fix: prefer filter over slice

Author: pimlie

src/client/updaters/attribute.js

@@ -7,27 +7,31 @@
 export default function updateAttribute({ attribute } = {}, attrs, tag) {
   const vueMetaAttrString = tag.getAttribute(attribute)
   const vueMetaAttrs = vueMetaAttrString ? vueMetaAttrString.split(',') : []
-  const toRemove = [].concat(vueMetaAttrs)
+  const toRemove = Array.from(vueMetaAttrs)
 
+  const keepIndexes = []
   for (const attr in attrs) {
     if (attrs.hasOwnProperty(attr)) {
-      const val = attrs[attr] || ''
-      tag.setAttribute(attr, val)
+      const value = attrs[attr] || ''
+      tag.setAttribute(attr, value)
 
       if (!vueMetaAttrs.includes(attr)) {
         vueMetaAttrs.push(attr)
       }
 
-      const keepIndex = toRemove.indexOf(attr)
-      if (keepIndex !== -1) {
-        toRemove.splice(keepIndex, 1)
-      }
+      // filter below wont ever check -1
+      keepIndexes.push(toRemove.indexOf(attr))
     }
   }
 
-  toRemove.forEach(attr => tag.removeAttribute(attr))
+  const removedAttributesCount = toRemove
+    .filter((el, index) => !keepIndexes.includes(index))
+    .reduce((acc, attr) => {
+      tag.removeAttribute(attr)
+      return acc + 1
+    }, 0)
 
-  if (vueMetaAttrs.length === toRemove.length) {
+  if (vueMetaAttrs.length === removedAttributesCount) {
     tag.removeAttribute(attribute)
   } else {
     tag.setAttribute(attribute, (vueMetaAttrs.sort()).join(','))