Revamp tabs & follow ARIA 1.1 practices (#33079)

* Tab: Revamp tab.js & add support Aria features

* Tab: Add tab support, just to keep backwards compatibility. Better to remove it on v6

* Revert "Tab: Add tab support, just to keep backwards compatibility. Better to remove it on v6"

* Support arrow down/up functionality

* add prevent default to avoid scrolling the page during up/down keys handling

* remove panel tabindex handling

* Expand documentation text for JS plugin

* Rearrange new docs to specifically call out a11y

* properly place section

Co-authored-by: XhmikosR <xhmikosr@gmail.com>
Co-authored-by: Patrick H. Lauke <redux@splintered.co.uk>
Co-authored-by: Mark Otto <markdotto@gmail.com>

2 files changed, 394 insertions, 113 deletions

diff --git a/js/src/tab.js b/js/src/tab.js
index f9969fb7a4..135e929dda 100644
--- a/js/src/tab.js
+++ b/js/src/tab.js
@@ -5,7 +5,7 @@
  * --------------------------------------------------------------------------
  */
 
-import { defineJQueryPlugin, getElementFromSelector, isDisabled, reflow } from './util/index'
+import { defineJQueryPlugin, getElementFromSelector, getNextActiveElement, isDisabled } from './util/index'
 import EventHandler from './dom/event-handler'
 import SelectorEngine from './dom/selector-engine'
 import BaseComponent from './base-component'
@@ -17,158 +17,264 @@ import BaseComponent from './base-component'
 const NAME = 'tab'
 const DATA_KEY = 'bs.tab'
 const EVENT_KEY = `.${DATA_KEY}`
-const DATA_API_KEY = '.data-api'
 
 const EVENT_HIDE = `hide${EVENT_KEY}`
 const EVENT_HIDDEN = `hidden${EVENT_KEY}`
 const EVENT_SHOW = `show${EVENT_KEY}`
 const EVENT_SHOWN = `shown${EVENT_KEY}`
-const EVENT_CLICK_DATA_API = `click${EVENT_KEY}${DATA_API_KEY}`
+const EVENT_CLICK_DATA_API = `click${EVENT_KEY}`
+const EVENT_KEYDOWN = `keydown${EVENT_KEY}`
+const EVENT_LOAD_DATA_API = `load${EVENT_KEY}`
+
+const ARROW_LEFT_KEY = 'ArrowLeft'
+const ARROW_RIGHT_KEY = 'ArrowRight'
+const ARROW_UP_KEY = 'ArrowUp'
+const ARROW_DOWN_KEY = 'ArrowDown'
 
-const CLASS_NAME_DROPDOWN_MENU = 'dropdown-menu'
 const CLASS_NAME_ACTIVE = 'active'
 const CLASS_NAME_FADE = 'fade'
 const CLASS_NAME_SHOW = 'show'
+const CLASS_DROPDOWN = 'dropdown'
 
-const SELECTOR_DROPDOWN = '.dropdown'
-const SELECTOR_NAV_LIST_GROUP = '.nav, .list-group'
-const SELECTOR_ACTIVE = '.active'
-const SELECTOR_ACTIVE_UL = ':scope > li > .active'
-const SELECTOR_DATA_TOGGLE = '[data-bs-toggle="tab"], [data-bs-toggle="pill"], [data-bs-toggle="list"]'
 const SELECTOR_DROPDOWN_TOGGLE = '.dropdown-toggle'
-const SELECTOR_DROPDOWN_ACTIVE_CHILD = ':scope > .dropdown-menu .active'
+const SELECTOR_DROPDOWN_MENU = '.dropdown-menu'
+const SELECTOR_DROPDOWN_ITEM = '.dropdown-item'
+const NOT_SELECTOR_DROPDOWN_TOGGLE = ':not(.dropdown-toggle)'
+
+const SELECTOR_TAB_PANEL = '.list-group, .nav, [role="tablist"]'
+const SELECTOR_OUTER = '.nav-item, .list-group-item'
+const SELECTOR_INNER = `.nav-link${NOT_SELECTOR_DROPDOWN_TOGGLE}, .list-group-item${NOT_SELECTOR_DROPDOWN_TOGGLE}, [role="tab"]${NOT_SELECTOR_DROPDOWN_TOGGLE}`
+const SELECTOR_DATA_TOGGLE = '[data-bs-toggle="tab"], [data-bs-toggle="pill"], [data-bs-toggle="list"]' // todo:v6: could be only `tab`
+const SELECTOR_INNER_ELEM = `${SELECTOR_INNER}, ${SELECTOR_DATA_TOGGLE}`
+
+const SELECTOR_DATA_TOGGLE_ACTIVE = `.${CLASS_NAME_ACTIVE}[data-bs-toggle="tab"], .${CLASS_NAME_ACTIVE}[data-bs-toggle="pill"], .${CLASS_NAME_ACTIVE}[data-bs-toggle="list"]`
 
