rewrite tab unit tests

2 files changed, 860 insertions, 0 deletions

diff --git a/js/src/tab/tab.js b/js/src/tab/tab.js
new file mode 100644
index 000000000..e882ff1d2
--- /dev/null
+++ b/js/src/tab/tab.js
@@ -0,0 +1,267 @@
+/**
+ * --------------------------------------------------------------------------
+ * Bootstrap (v4.3.1): tab.js
+ * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
+ * --------------------------------------------------------------------------
+ */
+
+import {
+  jQuery as $,
+  TRANSITION_END,
+  emulateTransitionEnd,
+  getSelectorFromElement,
+  getTransitionDurationFromElement,
+  makeArray,
+  reflow
+} from '../util/index'
+import Data from '../dom/data'
+import EventHandler from '../dom/event-handler'
+import SelectorEngine from '../dom/selector-engine'
+
+/**
+ * ------------------------------------------------------------------------
+ * Constants
+ * ------------------------------------------------------------------------
+ */
+
+const NAME = 'tab'
+const VERSION = '4.3.1'
+const DATA_KEY = 'bs.tab'
+const EVENT_KEY = `.${DATA_KEY}`
+const DATA_API_KEY = '.data-api'
+
+const Event = {
+  HIDE: `hide${EVENT_KEY}`,
+  HIDDEN: `hidden${EVENT_KEY}`,
+  SHOW: `show${EVENT_KEY}`,
+  SHOWN: `shown${EVENT_KEY}`,
+  CLICK_DATA_API: `click${EVENT_KEY}${DATA_API_KEY}`
+}
+
+const ClassName = {
+  DROPDOWN_MENU: 'dropdown-menu',
+  ACTIVE: 'active',
+  DISABLED: 'disabled',
+  FADE: 'fade',
+  SHOW: 'show'
+}
+
+const Selector = {
+  DROPDOWN: '.dropdown',
+  NAV_LIST_GROUP: '.nav, .list-group',
+  ACTIVE: '.active',
+  ACTIVE_UL: ':scope > li > .active',
+  DATA_TOGGLE: '[data-toggle="tab"], [data-toggle="pill"], [data-toggle="list"]',
+  DROPDOWN_TOGGLE: '.dropdown-toggle',
+  DROPDOWN_ACTIVE_CHILD: ':scope > .dropdown-menu .active'
+}
+
+/**
+ * ------------------------------------------------------------------------
+ * Class Definition
+ * ------------------------------------------------------------------------
+ */
+
+class Tab {
+  constructor(element) {
+    this._element = element
+
+    Data.setData(this._element, DATA_KEY, this)
+  }
+
+  // Getters
+
+  static get VERSION() {
+    return VERSION
+  }
+
+  // Public
+
+  show() {
+    if (this._element.parentNode &&
+      this._element.parentNode.nodeType === Node.ELEMENT_NODE &&
+      this._element.classList.contains(ClassName.ACTIVE) ||
+      this._element.classList.contains(ClassName.DISABLED)) {
+      return
+    }
+
+    let target
+    let previous
+    const listElement = SelectorEngine.closest(this._element, Selector.NAV_LIST_GROUP)
+    const selector = getSelectorFromElement(this._element)
+
+    if (listElement) {
+      const itemSelector = listElement.nodeName === 'UL' || listElement.nodeName === 'OL' ? Selector.ACTIVE_UL : Selector.ACTIVE
+      previous = makeArray(SelectorEngine.find(itemSelector, listElement))
+      previous = previous[previous.length - 1]
+    }
+
+    let hideEvent = null
+
+    if (previous) {
+      hideEvent = EventHandler.trigger(previous, Event.HIDE, {
+        relatedTarget: this._element
+      })
+    }
+
+    const showEvent = EventHandler.trigger(this._element, Event.SHOW, {
+      relatedTarget: previous
+    })
+
+    if (showEvent.defaultPrevented ||
+      hideEvent !== null && hideEvent.defaultPrevented) {
+      return
+    }
+
+    if (selector) {
+      target = SelectorEngine.findOne(selector)
+    }
+
+    this._activate(
+      this._element,
+      listElement
+    )
+
+    const complete = () => {
+      EventHandler.trigger(previous, Event.HIDDEN, {
+        relatedTarget: this._element
+      })
+      EventHandler.trigger(this._element, Event.SHOWN, {
+        relatedTarget: previous
+      })
+    }
+
+    if (target) {
+      this._activate(target, target.parentNode, complete)
+    } else {
+      complete()
+    }
+  }
+
+  dispose() {
+    Data.removeData(this._element, DATA_KEY)
+    this._element = null
+  }
+
+  // Private
+
+  _activate(element, container, callback) {
+    const activeElements = container && (container.nodeName === 'UL' || container.nodeName === 'OL') ?
