drop support for ie 8

packages/splitjs/src/split.js

@@ -1,6 +1,6 @@
 // The programming goals of Split.js are to deliver readable, understandable and
 // maintainable code, while at the same time manually optimizing for tiny minified file size,
-// browser compatibility without additional requirements, graceful fallback (IE8 is supported)
+// browser compatibility without additional requirements
 // and very few assumptions about the user's page layout.
 const global = window
 const { document } = global
@@ -16,10 +16,6 @@ const bGutterSize = '_c'
 const HORIZONTAL = 'horizontal'
 const NOOP = () => false
 
-// Figure out if we're in IE8 or not. IE8 will still render correctly,
-// but will be static instead of draggable.
-const isIE8 = global.attachEvent && !global[addEventListener]
-
 // Helper function determines which prefixes of CSS calc we need.
 // We only need to do this once on startup, when this anonymous function is called.
 //
@@ -92,11 +88,7 @@ const defaultElementStyleFn = (dim, size, gutSize) => {
     const style = {}
 
     if (!isString(size)) {
-        if (!isIE8) {
         style[dim] = `${calc}(${size}% - ${gutSize}px)`
-        } else {
-            style[dim] = `${size}%`
-        }
     } else {
         style[dim] = size
     }
@@ -623,8 +615,6 @@ const Split = (idsOption, options = {}) => {
         // staticly assigning sizes without draggable gutters. Assigns a string
         // to `size`.
         //
-        // IE9 and above
-        if (!isIE8) {
         // Create gutter elements for each pair.
         if (i > 0) {
             const gutterElement = gutter(i, direction, element.element)
@@ -647,7 +637,6 @@ const Split = (idsOption, options = {}) => {
 
             pair.gutter = gutterElement
         }
-        }
 
         setElementSize(
             element.element,
@@ -744,13 +733,6 @@ const Split = (idsOption, options = {}) => {
         })
     }
 
-    if (isIE8) {
-        return {
-            setSizes,
-            destroy,
-        }
-    }
-
     return {
         setSizes,
         getSizes,