 /**
  * Class definition
  */
 
 class Tab extends BaseComponent {
+  constructor(element) {
+    super(element)
+    this._parent = this._element.closest(SELECTOR_TAB_PANEL)
+
+    if (!this._parent) {
+      return
+      // todo: should Throw exception on v6
+      // throw new TypeError(`${element.outerHTML} has not a valid parent ${SELECTOR_INNER_ELEM}`)
+    }
+
+    // Set up initial aria attributes
+    this._setInitialAttributes(this._parent, this._getChildren())
+
+    EventHandler.on(this._element, EVENT_KEYDOWN, event => this._keydown(event))
+  }
+
   // Getters
   static get NAME() {
     return NAME
   }
 
   // Public
-  show() {
-    if (this._element.parentNode &&
-      this._element.parentNode.nodeType === Node.ELEMENT_NODE &&
-      this._element.classList.contains(CLASS_NAME_ACTIVE)) {
+  show() { // Shows this elem and deactivate the active sibling if exists
+    const innerElem = this._element
+    if (this._elemIsActive(innerElem)) {
       return
     }
 
-    const target = getElementFromSelector(this._element)
-    const listElement = this._element.closest(SELECTOR_NAV_LIST_GROUP)
-    let previous
+    // Search for active tab on same parent to deactivate it
+    const active = this._getActiveElem()
 
-    if (listElement) {
-      const itemSelector = listElement.nodeName === 'UL' || listElement.nodeName === 'OL' ? SELECTOR_ACTIVE_UL : SELECTOR_ACTIVE
-      previous = SelectorEngine.find(itemSelector, listElement)
-      previous = previous[previous.length - 1]
-    }
-
-    const hideEvent = previous ?
-      EventHandler.trigger(previous, EVENT_HIDE, { relatedTarget: this._element }) :
+    const hideEvent = active ?
+      EventHandler.trigger(active, EVENT_HIDE, { relatedTarget: innerElem }) :
       null
 
-    const showEvent = EventHandler.trigger(this._element, EVENT_SHOW, { relatedTarget: previous })
+    const showEvent = EventHandler.trigger(innerElem, EVENT_SHOW, { relatedTarget: active })
 
-    if (showEvent.defaultPrevented || (hideEvent !== null && hideEvent.defaultPrevented)) {
+    if (showEvent.defaultPrevented || (hideEvent && hideEvent.defaultPrevented)) {
       return
     }
 
-    this._activate(this._element, listElement)
+    this._deactivate(active, innerElem)
+    this._activate(innerElem, active)
+  }
 
-    const complete = () => {
-      EventHandler.trigger(previous, EVENT_HIDDEN, { relatedTarget: this._element })
-      EventHandler.trigger(this._element, EVENT_SHOWN, { relatedTarget: previous })
+  // Private
+  _activate(element, relatedElem) {
+    if (!element) {
+      return
     }
 
-    if (target) {
-      this._activate(target, target.parentNode, complete)
-    } else {
-      complete()
-    }
-  }
+    element.classList.add(CLASS_NAME_ACTIVE)
 
-  // 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)
+    this._activate(getElementFromSelector(element)) // Search and activate/show the proper section
 
-    const active = activeElements[0]
-    const isTransitioning = callback && (active && active.classList.contains(CLASS_NAME_FADE))
+    const isAnimated = element.classList.contains(CLASS_NAME_FADE)
+    const complete = () => {
+      if (isAnimated) { // todo: maybe is redundant
+        element.classList.add(CLASS_NAME_SHOW)
+      }
 
