examples of testing with jasmine

gistfile1.js

function multiply(a, b) {
  return a * b;
}

function divide(a, b) {
  if (b === 0) {
    throw "Don't try to divide by zero!";
  }

  return Math.round(a / b);
}

function createList(items) {
  var list = $('<ul/>');

  $.each(items, function(i, item) {
    if (typeof item !== 'string') { return; }
    list.append(
      $('<li>' + item + '</li>')
        .click(function() {
          $(this).addClass('clicked');
        })
    );
  });

  return list;
}

gistfile2.js

describe("multiply", function() {
  it("should return the product of two numbers", function() {
    expect(multiply(2,3)).toEqual(6);
    expect(multiply(-1,1)).toEqual(-1);
    expect(multiply(1,0)).toEqual(0);
    expect(multiply(-1,-1)).toEqual(1);
  });
});

gistfile3.js

describe("divide", function() {
  it("should return the value of a / b", function() {
    expect(divide(3,3)).toEqual(1);
    expect(divide(6,2)).toEqual(3);
  });

  it("should throw an error if you try to divide by 0", function() {
    expect(function() { divide(1,0); }).toThrow();
  });
});

gistfile4.js

describe("createList", function() {
  var items = [ 'apple', 'orange', 'pear' ];

  it("should return a jquery object containing an unordered list", function() {
    var list = createList(items);
    expect(list).toBeDefined();
    expect(list.jquery).toBeDefined();
    expect(list.length).toBe(1);
    expect(list[0].nodeName.toLowerCase()).toBe('ul');
  });

  it("should contain the correct number of list items", function() {
    var list = createList(items);
    expect(list.children().length).toBe(3);
    expect(list.children('li').length).toBe(list.children().length);
  });

  it("should properly populate the list items", function() {
    var list = createList(items);
    expect(list.children().eq(1).html()).toEqual('orange');
  });

  it("should only use an item if it is a string", function() {
    var list = createList([ 'apple', 1, false, {}, [], 'pear' ]);
    expect(list.children().length).toBe(2);
  });

  it("should add a click handler to its list items that adds a class of 'clicked'", function() {
    var list = createList(items),
        li = list.find('li').click();

    expect(li.hasClass('clicked')).toBeTruthy();
  });

  /*
  it("should only use items that are at least three characters long", function() {
    var list = createList([ 'a', 'long enough' ]);
    expect(list.children().length).toBe(1);
  });
  */
});

gistfile5.txt

Thank you Rebecca, I've learned a lot from your example!
However I changed this, to be cleaner:

expect(list[0].nodeName.toLowerCase()).toBe('ul');
expect(list.attr("nodeName")).toBe("UL");

Hi Rebecca,
now I see your tutorial, have a better idea about unit testing!

Thanks Rebecca!