Remove for-of and spread operator use in arrays to prevent Closure from including / using an iterator polyfill.

Author: bicknellr

src/CustomElementInternals.js

@@ -164,7 +164,9 @@ export default class CustomElementInternals {
     element[CustomElementInternalSymbols.definition] = definition;
 
     if (definition.attributeChangedCallback) {
-      for (const name of definition.observedAttributes) {
+      const observedAttributes = definition.observedAttributes;
+      for (let i = 0; i < observedAttributes.length; i++) {
+        const name = observedAttributes[i];
         const value = element.getAttribute(name);
         if (value !== null) {
           this.attributeChangedCallback(element, name, null, value, null);

src/DocumentConstructionObserver.js

@@ -48,9 +48,10 @@ export default class DocumentConstructionObserver {
       this._observer.disconnect();
     }
 
-    for (const mutation of mutations) {
-      for (const addedNode of mutation.addedNodes) {
-        this._internals.upgradeTree(addedNode);
+    for (let i = 0; i < mutations.length; i++) {
+      const addedNodes = mutations[i].addedNodes;
+      for (let j = 0; j < addedNodes.length; j++) {
+        this._internals.upgradeTree(addedNodes[j]);
       }
     }
   }

src/Patch/Interface/ChildNode.js

@@ -28,12 +28,13 @@ export default function(internals, destination, builtIn) {
 
     builtIn.before.apply(this, nodes);
 
-    for (const node of connectedBefore) {
-      internals.disconnectTree(node);
+    for (let i = 0; i < connectedBefore.length; i++) {
+      internals.disconnectTree(connectedBefore[i]);
     }
 
     if (Utilities.isConnected(this)) {
-      for (const node of nodes) {
+      for (let i = 0; i < nodes.length; i++) {
+        const node = nodes[i];
         if (node instanceof Element) {
           internals.connectTree(node);
         }
@@ -52,12 +53,13 @@ export default function(internals, destination, builtIn) {
 
     builtIn.after.apply(this, nodes);
 
-    for (const node of connectedBefore) {
-      internals.disconnectTree(node);
+    for (let i = 0; i < connectedBefore.length; i++) {
+      internals.disconnectTree(connectedBefore[i]);
     }
 
     if (Utilities.isConnected(this)) {
-      for (const node of nodes) {
+      for (let i = 0; i < nodes.length; i++) {
+        const node = nodes[i];
         if (node instanceof Element) {
           internals.connectTree(node);
         }
@@ -78,13 +80,14 @@ export default function(internals, destination, builtIn) {
 
     builtIn.replaceWith.apply(this, nodes);
 
-    for (const node of connectedBefore) {
-      internals.disconnectTree(node);
+    for (let i = 0; i < connectedBefore.length; i++) {
+      internals.disconnectTree(connectedBefore[i]);
     }
 
     if (wasConnected) {
       internals.disconnectTree(this);
-      for (const node of nodes) {
+      for (let i = 0; i < nodes.length; i++) {
+        const node = nodes[i];
         if (node instanceof Element) {
           internals.connectTree(node);
         }

src/Patch/Interface/ParentNode.js

@@ -26,12 +26,13 @@ export default function(internals, destination, builtIn) {
 
     builtIn.prepend.apply(this, nodes);
 
-    for (const node of connectedBefore) {
-      internals.disconnectTree(node);
+    for (let i = 0; i < connectedBefore.length; i++) {
+      internals.disconnectTree(connectedBefore[i]);
     }
 
     if (Utilities.isConnected(this)) {
-      for (const node of nodes) {
+      for (let i = 0; i < nodes.length; i++) {
+        const node = nodes[i];
         if (node instanceof Element) {
           internals.connectTree(node);
         }
@@ -50,12 +51,13 @@ export default function(internals, destination, builtIn) {
 
     builtIn.append.apply(this, nodes);
 
-    for (const node of connectedBefore) {
-      internals.disconnectTree(node);
+    for (let i = 0; i < connectedBefore.length; i++) {
+      internals.disconnectTree(connectedBefore[i]);
     }
 
     if (Utilities.isConnected(this)) {
-      for (const node of nodes) {
+      for (let i = 0; i < nodes.length; i++) {
+        const node = nodes[i];
         if (node instanceof Element) {
           internals.connectTree(node);
         }

src/Patch/Node.js

@@ -20,15 +20,15 @@ export default function(internals) {
    */
   Node.prototype.insertBefore = function(node, refNode) {
     if (node instanceof DocumentFragment) {
-      const insertedNodes = [...node.childNodes];
+      const insertedNodes = Array.prototype.slice.apply(node.childNodes);
       const nativeResult = BuiltIn.Node_insertBefore.call(this, node, refNode);
 
       // DocumentFragments can't be connected, so `disconnectTree` will never
       // need to be called on a DocumentFragment's children after inserting it.
 
       if (Utilities.isConnected(this)) {
-        for (const node of insertedNodes) {
-          internals.connectTree(node);
+        for (let i = 0; i < insertedNodes.length; i++) {
+          internals.connectTree(insertedNodes[i]);
         }
       }
 
@@ -56,15 +56,15 @@ export default function(internals) {
    */
   Node.prototype.appendChild = function(node) {
     if (node instanceof DocumentFragment) {
-      const insertedNodes = [...node.childNodes];
+      const insertedNodes = Array.prototype.slice.apply(node.childNodes);
       const nativeResult = BuiltIn.Node_appendChild.call(this, node);
 
       // DocumentFragments can't be connected, so `disconnectTree` will never
       // need to be called on a DocumentFragment's children after inserting it.
 
       if (Utilities.isConnected(this)) {
-        for (const node of insertedNodes) {
-          internals.connectTree(node);
+        for (let i = 0; i < insertedNodes.length; i++) {
+          internals.connectTree(insertedNodes[i]);
         }
       }
 
@@ -120,16 +120,16 @@ export default function(internals) {
    */
   Node.prototype.replaceChild = function(nodeToInsert, nodeToRemove) {
     if (nodeToInsert instanceof DocumentFragment) {
-      const insertedNodes = [...nodeToInsert.childNodes];
+      const insertedNodes = Array.prototype.slice.apply(nodeToInsert.childNodes);
       const nativeResult = BuiltIn.Node_replaceChild.call(this, nodeToInsert, nodeToRemove);
 
       // DocumentFragments can't be connected, so `disconnectTree` will never
       // need to be called on a DocumentFragment's children after inserting it.
 
       if (Utilities.isConnected(this)) {
         internals.disconnectTree(nodeToRemove);
-        for (const node of insertedNodes) {
-          internals.connectTree(node);
+        for (let i = 0; i < insertedNodes.length; i++) {
+          internals.connectTree(insertedNodes[i]);
         }
       }