-    const complete = () => this._transitionComplete(element, active, callback)
+      if (element.getAttribute('role') !== 'tab') {
+        return
+      }
 
-    if (active && isTransitioning) {
-      active.classList.remove(CLASS_NAME_SHOW)
-      this._queueCallback(complete, element, true)
-    } else {
-      complete()
+      element.focus()
+      element.removeAttribute('tabindex')
+      element.setAttribute('aria-selected', true)
+      this._toggleDropDown(element, true)
+      EventHandler.trigger(element, EVENT_SHOWN, {
+        relatedTarget: relatedElem
+      })
     }
+
+    this._queueCallback(complete, element, isAnimated)
   }
 
-  _transitionComplete(element, active, callback) {
-    if (active) {
-      active.classList.remove(CLASS_NAME_ACTIVE)
+  _deactivate(element, relatedElem) {
+    if (!element) {
+      return
+    }
+
+    element.classList.remove(CLASS_NAME_ACTIVE)
+    element.blur()
 
-      const dropdownChild = SelectorEngine.findOne(SELECTOR_DROPDOWN_ACTIVE_CHILD, active.parentNode)
+    this._deactivate(getElementFromSelector(element)) // Search and deactivate the shown section too
 
-      if (dropdownChild) {
-        dropdownChild.classList.remove(CLASS_NAME_ACTIVE)
+    const isAnimated = element.classList.contains(CLASS_NAME_FADE)
+    const complete = () => {
+      if (isAnimated) { // todo maybe is redundant
+        element.classList.remove(CLASS_NAME_SHOW)
       }
 
-      if (active.getAttribute('role') === 'tab') {
-        active.setAttribute('aria-selected', false)
+      if (element.getAttribute('role') !== 'tab') {
+        return
       }
+
+      element.setAttribute('aria-selected', false)
+      element.setAttribute('tabindex', '-1')
+      this._toggleDropDown(element, false)
+      EventHandler.trigger(element, EVENT_HIDDEN, { relatedTarget: relatedElem })
     }
 
-    element.classList.add(CLASS_NAME_ACTIVE)
-    if (element.getAttribute('role') === 'tab') {
-      element.setAttribute('aria-selected', true)
+    this._queueCallback(complete, element, isAnimated)
+  }
+
+  _keydown(event) {
+    if (!([ARROW_LEFT_KEY, ARROW_RIGHT_KEY, ARROW_UP_KEY, ARROW_DOWN_KEY].includes(event.key))) {
+      return
+    }
+
+    event.stopPropagation()// stopPropagation/preventDefault both added to support up/down keys without scrolling the page
+    event.preventDefault()
+    const isNext = [ARROW_RIGHT_KEY, ARROW_DOWN_KEY].includes(event.key)
+    const nextActiveElement = getNextActiveElement(this._getChildren(), event.target, isNext, true)
+    Tab.getOrCreateInstance(nextActiveElement).show()
+  }
+
+  _getChildren() { // collection of inner elements
+    return SelectorEngine.find(SELECTOR_INNER_ELEM, this._parent)
+  }
+
+  _getActiveElem() {
+    return this._getChildren().find(child => this._elemIsActive(child)) || null
+  }
+
+  _setInitialAttributes(parent, children) {
+    this._setAttributeIfNotExists(parent, 'role', 'tablist')
+
+    for (const child of children) {
+      this._setInitialAttributesOnChild(child)
     }
+  }
 
-    reflow(element)
+  _setInitialAttributesOnChild(child) {
+    child = this._getInnerElement(child)
+    const isActive = this._elemIsActive(child)
+    const outerElem = this._getOuterElement(child)
+    child.setAttribute('aria-selected', isActive)
 
-    if (element.classList.contains(CLASS_NAME_FADE)) {
-      element.classList.add(CLASS_NAME_SHOW)
+    if (outerElem !== child) {
+      this._setAttributeIfNotExists(outerElem, 'role', 'presentation')
     }
 
-    let parent = element.parentNode
-    if (parent && parent.nodeName === 'LI') {
-      parent = parent.parentNode
+    if (!isActive) {
+      child.setAttribute('tabindex', '-1')
     }
 
-    if (parent && parent.classList.contains(CLASS_NAME_DROPDOWN_MENU)) {
-      const dropdownElement = element.closest(SELECTOR_DROPDOWN)
+    this._setAttributeIfNotExists(child, 'role', 'tab')
 
