dropdown.js

        '<a class="dropdown-item" href="#">Something else here</a>' +
        '<div class="divider"/>' +
        '<a class="dropdown-item" href="#">Another link</a>' +
        '</div>' +
        '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()
    var done = assert.async()
    var dropdownMenu = $dropdown.next()[0]

    $dropdown.parent('.dropdown')
      .on('shown.bs.dropdown', function () {
        // Popper.js add this attribute when we use it
        assert.strictEqual(dropdownMenu.getAttribute('x-placement'), null)
        done()
      })

    $dropdown[0].dispatchEvent(new Event('click'))
  })

  QUnit.test('should call Popper.js and detect navbar on update', function (assert) {
    assert.expect(3)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    dropdown.toggle()
    assert.ok(dropdown._popper)

    var spyPopper = sinon.spy(dropdown._popper, 'scheduleUpdate')
    var spyDetectNavbar = sinon.spy(dropdown, '_detectNavbar')
    dropdown.update()

    assert.ok(spyPopper.called)
    assert.ok(spyDetectNavbar.called)
  })

  QUnit.test('should just detect navbar on update', function (assert) {
    assert.expect(2)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    var spyDetectNavbar = sinon.spy(dropdown, '_detectNavbar')

    dropdown.update()

    assert.notOk(dropdown._popper)
    assert.ok(spyDetectNavbar.called)
  })

  QUnit.test('should dispose dropdown with Popper', function (assert) {
    assert.expect(6)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    dropdown.toggle()

    assert.ok(dropdown._popper)
    assert.ok(dropdown._menu !== null)
    assert.ok(dropdown._element !== null)
    var spyDestroy = sinon.spy(dropdown._popper, 'destroy')

    dropdown.dispose()

    assert.ok(spyDestroy.called)
    assert.ok(dropdown._menu === null)
    assert.ok(dropdown._element === null)
  })

  QUnit.test('should dispose dropdown', function (assert) {
    assert.expect(5)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])

    assert.notOk(dropdown._popper)
    assert.ok(dropdown._menu !== null)
    assert.ok(dropdown._element !== null)

    dropdown.dispose()

    assert.ok(dropdown._menu === null)
    assert.ok(dropdown._element === null)
  })

  QUnit.test('should hide dropdown', function (assert) {
    assert.expect(2)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    var done = assert.async()

    $dropdown
      .parent('.dropdown')
      .on('shown.bs.dropdown', function () {
        dropdown.hide()
      })
      .on('hide.bs.dropdown', function () {
        assert.ok(true, 'hide was fired')
      })
      .on('hidden.bs.dropdown', function () {
        assert.ok(!$dropdown.parent('.dropdown').hasClass('show'), 'dropdown menu is hidden')
        done()
      })

    dropdown.show()
  })

  QUnit.test('should not hide dropdown', function (assert) {
    assert.expect(1)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    $dropdown.trigger('click')
    dropdown.show()

    assert.ok($dropdown.parent('.dropdown').hasClass('show'), 'dropdown menu is still shown')
  })

  QUnit.test('should not show dropdown', function (assert) {
    assert.expect(1)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    dropdown.hide()
    assert.ok(!$dropdown.parent('.dropdown').hasClass('show'), 'dropdown menu is still hidden')
  })

  QUnit.test('should show dropdown', function (assert) {
    assert.expect(2)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    var done = assert.async()

    $dropdown
      .parent('.dropdown')
      .on('show.bs.dropdown', function () {
        assert.ok(true, 'show was fired')
      })
      .on('shown.bs.dropdown', function () {
        assert.ok($dropdown.parent('.dropdown').hasClass('show'), 'dropdown menu is shown')
        done()
      })

    dropdown.show()
  })

  QUnit.test('should prevent default event on show method call', function (assert) {
    assert.expect(1)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    var done = assert.async()

    $dropdown
      .parent('.dropdown')
      .on('show.bs.dropdown', function (event) {
        event.preventDefault()
        done()
      })

    dropdown.show()
    assert.ok(!$dropdown.parent('.dropdown').hasClass('show'), 'dropdown menu is hidden')
  })

  QUnit.test('should prevent default event on hide method call', function (assert) {
    assert.expect(1)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown()

    var dropdown = Dropdown._getInstance($dropdown[0])
    var done = assert.async()

    $dropdown
      .parent('.dropdown')
      .on('shown.bs.dropdown', function () {
        dropdown.hide()
      })
      .on('hide.bs.dropdown', function (event) {
        event.preventDefault()
        assert.ok($dropdown.parent('.dropdown').hasClass('show'), 'dropdown menu is shown')
        done()
      })

    dropdown.show()
  })

