remove some polyfills (#1288)

* remove some polyfills

* use for-of for iteration when possible

packages/slate-react/src/components/content.js

@@ -8,7 +8,6 @@ import logger from 'slate-dev-logger'
 
 import EVENT_HANDLERS from '../constants/event-handlers'
 import Node from './node'
-import findClosestNode from '../utils/find-closest-node'
 import findDOMRange from '../utils/find-dom-range'
 import findRange from '../utils/find-range'
 import scrollToSelection from '../utils/scroll-to-selection'
@@ -210,7 +209,7 @@ class Content extends React.Component {
     const el = target.nodeType === 3 ? target.parentNode : target
     return (
       (el.isContentEditable) &&
-      (el === element || findClosestNode(el, '[data-slate-editor]') === element)
+      (el === element || el.closest('[data-slate-editor]') === element)
     )
   }
 
@@ -269,7 +268,7 @@ class Content extends React.Component {
       handler == 'onDragStart'
     ) {
       const { target } = event
-      const targetEditorNode = findClosestNode(target, '[data-slate-editor]')
+      const targetEditorNode = target.closest('[data-slate-editor]')
       if (targetEditorNode !== this.element) return
     }
 

packages/slate-react/src/components/editor.js

@@ -140,8 +140,7 @@ class Editor extends React.Component {
     let isNew = false
 
     // Check to see if any plugin-related properœties have changed.
-    for (let i = 0; i < PLUGINS_PROPS.length; i++) {
-      const prop = PLUGINS_PROPS[i]
+    for (const prop of PLUGINS_PROPS) {
       if (props[prop] == this.props[prop]) continue
       isNew = true
       break
@@ -377,9 +376,8 @@ function resolvePlugins(props) {
  * Mix in the property types for the event handlers.
  */
 
-for (let i = 0; i < EVENT_HANDLERS.length; i++) {
-  const property = EVENT_HANDLERS[i]
-  Editor.propTypes[property] = Types.func
+for (const prop of EVENT_HANDLERS) {
+  Editor.propTypes[prop] = Types.func
 }
 
 /**

packages/slate-react/src/constants/environment.js

@@ -59,16 +59,14 @@ let OS
 if (browser) {
   const { userAgent } = window.navigator
 
-  for (let i = 0; i < BROWSER_RULES.length; i++) {
-    const [ name, regexp ] = BROWSER_RULES[i]
+  for (const [ name, regexp ] of BROWSER_RULES) {
     if (regexp.test(userAgent)) {
       BROWSER = name
       break
     }
   }
 
-  for (let i = 0; i < OS_RULES.length; i++) {
-    const [ name, regexp ] = OS_RULES[i]
+  for (const [ name, regexp ] of OS_RULES) {
     if (regexp.test(userAgent)) {
       OS = name
       break
@@ -78,8 +76,7 @@ if (browser) {
   const testEl = window.document.createElement('div')
   testEl.contentEditable = true
 
-  for (let i = 0; i < EVENT_RULES.length; i++) {
-    const [ name, testFn ] = EVENT_RULES[i]
+  for (const [ name, testFn ] of EVENT_RULES) {
     EVENTS[name] = testFn(testEl)
   }
 }

packages/slate-react/src/utils/find-closest-node.js

@@ -1,37 +0,0 @@
-
-/**
- * Find the closest ancestor of a DOM `element` that matches a given selector.
- *
- * COMPAT: In IE11, the `Node.closest` method doesn't exist natively, so we
- * have to polyfill it. (2017/09/06)
- *
- * https://developer.mozilla.org/en-US/docs/Web/API/Element/closest#Polyfill
- *
- * @param {Element} node
- * @param {String} selector
- * @return {Element}
- */
-
-function findClosestNode(node, selector) {
-  if (typeof node.closest === 'function') return node.closest(selector)
-
-  const matches = (node.document || node.ownerDocument).querySelectorAll(selector)
-  let parentNode = node
-  let i
-
-  do {
-    i = matches.length
-    while (--i >= 0 && matches.item(i) !== parentNode);
-  }
-  while ((i < 0) && (parentNode = parentNode.parentElement))
-
-  return parentNode
-}
-
-/**
- * Export.
- *
- * @type {Function}
- */
-
-export default findClosestNode

packages/slate-react/src/utils/find-node.js

@@ -1,6 +1,4 @@
 
-import findClosestNode from './find-closest-node'
-
 /**
  * Find a Slate node from a DOM `element`.
  *
@@ -9,7 +7,7 @@ import findClosestNode from './find-closest-node'
  */
 
 function findNode(element, state) {
-  const closest = findClosestNode(element, '[data-key]')
+  const closest = element.closest('[data-key]')
   if (!closest) return null
 
   const key = closest.getAttribute('data-key')

packages/slate-react/src/utils/find-point.js

@@ -2,7 +2,6 @@
 import getWindow from 'get-window'
 
 import OffsetKey from './offset-key'
-import findClosestNode from './find-closest-node'
 
 /**
  * Constants.
@@ -32,7 +31,7 @@ function findPoint(nativeNode, nativeOffset, state) {
 
   const window = getWindow(nativeNode)
   const { parentNode } = nearestNode
-  let rangeNode = findClosestNode(parentNode, RANGE_SELECTOR)
+  let rangeNode = parentNode.closest(RANGE_SELECTOR)
   let offset
   let node
 
@@ -40,7 +39,7 @@ function findPoint(nativeNode, nativeOffset, state) {
   // determine what the offset relative to the text node is.
   if (rangeNode) {
     const range = window.document.createRange()
-    const textNode = findClosestNode(rangeNode, TEXT_SELECTOR)
+    const textNode = rangeNode.closest(TEXT_SELECTOR)
     range.setStart(textNode, 0)
     range.setEnd(nearestNode, nearestOffset)
     node = textNode
@@ -50,7 +49,7 @@ function findPoint(nativeNode, nativeOffset, state) {
   // For void nodes, the element with the offset key will be a cousin, not an
   // ancestor, so find it by going down from the nearest void parent.
   else {
-    const voidNode = findClosestNode(parentNode, VOID_SELECTOR)
+    const voidNode = parentNode.closest(VOID_SELECTOR)
     if (!voidNode) return null
     rangeNode = voidNode.querySelector(RANGE_SELECTOR)
     node = rangeNode