-      if (dropdownElement) {
-        for (const dropdown of SelectorEngine.find(SELECTOR_DROPDOWN_TOGGLE, dropdownElement)) {
-          dropdown.classList.add(CLASS_NAME_ACTIVE)
-        }
-      }
+    // set attributes to the related panel too
+    this._setInitialAttributesOnTargetPanel(child)
+  }
+
+  _setInitialAttributesOnTargetPanel(child) {
+    const target = getElementFromSelector(child)
 
-      element.setAttribute('aria-expanded', true)
+    if (!target) {
+      return
     }
 
-    if (callback) {
-      callback()
+    this._setAttributeIfNotExists(target, 'role', 'tabpanel')
+
+    if (child.id) {
+      this._setAttributeIfNotExists(target, 'aria-labelledby', `#${child.id}`)
     }
   }
 
+  _toggleDropDown(element, open) {
+    const outerElem = this._getOuterElement(element)
+    if (!outerElem.classList.contains(CLASS_DROPDOWN)) {
+      return
+    }
+
+    const toggle = (selector, className) => {
+      const element = SelectorEngine.findOne(selector, outerElem)
+      if (element) {
+        element.classList.toggle(className, open)
+      }
+    }
+
+    toggle(SELECTOR_DROPDOWN_TOGGLE, CLASS_NAME_ACTIVE)
+    toggle(SELECTOR_DROPDOWN_MENU, CLASS_NAME_SHOW)
+    toggle(SELECTOR_DROPDOWN_ITEM, CLASS_NAME_ACTIVE)
+    outerElem.setAttribute('aria-expanded', open)
+  }
+
+  _setAttributeIfNotExists(element, attribute, value) {
+    if (!element.hasAttribute(attribute)) {
+      element.setAttribute(attribute, value)
+    }
+  }
+
+  _elemIsActive(elem) {
+    return elem.classList.contains(CLASS_NAME_ACTIVE)
+  }
+
+  // Try to get the inner element (usually the .nav-link)
+  _getInnerElement(elem) {
+    return elem.matches(SELECTOR_INNER_ELEM) ? elem : SelectorEngine.findOne(SELECTOR_INNER_ELEM, elem)
+  }
+
+  // Try to get the outer element (usually the .nav-item)
+  _getOuterElement(elem) {
+    return elem.closest(SELECTOR_OUTER) || elem
+  }
+
   // Static
   static jQueryInterface(config) {
     return this.each(function () {
       const data = Tab.getOrCreateInstance(this)
 
-      if (typeof config === 'string') {
-        if (typeof data[config] === 'undefined') {
-          throw new TypeError(`No method named "${config}"`)
-        }
+      if (typeof config !== 'string') {
+        return
+      }
 
-        data[config]()
+      if (data[config] === undefined || config.startsWith('_') || config === 'constructor') {
+        throw new TypeError(`No method named "${config}"`)
       }
+
+      data[config]()
     })
   }
 }
@@ -186,11 +292,18 @@ EventHandler.on(document, EVENT_CLICK_DATA_API, SELECTOR_DATA_TOGGLE, function (
     return
   }
 
-  const data = Tab.getOrCreateInstance(this)
-  data.show()
+  Tab.getOrCreateInstance(this).show()
 })
 
 /**
+ * Initialize on focus
+ */
+EventHandler.on(window, EVENT_LOAD_DATA_API, () => {
+  for (const element of SelectorEngine.find(SELECTOR_DATA_TOGGLE_ACTIVE)) {
+    Tab.getOrCreateInstance(element)
+  }
+})
+/**
  * jQuery
  */
 
diff --git a/js/tests/unit/tab.spec.js b/js/tests/unit/tab.spec.js
index a0fb89bd47..4b8fb62de6 100644
--- a/js/tests/unit/tab.spec.js
+++ b/js/tests/unit/tab.spec.js
@@ -1,5 +1,5 @@
 import Tab from '../../src/tab'
-import { clearFixture, getFixture, jQueryMock } from '../helpers/fixture'
+import { clearFixture, createEvent, getFixture, jQueryMock } from '../helpers/fixture'
 
 describe('Tab', () => {
   let fixtureEl
@@ -38,6 +38,19 @@ describe('Tab', () => {
     })
   })
 