+      SelectorEngine.find(Selector.ACTIVE_UL, container) :
+      SelectorEngine.children(container, Selector.ACTIVE)
+
+    const active = activeElements[0]
+    const isTransitioning = callback &&
+      (active && active.classList.contains(ClassName.FADE))
+
+    const complete = () => this._transitionComplete(
+      element,
+      active,
+      callback
+    )
+
+    if (active && isTransitioning) {
+      const transitionDuration = getTransitionDurationFromElement(active)
+      active.classList.remove(ClassName.SHOW)
+
+      EventHandler.one(active, TRANSITION_END, complete)
+      emulateTransitionEnd(active, transitionDuration)
+    } else {
+      complete()
+    }
+  }
+
+  _transitionComplete(element, active, callback) {
+    if (active) {
+      active.classList.remove(ClassName.ACTIVE)
+
+      const dropdownChild = SelectorEngine.findOne(Selector.DROPDOWN_ACTIVE_CHILD, active.parentNode)
+
+      if (dropdownChild) {
+        dropdownChild.classList.remove(ClassName.ACTIVE)
+      }
+
+      if (active.getAttribute('role') === 'tab') {
+        active.setAttribute('aria-selected', false)
+      }
+    }
+
+    element.classList.add(ClassName.ACTIVE)
+    if (element.getAttribute('role') === 'tab') {
+      element.setAttribute('aria-selected', true)
+    }
+
+    reflow(element)
+
+    if (element.classList.contains(ClassName.FADE)) {
+      element.classList.add(ClassName.SHOW)
+    }
+
+    if (element.parentNode && element.parentNode.classList.contains(ClassName.DROPDOWN_MENU)) {
+      const dropdownElement = SelectorEngine.closest(element, Selector.DROPDOWN)
+
+      if (dropdownElement) {
+        makeArray(SelectorEngine.find(Selector.DROPDOWN_TOGGLE))
+          .forEach(dropdown => dropdown.classList.add(ClassName.ACTIVE))
+      }
+
+      element.setAttribute('aria-expanded', true)
+    }
+
+    if (callback) {
+      callback()
+    }
+  }
+
+  // Static
+
+  static _jQueryInterface(config) {
+    return this.each(function () {
+      const data = Data.getData(this, DATA_KEY) || new Tab(this)
+
+      if (typeof config === 'string') {
+        if (typeof data[config] === 'undefined') {
+          throw new TypeError(`No method named "${config}"`)
+        }
+
+        data[config]()
+      }
+    })
+  }
+
+  static _getInstance(element) {
+    return Data.getData(element, DATA_KEY)
+  }
+}
+
+/**
+ * ------------------------------------------------------------------------
+ * Data Api implementation
+ * ------------------------------------------------------------------------
+ */
+
+EventHandler.on(document, Event.CLICK_DATA_API, Selector.DATA_TOGGLE, function (event) {
+  event.preventDefault()
+
+  const data = Data.getData(this, DATA_KEY) || new Tab(this)
+  data.show()
+})
+
+/**
+ * ------------------------------------------------------------------------
+ * jQuery
+ * ------------------------------------------------------------------------
+ * add .tab to jQuery only if jQuery is present
+ */
+/* istanbul ignore if */
+if (typeof $ !== 'undefined') {
+  const JQUERY_NO_CONFLICT = $.fn[NAME]
+  $.fn[NAME] = Tab._jQueryInterface
+  $.fn[NAME].Constructor = Tab
+  $.fn[NAME].noConflict = () => {
+    $.fn[NAME] = JQUERY_NO_CONFLICT
+    return Tab._jQueryInterface
+  }
+}
+
+export default Tab
diff --git a/js/src/tab/tab.spec.js b/js/src/tab/tab.spec.js
new file mode 100644
index 000000000..3fae366d1
--- /dev/null
+++ b/js/src/tab/tab.spec.js
@@ -0,0 +1,593 @@
+import Tab from './tab'
+
+/** Test helpers */
+import { getFixture, clearFixture, jQueryMock } from '../../tests/helpers/fixture'
+
+describe('Tab', () => {
+  let fixtureEl
+
+  beforeAll(() => {
+    fixtureEl = getFixture()
+  })
+
+  afterEach(() => {
+    clearFixture()
+  })
+
+  describe('VERSION', () => {
+    it('should return plugin version', () => {
+      expect(Tab.VERSION).toEqual(jasmine.any(String))
+    })
+  })
+
+  describe('show', () => {
+    it('should activate element by tab id', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav">',
