foreach-map-filter.test.js

describe("#doubleValues", function() {
  it("doubles values in an array", function() {
    expect(doubleValues([1, 2, 3])).toEqual([2, 4, 6]);
  });
  it("works for negative numbers", function() {
    expect(doubleValues([1, -2, -3])).toEqual([2, -4, -6]);
  });
});

describe("#onlyEvenValues", function() {
  it("returns a new array of only even values", function() {
    expect(onlyEvenValues([1, 2, 3, 4, 5, 6])).toEqual([2, 4, 6]);
  });
});

describe("#showFirstAndLast", function() {
  it("returns an array of only the first and last characters in an array", function() {
    expect(showFirstAndLast(["elie", "colt", "matt", "tim"])).toEqual([
      "ee",
      "ct",
      "mt",
      "tm"
    ]);
  });
});

describe("#addKeyAndValue", function() {
  it("adds a key and value to an array of objects", function() {
    var arr = [
      { name: "Elie" },
      { name: "Tim" },
      { name: "Matt" },
      { name: "Colt" }
    ];
    var updatedArr = [
      { name: "Elie", title: "instructor" },
      { name: "Tim", title: "instructor" },
      { name: "Matt", title: "instructor" },
      { name: "Colt", title: "instructor" }
    ];
    expect(addKeyAndValue(arr, "title", "instructor")).toEqual(updatedArr);
  });
});

describe("#vowelCount", function() {
  it("returns an object with the keys as vowels and the values as the count", function() {
    expect(vowelCount("elie")).toEqual({ e: 2, i: 1 });
    expect(vowelCount("tim")).toEqual({ i: 1 });
    expect(vowelCount("matt")).toEqual({ a: 1 });
    expect(vowelCount("hmmm")).toEqual({});
    expect(vowelCount("i am awesome and so are you")).toEqual({
      i: 1,
      a: 4,
      e: 3,
      o: 3,
      u: 1
    });
  });
});

describe("#doubleValuesWithMap", function() {
  it("doubles values in an array", function() {
    expect(doubleValuesWithMap([1, 2, 3])).toEqual([2, 4, 6]);
  });
  it("works for negative numbers", function() {
    expect(doubleValuesWithMap([1, -2, -3])).toEqual([2, -4, -6]);
  });
});

describe("#valTimesIndex", function() {
  it("returns a new array with each value multiplied by the index", function() {
    expect(valTimesIndex([1, 2, 3])).toEqual([0, 2, 6]);
  });
  it("works for negative numbers", function() {
    expect(valTimesIndex([1, -2, -3])).toEqual([0, -2, -6]);
  });
});

describe("#extractKey", function() {
  it("returns a new array with the value of each key in an array objects", function() {
    var arr = [
      { name: "Elie" },
      { name: "Tim" },
      { name: "Matt" },
      { name: "Colt" }
    ];
    expect(extractKey(arr, "name")).toEqual(["Elie", "Tim", "Matt", "Colt"]);
  });
});

describe("#extractFulName", function() {
  var arr = [
    { first: "Elie", last: "Schoppik" },
    { first: "Tim", last: "Garcia" },
    { first: "Matt", last: "Lane" },
    { first: "Colt", last: "Steele" }
  ];
  it("returns a new array with the value of each key in an array objects", function() {
    expect(extractFullName(arr, "name")).toEqual([
      "Elie Schoppik",
      "Tim Garcia",
      "Matt Lane",
      "Colt Steele"
    ]);
  });
});

describe("#filterByValue", function() {
  var arr = [
    { first: "Elie", last: "Schoppik" },
    { first: "Tim", last: "Garcia", isCatOwner: true },
    { first: "Matt", last: "Lane" },
    { first: "Colt", last: "Steele", isCatOwner: true }
  ];
  it("returns a new array of objects that contain a key", function() {
    expect(filterByValue(arr, "isCatOwner")).toEqual([
      { first: "Tim", last: "Garcia", isCatOwner: true },
      { first: "Colt", last: "Steele", isCatOwner: true }
    ]);
  });
});

describe("#find", function() {
  var arr = [1, 2, 3, 4, 5];
  it("returns the first value found in an array", function() {
    expect(find(arr, 3)).toEqual(3);
  });
  it("returns undefined if the value is not found", function() {
    expect(find(arr, 10)).toEqual(undefined);
  });
});

describe("#findInObj", function() {
  var arr = [
    { first: "Elie", last: "Schoppik" },
    { first: "Tim", last: "Garcia", isCatOwner: true },
    { first: "Matt", last: "Lane" },
    { first: "Colt", last: "Steele", isCatOwner: true }
  ];
  it("returns the first value found in an array", function() {
    expect(findInObj(arr, "isCatOwner", true)).toEqual({
      first: "Tim",
      last: "Garcia",
      isCatOwner: true
    });
  });
  it("returns undefined if the value is not found", function() {
    expect(findInObj(arr, "isCatOwner", false)).toEqual(undefined);
  });
});

describe("#removeVowels", function() {
  it("removes all vowels from a string", function() {
    expect(removeVowels("elie")).toEqual("l");
    expect(removeVowels("TIM")).toEqual("tm");
    expect(removeVowels("ZZZZZZ")).toEqual("zzzzzz");
  });
});

describe("#doubleOddNumbers", function() {
  it("returns an array of all odd numbers doubled", function() {
    expect(doubleOddNumbers([1, 2, 3, 4, 5])).toEqual([2, 6, 10]);
    expect(doubleOddNumbers([4, 4, 4, 4, 4])).toEqual([]);
  });
});