+  describe('constructor', () => {
+    it('Do not Throw exception if not parent', () => {
+      fixtureEl.innerHTML = [
+        fixtureEl.innerHTML = '<div class=""><div class="nav-link"></div></div>'
+      ].join('')
+      const navEl = fixtureEl.querySelector('.nav-link')
+
+      expect(() => {
+        new Tab(navEl) // eslint-disable-line no-new
+      }).not.toThrowError(TypeError)
+    })
+  })
+
   describe('show', () => {
     it('should activate element by tab id (using buttons, the preferred semantic way)', () => {
       return new Promise(resolve => {
@@ -168,9 +181,9 @@ describe('Tab', () => {
 
     it('should not fire shown when show is prevented', () => {
       return new Promise((resolve, reject) => {
-        fixtureEl.innerHTML = '<div class="nav"></div>'
+        fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-        const navEl = fixtureEl.querySelector('div')
+        const navEl = fixtureEl.querySelector('.nav > div')
         const tab = new Tab(navEl)
         const expectDone = () => {
           setTimeout(() => {
@@ -256,7 +269,7 @@ describe('Tab', () => {
         fixtureEl.innerHTML = [
           '<ul class="nav" role="tablist">',
           '  <li><button type="button" data-bs-target="#home" role="tab">Home</button></li>',
-          '  <li><button type="button" data-bs-target="#profile">Profile</button></li>',
+          '  <li><button type="button" data-bs-target="#profile" role="tab">Profile</button></li>',
           '</ul>'
         ].join('')
 
@@ -374,10 +387,10 @@ describe('Tab', () => {
 
   describe('dispose', () => {
     it('should dispose a tab', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-      const el = fixtureEl.querySelector('div')
-      const tab = new Tab(fixtureEl.querySelector('div'))
+      const el = fixtureEl.querySelector('.nav > div')
+      const tab = new Tab(fixtureEl.querySelector('.nav > div'))
 
       expect(Tab.getInstance(el)).not.toBeNull()
 
@@ -387,11 +400,161 @@ describe('Tab', () => {
     })
   })
 