+        '  <li><a href="#home" role="tab">Home</a></li>',
+        '  <li><a id="triggerProfile" role="tab" href="#profile">Profile</a></li>',
+        '</ul>',
+        '<ul><li id="home"/><li id="profile"/></ul>'
+      ].join('')
+
+      const profileTriggerEl = fixtureEl.querySelector('#triggerProfile')
+      const tab = new Tab(profileTriggerEl)
+
+      profileTriggerEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelector('#profile').classList.contains('active')).toEqual(true)
+        expect(profileTriggerEl.getAttribute('aria-selected')).toEqual('true')
+        done()
+      })
+
+      tab.show()
+    })
+
+    it('should activate element by tab id in ordered list', done => {
+      fixtureEl.innerHTML = [
+        '<ol class="nav nav-pills">',
+        '  <li><a href="#home">Home</a></li>',
+        '  <li><a id="triggerProfile" href="#profile">Profile</a></li>',
+        '</ol>',
+        '<ol><li id="home"/><li id="profile"/></ol>'
+      ].join('')
+
+      const profileTriggerEl = fixtureEl.querySelector('#triggerProfile')
+      const tab = new Tab(profileTriggerEl)
+
+      profileTriggerEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelector('#profile').classList.contains('active')).toEqual(true)
+        done()
+      })
+
+      tab.show()
+    })
+
+    it('should activate element by tab id in nav list', done => {
+      fixtureEl.innerHTML = [
+        '<nav class="nav">',
+        '  <a href="#home">Home</a>',
+        '  <a id="triggerProfile" href="#profile">Profile</a>',
+        '</nav>',
+        '<nav><div id="home"></div><div id="profile"></div></nav>'
+      ].join('')
+
+      const profileTriggerEl = fixtureEl.querySelector('#triggerProfile')
+      const tab = new Tab(profileTriggerEl)
+
+      profileTriggerEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelector('#profile').classList.contains('active')).toEqual(true)
+        done()
+      })
+
+      tab.show()
+    })
+
+    it('should activate element by tab id in list group', done => {
+      fixtureEl.innerHTML = [
+        '<div class="list-group">',
+        '  <a href="#home">Home</a>',
+        '  <a id="triggerProfile" href="#profile">Profile</a>',
+        '</div>',
+        '<nav><div id="home"></div><div id="profile"></div></nav>'
+      ].join('')
+
+      const profileTriggerEl = fixtureEl.querySelector('#triggerProfile')
+      const tab = new Tab(profileTriggerEl)
+
+      profileTriggerEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelector('#profile').classList.contains('active')).toEqual(true)
+        done()
+      })
+
+      tab.show()
+    })
+
+    it('should not fire shown when show is prevented', done => {
+      fixtureEl.innerHTML = '<div class="nav"></div>'
+
+      const navEl = fixtureEl.querySelector('div')
+      const tab = new Tab(navEl)
+      const expectDone = () => {
+        setTimeout(() => {
+          expect().nothing()
+          done()
+        }, 30)
+      }
+
+      navEl.addEventListener('show.bs.tab', ev => {
+        ev.preventDefault()
+        expectDone()
+      })
+
+      navEl.addEventListener('shown.bs.tab', () => {
+        throw new Error('should not trigger shown event')
+      })
+
+      tab.show()
+    })
+
+    it('should not fire shown when tab is already active', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item"><a href="#home" class="nav-link active" role="tab">Home</a></li>',
+        '  <li class="nav-item"><a href="#profile" class="nav-link" role="tab">Profile</a></li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div class="tab-pane active" id="home" role="tabpanel"></div>',
+        '  <div class="tab-pane" id="profile" role="tabpanel"></div>',
+        '</div>'
+      ].join('')
+
+      const triggerActive = fixtureEl.querySelector('a.active')
+      const tab = new Tab(triggerActive)
+
+      triggerActive.addEventListener('shown.bs.tab', () => {
+        throw new Error('should not trigger shown event')
+      })
+
