odin-javascript-exercises/02_repeatString/repeatString.spec.js

const repeatString = require('./repeatString')

describe('repeatString', () => {
    test('repeats the string', () => {
        expect(repeatString('hey', 3)).toEqual('heyheyhey');
    });
    test('repeats the string many times', () => {
        expect(repeatString('hey', 10)).toEqual('heyheyheyheyheyheyheyheyheyhey');
    });
    test('repeats the string 1 times', () => {
        expect(repeatString('hey', 1)).toEqual('hey');
    });
    test('repeats the string 0 times', () => {
        expect(repeatString('hey', 0)).toEqual('');
    });
    test('returns ERROR with negative numbers', () => {
        expect(repeatString('hey', -1)).toEqual('ERROR');
    });
    // noinspection SpellCheckingInspection,GrazieInspection
    test('repeats the string a random amount of times', function () {
        /*The number is generated by using Math.random to get a value from
        between 0 and 1, when this is multiplied by 1000 and rounded down with
        Math.floor it equals a number between 0 and 999 (this number will change
        everytime you run the test).*/

        // DO NOT use Math.floor(Math.random() * 1000) in your code,
        // this test generates a random number, then passes it into your code
        // with a function parameter.
        // If this doesn't make sense, you should go read about functions here:
        // https://www.theodinproject.com/paths/foundations/courses/foundations/lessons/fundamentals-part-3
        const number = Math.floor(Math.random() * 1000)
        /*The .match(/((hey))/g).length is a regex that will count the number of
        heys in the result, which if your function works correctly will equal
        the number that was randomly generated. */
        expect(repeatString('hey', number).match(/(hey)/g).length)
            .toEqual(number);
    });
    test('works with blank strings', () => {
        expect(repeatString('', 10)).toEqual('');
    });
});