import {
    flatten,
    getItemAtOppositeSideOfArray,
    getItemsToEitherSideOfArrayIndex,
} from './arrays';

describe('flatten', () => {
    test('Converts an array of arrays into a single array', () => {
        const initialArray = [
            [1, 2, 3],
            [4, 5, 6],
        ];

        const result = flatten(initialArray);

        expect(result).toEqual([1, 2, 3, 4, 5, 6]);
    });
});

describe('getItemsToEitherSide', () => {
    test('Gets the items to either side of an array index', () => {
        const initialArray = [
            0,
            1,
            2,
            3,
        ];

        const result = getItemsToEitherSideOfArrayIndex(
            initialArray,
            2,
        );

        expect(result).toEqual([1, 3]);
    });

    // tslint:disable-next-line
    test('Gets the items to either side of an array index when the index is 0', () => {
        const initialArray = [
            0,
            1,
            2,
            3,
        ];

        const result = getItemsToEitherSideOfArrayIndex(
            initialArray,
            0,
        );

        expect(result).toEqual([1, 3]);
    });

    // tslint:disable-next-line
    test('Gets the items to either side of an array index when the index is the last item', () => {
        const initialArray = [
            0,
            1,
            2,
            3,
        ];

        const result = getItemsToEitherSideOfArrayIndex(
            initialArray,
            initialArray.length - 1,
        );

        expect(result).toEqual([0, 2]);
    });
});

describe('getItemAtOppositeSideOfArray', () => {
    // tslint:disable-next-line
    test('Gets the item at the opposite side of the array when the index is 0', () => {
        const array = [
            0,
            1,
            2,
            3,
        ];

        const result = getItemAtOppositeSideOfArray(
            array,
            0,
        );

        expect(result).toBe(2);
    });

    // tslint:disable-next-line
    test('Gets the item at the opposite side of the array when the index is the midpoint', () => {
        const array = [
            0,
            1,
            2,
            3,
        ];

        const result = getItemAtOppositeSideOfArray(
            array,
            2,
        );

        expect(result).toBe(0);
    });

    // tslint:disable-next-line
    test('Gets the item at the opposite side of the array when the index is the last item', () => {
        const array = [
            0,
            1,
            2,
            3,
        ];

        const result = getItemAtOppositeSideOfArray(
            array,
            3,
        );

        expect(result).toBe(1);
    });
});