+      tab.show()
+      setTimeout(() => {
+        expect().nothing()
+        done()
+      }, 30)
+    })
+
+    it('should not fire shown when tab is disabled', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item"><a href="#home" class="nav-link active" role="tab">Home</a></li>',
+        '  <li class="nav-item"><a href="#profile" class="nav-link disabled" role="tab">Profile</a></li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div class="tab-pane active" id="home" role="tabpanel"></div>',
+        '  <div class="tab-pane" id="profile" role="tabpanel"></div>',
+        '</div>'
+      ].join('')
+
+      const triggerDisabled = fixtureEl.querySelector('a.disabled')
+      const tab = new Tab(triggerDisabled)
+
+      triggerDisabled.addEventListener('shown.bs.tab', () => {
+        throw new Error('should not trigger shown event')
+      })
+
+      tab.show()
+      setTimeout(() => {
+        expect().nothing()
+        done()
+      }, 30)
+    })
+
+    it('show and shown events should reference correct relatedTarget', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item"><a href="#home" class="nav-link active" role="tab">Home</a></li>',
+        '  <li class="nav-item"><a id="triggerProfile" href="#profile" class="nav-link" role="tab">Profile</a></li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div class="tab-pane active" id="home" role="tabpanel"></div>',
+        '  <div class="tab-pane" id="profile" role="tabpanel"></div>',
+        '</div>'
+      ].join('')
+
+      const secondTabTrigger = fixtureEl.querySelector('#triggerProfile')
+      const secondTab = new Tab(secondTabTrigger)
+
+      secondTabTrigger.addEventListener('show.bs.tab', ev => {
+        expect(ev.relatedTarget.hash).toEqual('#home')
+      })
+
+      secondTabTrigger.addEventListener('shown.bs.tab', ev => {
+        expect(ev.relatedTarget.hash).toEqual('#home')
+        expect(secondTabTrigger.getAttribute('aria-selected')).toEqual('true')
+        expect(fixtureEl.querySelector('a:not(.active)').getAttribute('aria-selected')).toEqual('false')
+        done()
+      })
+
+      secondTab.show()
+    })
+
+    it('should fire hide and hidden events', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav">',
+        '  <li><a href="#home">Home</a></li>',
+        '  <li><a href="#profile">Profile</a></li>',
+        '</ul>'
+      ].join('')
+
+      const triggerList = fixtureEl.querySelectorAll('a')
+      const firstTab = new Tab(triggerList[0])
+      const secondTab = new Tab(triggerList[1])
+
+      let hideCalled = false
+      triggerList[0].addEventListener('shown.bs.tab', () => {
+        secondTab.show()
+      })
+
+      triggerList[0].addEventListener('hide.bs.tab', ev => {
+        hideCalled = true
+        expect(ev.relatedTarget.hash).toEqual('#profile')
+      })
+
+      triggerList[0].addEventListener('hidden.bs.tab', ev => {
+        expect(hideCalled).toEqual(true)
+        expect(ev.relatedTarget.hash).toEqual('#profile')
+        done()
+      })
+
+      firstTab.show()
+    })
+
+    it('should not fire hidden when hide is prevented', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav">',
+        '  <li><a href="#home">Home</a></li>',
+        '  <li><a href="#profile">Profile</a></li>',
+        '</ul>'
+      ].join('')
+
+      const triggerList = fixtureEl.querySelectorAll('a')
+      const firstTab = new Tab(triggerList[0])
+      const secondTab = new Tab(triggerList[1])
+      const expectDone = () => {
+        setTimeout(() => {
+          expect().nothing()
+          done()
+        }, 30)
+      }
+
+      triggerList[0].addEventListener('shown.bs.tab', () => {
+        secondTab.show()
+      })
+
+      triggerList[0].addEventListener('hide.bs.tab', ev => {
+        ev.preventDefault()
+        expectDone()
+      })
+
+      triggerList[0].addEventListener('hidden.bs.tab', () => {
+        throw new Error('should not trigger hidden')
+      })
+
+      firstTab.show()
+    })
+