+  describe('_activate', () => {
+    it('should not be called if element argument is null', () => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav" role="tablist">',
+        '  <li class="nav-link"></li>',
+        '</ul>'
+      ].join('')
+
+      const tabEl = fixtureEl.querySelector('.nav-link')
+      const tab = new Tab(tabEl)
+      const spy = jasmine.createSpy('spy')
+
+      spyOn(tab, '_queueCallback')
+      tab._activate(null, spy)
+      expect(tab._queueCallback).not.toHaveBeenCalled()
+      expect(spy).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('_setInitialAttributes', () => {
+    it('should put aria attributes', () => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav">',
+        '  <li class="nav-link" id="foo" data-bs-target="#panel"></li>',
+        '  <li class="nav-link" data-bs-target="#panel2"></li>',
+        '</ul>',
+        '<div id="panel"></div>',
+        '<div id="panel2"></div>'
+      ].join('')
+
+      const tabEl = fixtureEl.querySelector('.nav-link')
+      const parent = fixtureEl.querySelector('.nav')
+      const children = fixtureEl.querySelectorAll('.nav-link')
+      const tabPanel = fixtureEl.querySelector('#panel')
+      const tabPanel2 = fixtureEl.querySelector('#panel2')
+
+      expect(parent.getAttribute('role')).toEqual(null)
+      expect(tabEl.getAttribute('role')).toEqual(null)
+      expect(tabPanel.getAttribute('role')).toEqual(null)
+      const tab = new Tab(tabEl)
+      tab._setInitialAttributes(parent, children)
+
+      expect(parent.getAttribute('role')).toEqual('tablist')
+      expect(tabEl.getAttribute('role')).toEqual('tab')
+
+      expect(tabPanel.getAttribute('role')).toEqual('tabpanel')
+      expect(tabPanel2.getAttribute('role')).toEqual('tabpanel')
+      expect(tabPanel.hasAttribute('tabindex')).toBeFalse()
+      expect(tabPanel.hasAttribute('tabindex2')).toBeFalse()
+
+      expect(tabPanel.getAttribute('aria-labelledby')).toEqual('#foo')
+      expect(tabPanel2.hasAttribute('aria-labelledby')).toBeFalse()
+    })
+  })
+
+  describe('_keydown', () => {
+    it('if event is not one of left/right/up/down arrow, ignore it', () => {
+      fixtureEl.innerHTML = [
+        '<ul class="nav">',
+        '  <li class="nav-link" data-bs-toggle="tab"></li>',
+        '</ul>'
+      ].join('')
+
+      const tabEl = fixtureEl.querySelector('.nav-link')
+      const tab = new Tab(tabEl)
+
+      const keydown = createEvent('keydown')
+      keydown.key = 'Enter'
+      spyOn(Event.prototype, 'stopPropagation').and.callThrough()
+      spyOn(Event.prototype, 'preventDefault').and.callThrough()
+      spyOn(tab, '_keydown')
+      spyOn(tab, '_getChildren')
+
+      tabEl.dispatchEvent(keydown)
+      expect(tab._keydown).toHaveBeenCalled()
+      expect(tab._getChildren).not.toHaveBeenCalled()
+
+      expect(Event.prototype.stopPropagation).not.toHaveBeenCalled()
+      expect(Event.prototype.preventDefault).not.toHaveBeenCalled()
+    })
+
+    it('if keydown event is right/down arrow, handle it', () => {
+      fixtureEl.innerHTML = [
+        '<div class="nav">',
+        '  <span id="tab1" class="nav-link" data-bs-toggle="tab"></span>',
+        '  <span id="tab2" class="nav-link" data-bs-toggle="tab"></span>',
+        '</div>'
+      ].join('')
+
+      const tabEl = fixtureEl.querySelector('#tab1')
+      const tabEl2 = fixtureEl.querySelector('#tab2')
+      const tab = new Tab(tabEl)
+      const tab2 = new Tab(tabEl2)
+      spyOn(tab, 'show').and.callThrough()
+      spyOn(tab2, 'show').and.callThrough()
+
+      spyOn(Event.prototype, 'stopPropagation').and.callThrough()
+      spyOn(Event.prototype, 'preventDefault').and.callThrough()
+
+      let keydown = createEvent('keydown')
+      keydown.key = 'ArrowRight'
+
+      tabEl.dispatchEvent(keydown)
+      expect(tab2.show).toHaveBeenCalled()
+
+      keydown = createEvent('keydown')
+      keydown.key = 'ArrowDown'
+
+      tabEl2.dispatchEvent(keydown)
+      expect(tab.show).toHaveBeenCalled()
+
+      expect(Event.prototype.stopPropagation).toHaveBeenCalledTimes(2)
+      expect(Event.prototype.preventDefault).toHaveBeenCalledTimes(2)
+    })
+
+    it('if keydown event is left arrow, handle it', () => {
+      fixtureEl.innerHTML = [
+        '<div class="nav">',
+        '  <span id="tab1" class="nav-link" data-bs-toggle="tab"></span>',
+        '  <span id="tab2" class="nav-link" data-bs-toggle="tab"></span>',
+        '</div>'
+      ].join('')
+
+      const tabEl = fixtureEl.querySelector('#tab1')
+      const tabEl2 = fixtureEl.querySelector('#tab2')
+      const tab = new Tab(tabEl)
+      const tab2 = new Tab(tabEl2)
+      spyOn(tab, 'show').and.callThrough()
+      spyOn(tab2, 'show').and.callThrough()
+
+      spyOn(Event.prototype, 'stopPropagation').and.callThrough()
+      spyOn(Event.prototype, 'preventDefault').and.callThrough()
+
+      let keydown = createEvent('keydown')
+      keydown.key = 'ArrowLeft'
+
+      tabEl2.dispatchEvent(keydown)
+      expect(tab.show).toHaveBeenCalled()
+
+      keydown = createEvent('keydown')
+      keydown.key = 'ArrowUp'
+
+      tabEl.dispatchEvent(keydown)
+      expect(tab2.show).toHaveBeenCalled()
+
+      expect(Event.prototype.stopPropagation).toHaveBeenCalledTimes(2)
+      expect(Event.prototype.preventDefault).toHaveBeenCalledTimes(2)
+    })
+  })
+
   describe('jQueryInterface', () => {
     it('should create a tab', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-      const div = fixtureEl.querySelector('div')
+      const div = fixtureEl.querySelector('.nav > div')
 
