Switch to strings constants.

This allows the minifier to mangle the constants. It also allows the linter to find unused strings properly.

While at it, remove a few unused properties.

File                        Before      After       Diff
--------------------------------------------------------
bootstrap.bundle.min.js     23.61 kB    22.61 kB    -1.00 kB (-4.23 %)
bootstrap.min.js            17.04 kB    16.08 kB    -0.96 kB (-5.63 %)

1 files changed, 42 insertions, 48 deletions

diff --git a/js/src/tab.js b/js/src/tab.js
index d9bd1fc05..f7ec29946 100644
--- a/js/src/tab.js
+++ b/js/src/tab.js
@@ -30,31 +30,25 @@ 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'
-}
+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 CLASS_NAME_DROPDOWN_MENU = 'dropdown-menu'
+const CLASS_NAME_ACTIVE = 'active'
+const CLASS_NAME_DISABLED = 'disabled'
+const CLASS_NAME_FADE = 'fade'
+const CLASS_NAME_SHOW = 'show'
+
+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-toggle="tab"], [data-toggle="pill"], [data-toggle="list"]'
+const SELECTOR_DROPDOWN_TOGGLE = '.dropdown-toggle'
+const SELECTOR_DROPDOWN_ACTIVE_CHILD = ':scope > .dropdown-menu .active'
 
 /**
  * ------------------------------------------------------------------------
@@ -80,17 +74,17 @@ class Tab {
   show() {
     if ((this._element.parentNode &&
       this._element.parentNode.nodeType === Node.ELEMENT_NODE &&
-      this._element.classList.contains(ClassName.ACTIVE)) ||
-      this._element.classList.contains(ClassName.DISABLED)) {
+      this._element.classList.contains(CLASS_NAME_ACTIVE)) ||
+      this._element.classList.contains(CLASS_NAME_DISABLED)) {
       return
     }
 
     let previous
     const target = getElementFromSelector(this._element)
-    const listElement = SelectorEngine.closest(this._element, Selector.NAV_LIST_GROUP)
+    const listElement = SelectorEngine.closest(this._element, SELECTOR_NAV_LIST_GROUP)
 
     if (listElement) {
-      const itemSelector = listElement.nodeName === 'UL' || listElement.nodeName === 'OL' ? Selector.ACTIVE_UL : Selector.ACTIVE
+      const itemSelector = listElement.nodeName === 'UL' || listElement.nodeName === 'OL' ? SELECTOR_ACTIVE_UL : SELECTOR_ACTIVE
       previous = makeArray(SelectorEngine.find(itemSelector, listElement))
       previous = previous[previous.length - 1]
     }
@@ -98,12 +92,12 @@ class Tab {
     let hideEvent = null
 
     if (previous) {
-      hideEvent = EventHandler.trigger(previous, Event.HIDE, {
+      hideEvent = EventHandler.trigger(previous, EVENT_HIDE, {
         relatedTarget: this._element
       })
     }
 
-    const showEvent = EventHandler.trigger(this._element, Event.SHOW, {
+    const showEvent = EventHandler.trigger(this._element, EVENT_SHOW, {
       relatedTarget: previous
     })
 
@@ -118,10 +112,10 @@ class Tab {
     )
 
     const complete = () => {
-      EventHandler.trigger(previous, Event.HIDDEN, {
+      EventHandler.trigger(previous, EVENT_HIDDEN, {
         relatedTarget: this._element
       })
-      EventHandler.trigger(this._element, Event.SHOWN, {
+      EventHandler.trigger(this._element, EVENT_SHOWN, {
         relatedTarget: previous
       })
     }
@@ -142,12 +136,12 @@ class Tab {
 
   _activate(element, container, callback) {
     const activeElements = container && (container.nodeName === 'UL' || container.nodeName === 'OL') ?
-      SelectorEngine.find(Selector.ACTIVE_UL, container) :
-      SelectorEngine.children(container, Selector.ACTIVE)
+      SelectorEngine.find(SELECTOR_ACTIVE_UL, container) :
+      SelectorEngine.children(container, SELECTOR_ACTIVE)
 
     const active = activeElements[0]
     const isTransitioning = callback &&
-      (active && active.classList.contains(ClassName.FADE))
+      (active && active.classList.contains(CLASS_NAME_FADE))
 
     const complete = () => this._transitionComplete(
       element,
@@ -157,7 +151,7 @@ class Tab {
 
     if (active && isTransitioning) {
       const transitionDuration = getTransitionDurationFromElement(active)
-      active.classList.remove(ClassName.SHOW)
+      active.classList.remove(CLASS_NAME_SHOW)
 
       EventHandler.one(active, TRANSITION_END, complete)
       emulateTransitionEnd(active, transitionDuration)
@@ -168,12 +162,12 @@ class Tab {
 
   _transitionComplete(element, active, callback) {
     if (active) {
-      active.classList.remove(ClassName.ACTIVE)
+      active.classList.remove(CLASS_NAME_ACTIVE)
 
-      const dropdownChild = SelectorEngine.findOne(Selector.DROPDOWN_ACTIVE_CHILD, active.parentNode)
+      const dropdownChild = SelectorEngine.findOne(SELECTOR_DROPDOWN_ACTIVE_CHILD, active.parentNode)
 
       if (dropdownChild) {
-        dropdownChild.classList.remove(ClassName.ACTIVE)
+        dropdownChild.classList.remove(CLASS_NAME_ACTIVE)
       }
 
       if (active.getAttribute('role') === 'tab') {
@@ -181,23 +175,23 @@ class Tab {
       }
     }
 
-    element.classList.add(ClassName.ACTIVE)
+    element.classList.add(CLASS_NAME_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.classList.contains(CLASS_NAME_FADE)) {
+      element.classList.add(CLASS_NAME_SHOW)
     }
 
-    if (element.parentNode && element.parentNode.classList.contains(ClassName.DROPDOWN_MENU)) {
-      const dropdownElement = SelectorEngine.closest(element, Selector.DROPDOWN)
+    if (element.parentNode && element.parentNode.classList.contains(CLASS_NAME_DROPDOWN_MENU)) {
+      const dropdownElement = SelectorEngine.closest(element, SELECTOR_DROPDOWN)
 
       if (dropdownElement) {
-        makeArray(SelectorEngine.find(Selector.DROPDOWN_TOGGLE))
-          .forEach(dropdown => dropdown.classList.add(ClassName.ACTIVE))
+        makeArray(SelectorEngine.find(SELECTOR_DROPDOWN_TOGGLE))
+          .forEach(dropdown => dropdown.classList.add(CLASS_NAME_ACTIVE))
       }
 
       element.setAttribute('aria-expanded', true)
@@ -235,7 +229,7 @@ class Tab {
  * ------------------------------------------------------------------------
  */
 
-EventHandler.on(document, Event.CLICK_DATA_API, Selector.DATA_TOGGLE, function (event) {
+EventHandler.on(document, EVENT_CLICK_DATA_API, SELECTOR_DATA_TOGGLE, function (event) {
   event.preventDefault()
 
   const data = Data.getData(this, DATA_KEY) || new Tab(this)