+    it('should handle removed tabs', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item">',
+        '    <a class="nav-link nav-tab" href="#profile" role="tab" data-toggle="tab">',
+        '      <button class="close"><span aria-hidden="true">&times;</span></button>',
+        '    </a>',
+        '  </li>',
+        '  <li class="nav-item">',
+        '    <a id="secondNav" class="nav-link nav-tab" href="#buzz" role="tab" data-toggle="tab">',
+        '      <button class="close"><span aria-hidden="true">&times;</span></button>',
+        '    </a>',
+        '  </li>',
+        '  <li class="nav-item">',
+        '    <a class="nav-link nav-tab" href="#references" role="tab" data-toggle="tab">',
+        '      <button id="btnClose" class="close"><span aria-hidden="true">&times;</span></button>',
+        '    </a>',
+        '  </li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div role="tabpanel" class="tab-pane fade show active" id="profile">test 1</div>',
+        '  <div role="tabpanel" class="tab-pane fade" id="buzz">test 2</div>',
+        '  <div role="tabpanel" class="tab-pane fade" id="references">test 3</div>',
+        '</div>'
+      ].join('')
+
+      const secondNavEl = fixtureEl.querySelector('#secondNav')
+      const btnCloseEl = fixtureEl.querySelector('#btnClose')
+      const secondNavTab = new Tab(secondNavEl)
+
+      secondNavEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelectorAll('.nav-tab').length).toEqual(2)
+        done()
+      })
+
+      btnCloseEl.addEventListener('click', () => {
+        const linkEl = btnCloseEl.parentNode
+        const liEl = linkEl.parentNode
+        const tabId = linkEl.getAttribute('href')
+        const tabIdEl = fixtureEl.querySelector(tabId)
+
+        liEl.parentNode.removeChild(liEl)
+        tabIdEl.parentNode.removeChild(tabIdEl)
+        secondNavTab.show()
+      })
+
+      btnCloseEl.click()
+    })
+  })
+
+  describe('dispose', () => {
+    it('should dispose a tab', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const el = fixtureEl.querySelector('div')
+      const tab = new Tab(fixtureEl.querySelector('div'))
+
+      expect(Tab._getInstance(el)).not.toBeNull()
+
+      tab.dispose()
+
+      expect(Tab._getInstance(el)).toBeNull()
+    })
+  })
+
+  describe('_jQueryInterface', () => {
+    it('should create a tab', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const div = fixtureEl.querySelector('div')
+
+      jQueryMock.fn.tab = Tab._jQueryInterface
+      jQueryMock.elements = [div]
+
+      jQueryMock.fn.tab.call(jQueryMock)
+
+      expect(Tab._getInstance(div)).toBeDefined()
+    })
+
+    it('should not re create a tab', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const div = fixtureEl.querySelector('div')
+      const tab = new Tab(div)
+
+      jQueryMock.fn.tab = Tab._jQueryInterface
+      jQueryMock.elements = [div]
+
+      jQueryMock.fn.tab.call(jQueryMock)
+
+      expect(Tab._getInstance(div)).toEqual(tab)
+    })
+
+    it('should call a tab method', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const div = fixtureEl.querySelector('div')
+      const tab = new Tab(div)
+
+      spyOn(tab, 'show')
+
+      jQueryMock.fn.tab = Tab._jQueryInterface
+      jQueryMock.elements = [div]
+
+      jQueryMock.fn.tab.call(jQueryMock, 'show')
+
+      expect(Tab._getInstance(div)).toEqual(tab)
+      expect(tab.show).toHaveBeenCalled()
+    })
+
+    it('should throw error on undefined method', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const div = fixtureEl.querySelector('div')
+      const action = 'undefinedMethod'
+
+      jQueryMock.fn.tab = Tab._jQueryInterface
+      jQueryMock.elements = [div]
+
+      try {
+        jQueryMock.fn.tab.call(jQueryMock, action)
+      } catch (error) {
+        expect(error.message).toEqual(`No method named "${action}"`)
+      }
+    })
+  })
+
+  describe('_getInstance', () => {
+    it('should return null if there is no instance', () => {
+      expect(Tab._getInstance(fixtureEl)).toEqual(null)
