rover_test.js

describe('Mars Rover', () => {
    [
        {facing: 'N', endsFacing: 'E'},
        {facing: 'E', endsFacing: 'S'},
        {facing: 'S', endsFacing: 'W'},
        {facing: 'W', endsFacing: 'N'}
    ].forEach(({facing, endsFacing}) => {
        it('turns right from ${facing} to ${endsFacing}', () => {
            let rover = {facing: facing};
            rover = exec(rover, 'R');
            assert.equal(rover.facing, endsFacing);
        });
    });

    [
        {facing: 'N', endsFacing: 'W'},
        {facing: 'W', endsFacing: 'S'},
        {facing: 'S', endsFacing: 'E'},
        {facing: 'E', endsFacing: 'N'}
    ].forEach(({facing, endsFacing}) => {
        it('turns right from ${facing} to ${endsFacing}', () => {
            let rover = {facing: facing};
            rover = exec(rover, 'L');
            assert.equal(rover.facing, endsFacing);
        });
    });

    [
        {facing: 'N', x: 5, y: 6},
        {facing: 'E', x: 6, y: 5},
        {facing: 'S', x: 5, y: 4},
        {facing: 'W', x: 4, y: 5}
    ].forEach(({facing, x, y}) => {
        it('moves forward in direction ${facing}', () => {
            let rover = {facing: facing, position: {x: 5, y: 5}};
            rover = exec(rover, 'F');
            assert.deepEqual(rover.position, {x: x, y: y});
        });
    });

    [
        {facing: 'N', x: 5, y: 4},
        {facing: 'E', x: 4, y: 5},
        {facing: 'S', x: 5, y: 6},
        {facing: 'W', x: 6, y: 5}
    ].forEach(({facing, x, y}) => {
        it('moves forward in direction ${facing}', () => {
            let rover = {facing: facing, position: {x: 5, y: 5}};
            rover = exec(rover, 'B');
            assert.deepEqual(rover.position, {x: x, y: y});
        });
    });

    it('executes a sequence of instructions', () => {
        let rover = {facing: 'N'};
        rover = exec(rover, 'RR');
        assert.equal(rover.facing, 'S');
    });