is 17 degrees",
        "The temperature in Dubai is 27 degrees"
    ]);
});

test("should return an empty array if the user hasn't selected any cities", () => {
    expect(getTemperatureReport([])).toEqual([]);
});