solution.js

// 47: Set - basics (solution)
// To do: make all tests pass, leave the assert lines unchanged!

describe('`Set` lets you store unique values of any type', function(){

  it('`Set` is a new global constructor function', function() {
    assert.equal(typeof Set, 'function');
  });

  it('every value in a set is unique', function() {
    let set = new Set();

    set.add(1);
    set.add(2);
    const expectedSize = 2;

    assert.equal(set.size, expectedSize);
  });

  it('the string "1" is different to the number 1', function() {
    let set = new Set();
    set.add(1);
    set.add("1");

    assert.equal(set.size, 2);
  });

  it('even NaN is equal to NaN', function() {
    let set = new Set();
    set.add(NaN);
    set.add(NaN);

    assert.equal(set.size, 1);
  });

  it('+0 and -0 are seen as equal', function() {
    let set = new Set();
    set.add(+0);
    set.add(0);
    set.add(-0);

    assert.deepEqual([...set.values()], [+0]);
  });

});