binaryHeapSpec.js

var expect = chai.expect
var binaryHeap

beforeEach(function(){
  binaryHeap = new MaxBinaryHeap
})

describe("#insert", function(){
  it("inserts a value at the correct position", function(){
    binaryHeap.insert(1)
    expect(binaryHeap.values[0]).to.equal(1)
    binaryHeap.insert(2)
    expect(binaryHeap.values[0]).to.equal(2)
    expect(binaryHeap.values).to.deep.equal([2, 1])
    binaryHeap.insert(3)
    expect(binaryHeap.values[0]).to.equal(3)
    expect(binaryHeap.values).to.deep.equal([3, 1, 2])
    binaryHeap.insert(4)
    expect(binaryHeap.values[0]).to.equal(4)
    expect(binaryHeap.values).to.deep.equal([4, 3, 2, 1])
    binaryHeap.insert(5)
    expect(binaryHeap.values[0]).to.equal(5)
    expect(binaryHeap.values).to.deep.equal([5, 4, 2, 1, 3])
    binaryHeap.insert(6)
    expect(binaryHeap.values[0]).to.equal(6)
    expect(binaryHeap.values).to.deep.equal([6, 4, 5, 1, 3, 2])
  });
});

describe("#remove", function(){
  it("removes a value at the correct position", function(){
    binaryHeap.insert(1)
    binaryHeap.insert(2)
    binaryHeap.insert(3)
    binaryHeap.insert(4)
    binaryHeap.insert(5)
    binaryHeap.insert(6)
    binaryHeap.remove()
    expect(binaryHeap.values[0]).to.equal(5)
    expect(binaryHeap.values).to.deep.equal([5,4,2,1,3])
    binaryHeap.remove()
    expect(binaryHeap.values).to.deep.equal([4,3,2,1])
    binaryHeap.remove()
    expect(binaryHeap.values).to.deep.equal([3,1,2])
  });
});

describe("#checkMaxHeap", function(){
    it("checks if an array is a valid max heap", function(){
    binaryHeap.insert(1)
    binaryHeap.insert(2)
    binaryHeap.insert(3)
    binaryHeap.insert(4)
    binaryHeap.insert(5)
    binaryHeap.insert(6)
    expect(checkMaxHeap(binaryHeap.values)).to.equal(true);
    let anArray = [1,2,3,4,5,6];
    expect(checkMaxHeap(anArray)).to.equal(false); 
    })
})

describe("#maxHeapify", function(){
  it("turns an array into a max binary heap", function(){
    var arr = maxHeapify([1,2,3,4,5,6,7,8,9,10])
    var arr2 = maxHeapify([5,-10,15,20,35,-2,-15,40,3,8,9])
    expect(checkMaxHeap(arr)).to.equal(true)
    expect(checkMaxHeap(arr2)).to.equal(true)
  });
});