AboutApplyingWhatWeHaveLearnt.js

var _; //globals

describe("About Applying What We Have Learnt", function() {

  var products;

  beforeEach(function () { 
    products = [
       { name: "Sonoma", ingredients: ["artichoke", "sundried tomatoes", "mushrooms"], containsNuts: false },
       { name: "Pizza Primavera", ingredients: ["roma", "sundried tomatoes", "goats cheese", "rosemary"], containsNuts: false },
       { name: "South Of The Border", ingredients: ["black beans", "jalapenos", "mushrooms"], containsNuts: false },
       { name: "Blue Moon", ingredients: ["blue cheese", "garlic", "walnuts"], containsNuts: true },
       { name: "Taste Of Athens", ingredients: ["spinach", "kalamata olives", "sesame seeds"], containsNuts: true }
    ];
  });

  /*********************************************************************************/

  it("given I'm allergic to nuts and hate mushrooms, it should find a pizza I can eat (imperative)", function () {

    var i,j,hasMushrooms, productsICanEat = [];

    for (i = 0; i < products.length; i+=1) {
        if (products[i].containsNuts === false) {
            hasMushrooms = false;
            for (j = 0; j < products[i].ingredients.length; j+=1) {
               if (products[i].ingredients[j] === "mushrooms") {
                  hasMushrooms = true;
               }
            }
            if (!hasMushrooms) productsICanEat.push(products[i]);
        }
    }

    expect(productsICanEat.length).toBe(1);
  });

  it("given I'm allergic to nuts and hate mushrooms, it should find a pizza I can eat (functional)", function () {

      var productsICanEat = [];

      /* solve using filter() & all() / any() */
 
      function filterBadIngredients () {
          //takes variable args, but for this example it only filters for nuts and mushrooms.
          for (var i = 0; i < products.length; i++) {
              hasBadIngredient = false;
              for (var j = 0; j < arguments.length; j++) {
                  if (arguments[j] === "nuts" && products[i].containsNuts === true) {
                      hasBadIngredient = true;
                  } else if (_(products[i]).filter(function (x){ return x === arguments[j]})) {
                      hasBadIngredient = true;
                  }
                  if (!hasBadIngredient) {productsICanEat.push(products[i])}
              }
	  }
      
     hasBadIngredient("nuts", "mushrooms");    
     expect(productsICanEat.length).toBe(1);
      }
  });

  /*********************************************************************************/

  it("should add all the natural numbers below 1000 that are multiples of 3 or 5 (imperative)", function () {
    
    var sum = 0;
    for(var i=1; i<1000; i+=1) {
      if (i % 3 === 0 || i % 5 === 0) {
        sum += i;
      }
    }
    
    expect(sum).toBe(233168);
  });

  it("should add all the natural numbers below 1000 that are multiples of 3 or 5 (functional)", function () {
    var sum = _(_.range(0, 1000)).chain()
	  .filter(function (x) {return x % 5 === 0 || x % 3 === 0})
	  .reduce(function (memo, x) {return memo + x}, 0)
	  .value()
    /* try chaining range() and reduce() */

    expect(233168).toBe(sum);
  });

  /*********************************************************************************/
   it("should count the ingredient occurrence (imperative)", function () {
    var ingredientCount = { "{ingredient name}": 0 };

    for (i = 0; i < products.length; i+=1) {
        for (j = 0; j < products[i].ingredients.length; j+=1) {
            ingredientCount[products[i].ingredients[j]] = (ingredientCount[products[i].ingredients[j]] || 0) + 1;
        }
    }

    expect(ingredientCount['mushrooms']).toBe(2);
  });

  it("should count the ingredient occurrence (functional)", function () {
    var ingredientCount = 

    /* chain() together map(), flatten() and reduce() */
    _(products).chain()
	  .map(function(name) { 
		return name.ingredients;})
	  .flatten()
	  .reduce(function(ingredientCount, i) {
		  ingredientCount[i] = (ingredientCount[i] || 0) + 1;
		  return ingredientCount}, {}).value();

    expect(ingredientCount['mushrooms']).toBe(2);
  });

/*********************************************************************************/
  /* UNCOMMENT FOR EXTRA CREDIT */

/* Extra Credit 1 */  
  it("should find the largest prime factor of a composite number", function () {
    //Should factorize to 2^2x3x13
	var factorThis = _([156]).chain() 
	  .reduce(function (factorThis, n) {
		console.log("Trying to factor " + factorThis[n]);
	    var d = 2; //divisor for factoring
		while (factorThis[n] > 1) {
		  while (factorThis[n]%d===0) {
		    factorThis.push(d); 
		    factorThis[n] = factorThis[n] / d;
			console.log("Factors added: " + factorThis[n] + ", " + d);
		  }
	      d = d + 1;
		}
	    console.log(factorThis);
	    return factorThis;
	  }).value();
  expect(factorThis[-1]).toBe(13);
  });


  /*
  it("should find the largest palindrome made from the product of two 3 digit numbers", function () {
    
  });

  it("should find the smallest number divisible by each of the numbers 1 to 20", function () {
      
    
  });

  it("should find the difference between the sum of the squares and the square of the sums", function () {
    
  });

  it("should find the 10001st prime", function () {

  });
  */
});