       jQueryMock.fn.tab = Tab.jQueryInterface
       jQueryMock.elements = [div]
@@ -402,9 +565,9 @@ describe('Tab', () => {
     })
 
     it('should not re create a tab', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-      const div = fixtureEl.querySelector('div')
+      const div = fixtureEl.querySelector('.nav > div')
       const tab = new Tab(div)
 
       jQueryMock.fn.tab = Tab.jQueryInterface
@@ -416,9 +579,9 @@ describe('Tab', () => {
     })
 
     it('should call a tab method', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-      const div = fixtureEl.querySelector('div')
+      const div = fixtureEl.querySelector('.nav > div')
       const tab = new Tab(div)
 
       spyOn(tab, 'show')
@@ -433,9 +596,9 @@ describe('Tab', () => {
     })
 
     it('should throw error on undefined method', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-      const div = fixtureEl.querySelector('div')
+      const div = fixtureEl.querySelector('.nav > div')
       const action = 'undefinedMethod'
 
       jQueryMock.fn.tab = Tab.jQueryInterface
@@ -453,9 +616,9 @@ describe('Tab', () => {
     })
 
     it('should return this instance', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
-      const divEl = fixtureEl.querySelector('div')
+      const divEl = fixtureEl.querySelector('.nav > div')
       const tab = new Tab(divEl)
 
       expect(Tab.getInstance(divEl)).toEqual(tab)
@@ -465,7 +628,7 @@ describe('Tab', () => {
 
   describe('getOrCreateInstance', () => {
     it('should return tab instance', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
       const div = fixtureEl.querySelector('div')
       const tab = new Tab(div)
@@ -476,7 +639,7 @@ describe('Tab', () => {
     })
 
     it('should return new instance when there is no tab instance', () => {
-      fixtureEl.innerHTML = '<div></div>'
+      fixtureEl.innerHTML = '<div class="nav"><div class="nav-link"></div></div>'
 
       const div = fixtureEl.querySelector('div')
 
@@ -651,11 +814,8 @@ describe('Tab', () => {
         const tabProfileEl = fixtureEl.querySelector('#profile')
         const tabHomeEl = fixtureEl.querySelector('#home')
 
-        triggerTabProfileEl.addEventListener('shown.bs.tab', () => {
-          expect(tabProfileEl).toHaveClass('fade')
-          expect(tabProfileEl).toHaveClass('show')
-
-          triggerTabHomeEl.addEventListener('shown.bs.tab', () => {
+        triggerTabHomeEl.addEventListener('shown.bs.tab', () => {
+          setTimeout(() => {
             expect(tabProfileEl).toHaveClass('fade')
             expect(tabProfileEl).not.toHaveClass('show')
 
@@ -663,16 +823,22 @@ describe('Tab', () => {
             expect(tabHomeEl).toHaveClass('show')
 
             resolve()
-          })
+          }, 10)
+        })
 
-          triggerTabHomeEl.click()
+        triggerTabProfileEl.addEventListener('shown.bs.tab', () => {
+          setTimeout(() => {
+            expect(tabProfileEl).toHaveClass('fade')
+            expect(tabProfileEl).toHaveClass('show')
+            triggerTabHomeEl.click()
+          }, 10)
         })
 
         triggerTabProfileEl.click()
       })
     })
 
-    it('should not add show class to tab panes if there is no `.fade` class', () => {
+    it('should not add `show` class to tab panes if there is no `.fade` class', () => {
       return new Promise(resolve => {
         fixtureEl.innerHTML = [
           '<ul class="nav nav-tabs" role="tablist">',
@@ -720,8 +886,10 @@ describe('Tab', () => {
         const secondNavEl = fixtureEl.querySelector('#secondNav')
 
         secondNavEl.addEventListener('shown.bs.tab', () => {
-          expect(fixtureEl.querySelectorAll('.show')).toHaveSize(1)
-          resolve()
+          setTimeout(() => {
+            expect(fixtureEl.querySelectorAll('.show')).toHaveSize(1)
+            resolve()
+          }, 10)
         })
 
         secondNavEl.click()