+    })
+
+    it('should return this instance', () => {
+      fixtureEl.innerHTML = '<div></div>'
+
+      const divEl = fixtureEl.querySelector('div')
+      const tab = new Tab(divEl)
+
+      expect(Tab._getInstance(divEl)).toEqual(tab)
+    })
+  })
+
+  describe('data-api', () => {
+    it('should create dynamicaly a tab', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item"><a href="#home" class="nav-link active" role="tab">Home</a></li>',
+        '  <li class="nav-item"><a id="triggerProfile" data-toggle="tab" href="#profile" class="nav-link" role="tab">Profile</a></li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div class="tab-pane active" id="home" role="tabpanel"></div>',
+        '  <div class="tab-pane" id="profile" role="tabpanel"></div>',
+        '</div>'
+      ].join('')
+
+      const secondTabTrigger = fixtureEl.querySelector('#triggerProfile')
+
+      secondTabTrigger.addEventListener('shown.bs.tab', () => {
+        expect(secondTabTrigger.classList.contains('active')).toEqual(true)
+        expect(fixtureEl.querySelector('#profile').classList.contains('active')).toEqual(true)
+        done()
+      })
+
+      secondTabTrigger.click()
+    })
+
+    it('selected tab should deactivate previous selected link in dropdown', () => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs">',
+        '  <li class="nav-item"><a class="nav-link" href="#home" data-toggle="tab">Home</a></li>',
+        '  <li class="nav-item"><a class="nav-link" href="#profile" data-toggle="tab">Profile</a></li>',
+        '  <li class="nav-item dropdown">',
+        '    <a class="nav-link dropdown-toggle active" data-toggle="dropdown" href="#">Dropdown</>',
+        '    <div class="dropdown-menu">',
+        '      <a class="dropdown-item active" href="#dropdown1" id="dropdown1-tab" data-toggle="tab">@fat</a>',
+        '      <a class="dropdown-item" href="#dropdown2" id="dropdown2-tab" data-toggle="tab">@mdo</a>',
+        '    </div>',
+        '  </li>',
+        '</ul>'
+      ].join('')
+
+      const firstLiLinkEl = fixtureEl.querySelector('li:first-child a')
+
+      firstLiLinkEl.click()
+      expect(firstLiLinkEl.classList.contains('active')).toEqual(true)
+      expect(fixtureEl.querySelector('li:last-child a').classList.contains('active')).toEqual(false)
+      expect(fixtureEl.querySelector('li:last-child .dropdown-menu a:first-child').classList.contains('active')).toEqual(false)
+    })
+
+    it('should handle nested tabs', done => {
+      fixtureEl.innerHTML = [
+        '<nav class="nav nav-tabs" role="tablist">',
+        '  <a id="tab1" href="#x-tab1" class="nav-item nav-link" data-toggle="tab" role="tab" aria-controls="x-tab1">Tab 1</a>',
+        '  <a href="#x-tab2" class="nav-item nav-link active" data-toggle="tab" role="tab" aria-controls="x-tab2" aria-selected="true">Tab 2</a>',
+        '  <a href="#x-tab3" class="nav-item nav-link" data-toggle="tab" role="tab" aria-controls="x-tab3">Tab 3</a>',
+        '</nav>',
+        '<div class="tab-content">',
+        '  <div class="tab-pane" id="x-tab1" role="tabpanel">',
+        '    <nav class="nav nav-tabs" role="tablist">',
+        '      <a href="#nested-tab1" class="nav-item nav-link active" data-toggle="tab" role="tab" aria-controls="x-tab1" aria-selected="true">Nested Tab 1</a>',
+        '      <a id="tabNested2" href="#nested-tab2" class="nav-item nav-link" data-toggle="tab" role="tab" aria-controls="x-profile">Nested Tab2</a>',
+        '    </nav>',
+        '    <div class="tab-content">',
+        '      <div class="tab-pane active" id="nested-tab1" role="tabpanel">Nested Tab1 Content</div>',
+        '      <div class="tab-pane" id="nested-tab2" role="tabpanel">Nested Tab2 Content</div>',
+        '    </div>',
+        '  </div>',
+        '  <div class="tab-pane active" id="x-tab2" role="tabpanel">Tab2 Content</div>',
+        '  <div class="tab-pane" id="x-tab3" role="tabpanel">Tab3 Content</div>',
+        '</div>'