  QUnit.test('should not open dropdown via show method if target is disabled via attribute', function (assert) {
    assert.expect(1)
    var dropdownHTML =
        '<div class="dropdown">' +
        '  <button disabled href="#" class="btn dropdown-toggle" data-toggle="dropdown">Dropdown</button>' +
        '  <div class="dropdown-menu">' +
        '    <a class="dropdown-item" href="#">Another link</a>' +
        '  </div>' +
        '</div>'
    $(dropdownHTML).appendTo('#qunit-fixture')
    var $dropdown = $('#qunit-fixture').find('[data-toggle="dropdown"]').bootstrapDropdown()
    $dropdown.show()
    assert.ok(!$dropdown.parent('.dropdown').hasClass('show'))
  })

  QUnit.test('should not open dropdown via show method if target is disabled via class', function (assert) {
    assert.expect(1)
    var dropdownHTML =
        '<div class="dropdown">' +
        '  <button href="#" class="btn dropdown-toggle disabled" data-toggle="dropdown">Dropdown</button>' +
        '  <div class="dropdown-menu">' +
        '    <a class="dropdown-item" href="#">Another link</a>' +
        '  </div>' +
        '</div>'

    $(dropdownHTML).appendTo('#qunit-fixture')
    var $dropdown = $('#qunit-fixture').find('[data-toggle="dropdown"]').bootstrapDropdown()
    $dropdown.show()
    assert.ok(!$dropdown.parent('.dropdown').hasClass('show'))
  })

  QUnit.test('should not hide dropdown via hide method if target is disabled via attribute', function (assert) {
    assert.expect(1)
    var dropdownHTML =
        '<div class="dropdown show">' +
        '  <button disabled href="#" class="btn dropdown-toggle" data-toggle="dropdown">Dropdown</button>' +
        '  <div class="dropdown-menu">' +
        '    <a class="dropdown-item" href="#">Another link</a>' +
        '  </div>' +
        '</div>'
    $(dropdownHTML).appendTo('#qunit-fixture')
    var $dropdown = $('#qunit-fixture').find('[data-toggle="dropdown"]').bootstrapDropdown()
    $dropdown.hide()
    assert.ok($dropdown.parent('.dropdown').hasClass('show'))
  })

  QUnit.test('should not hide dropdown via hide method if target is disabled via class', function (assert) {
    assert.expect(1)
    var dropdownHTML =
        '<div class="dropdown show">' +
        '  <button href="#" class="btn dropdown-toggle disabled" data-toggle="dropdown">Dropdown</button>' +
        '  <div class="dropdown-menu">' +
        '    <a class="dropdown-item" href="#">Another link</a>' +
        '  </div>' +
        '</div>'

    $(dropdownHTML).appendTo('#qunit-fixture')
    var $dropdown = $('#qunit-fixture').find('[data-toggle="dropdown"]').bootstrapDropdown()
    $dropdown.hide()
    assert.ok($dropdown.parent('.dropdown').hasClass('show'))
  })

  QUnit.test('should create offset modifier correctly when offset option is a function', function (assert) {
    assert.expect(2)

    var getOffset = function (offsets) {
      return offsets
    }

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown({
        offset: getOffset
      })

    var dropdown = Dropdown._getInstance($dropdown[0])
    var offset = dropdown._getOffset()

    assert.ok(typeof offset.offset === 'undefined')
    assert.ok(typeof offset.fn === 'function')
  })

  QUnit.test('should create offset modifier correctly when offset option is not a function', function (assert) {
    assert.expect(2)

    var dropdownHTML =
      '<div class="dropdown">' +
      '  <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown</a>' +
      '  <div class="dropdown-menu">' +
      '    <a class="dropdown-item" href="#">Another link</a>' +
      '  </div>' +
      '</div>'

    var myOffset = 42
    var $dropdown = $(dropdownHTML)
      .appendTo('#qunit-fixture')
      .find('[data-toggle="dropdown"]')
      .bootstrapDropdown({
        offset: myOffset
      })

    var dropdown = Dropdown._getInstance($dropdown[0])
    var offset = dropdown._getOffset()

    assert.strictEqual(offset.offset, myOffset)
    assert.ok(typeof offset.fn === 'undefined')
  })

  QUnit.test('should return the version', function (assert) {
    assert.expect(1)
    assert.strictEqual(typeof Dropdown.VERSION, 'string')
  })
})