+      ].join('')
+
+      const tab1El = fixtureEl.querySelector('#tab1')
+      const tabNested2El = fixtureEl.querySelector('#tabNested2')
+      const xTab1El = fixtureEl.querySelector('#x-tab1')
+
+      tabNested2El.addEventListener('shown.bs.tab', () => {
+        expect(xTab1El.classList.contains('active')).toEqual(true)
+        done()
+      })
+
+      tab1El.addEventListener('shown.bs.tab', () => {
+        expect(xTab1El.classList.contains('active')).toEqual(true)
+        tabNested2El.click()
+      })
+
+      tab1El.click()
+    })
+
+    it('should not remove fade class if no active pane is present', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item"><a id="tab-home" href="#home" class="nav-link" data-toggle="tab" role="tab">Home</a></li>',
+        '  <li class="nav-item"><a id="tab-profile" href="#profile" class="nav-link" data-toggle="tab" role="tab">Profile</a></li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div class="tab-pane fade" id="home" role="tabpanel"></div>',
+        '  <div class="tab-pane fade" id="profile" role="tabpanel"></div>',
+        '</div>'
+      ].join('')
+
+      const triggerTabProfileEl = fixtureEl.querySelector('#tab-profile')
+      const triggerTabHomeEl = fixtureEl.querySelector('#tab-home')
+      const tabProfileEl = fixtureEl.querySelector('#profile')
+      const tabHomeEl = fixtureEl.querySelector('#home')
+
+      triggerTabProfileEl.addEventListener('shown.bs.tab', () => {
+        expect(tabProfileEl.classList.contains('fade')).toEqual(true)
+        expect(tabProfileEl.classList.contains('show')).toEqual(true)
+
+        triggerTabHomeEl.addEventListener('shown.bs.tab', () => {
+          expect(tabProfileEl.classList.contains('fade')).toEqual(true)
+          expect(tabProfileEl.classList.contains('show')).toEqual(false)
+
+          expect(tabHomeEl.classList.contains('fade')).toEqual(true)
+          expect(tabHomeEl.classList.contains('show')).toEqual(true)
+
+          done()
+        })
+
+        triggerTabHomeEl.click()
+      })
+
+      triggerTabProfileEl.click()
+    })
+
+    it('should not add show class to tab panes if there is no `.fade` class', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item">',
+        '    <a class="nav-link nav-tab" href="#home" role="tab" data-toggle="tab">Home</a>',
+        '  </li>',
+        '  <li class="nav-item">',
+        '    <a id="secondNav" class="nav-link nav-tab" href="#profile" role="tab" data-toggle="tab">Profile</a>',
+        '  </li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div role="tabpanel" class="tab-pane" id="home">test 1</div>',
+        '  <div role="tabpanel" class="tab-pane" id="profile">test 2</div>',
+        '</div>'
+      ].join('')
+
+      const secondNavEl = fixtureEl.querySelector('#secondNav')
+
+      secondNavEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelectorAll('.show').length).toEqual(0)
+        done()
+      })
+
+      secondNavEl.click()
+    })
+
+    it('should add show class to tab panes if there is a `.fade` class', done => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav nav-tabs" role="tablist">',
+        '  <li class="nav-item">',
+        '    <a class="nav-link nav-tab" href="#home" role="tab" data-toggle="tab">Home</a>',
+        '  </li>',
+        '  <li class="nav-item">',
+        '    <a id="secondNav" class="nav-link nav-tab" href="#profile" role="tab" data-toggle="tab">Profile</a>',
+        '  </li>',
+        '</ul>',
+        '<div class="tab-content">',
+        '  <div role="tabpanel" class="tab-pane fade" id="home">test 1</div>',
+        '  <div role="tabpanel" class="tab-pane fade" id="profile">test 2</div>',
+        '</div>'
+      ].join('')
+
+      const secondNavEl = fixtureEl.querySelector('#secondNav')
+
+      secondNavEl.addEventListener('shown.bs.tab', () => {
+        expect(fixtureEl.querySelectorAll('.show').length).toEqual(1)
+        done()
+      })
+
+      secondNavEl.click()
+    })
+  })
+})