Fix #14 - Explicitly find the selected index

Author: WebReflection

cjs/utils.js

@@ -1,18 +1,22 @@
 'use strict';
 const Map = (require('@ungap/essential-map'));
 
+const {indexOf: iOF} = [];
 const append = (get, parent, children, start, end, before) => {
   const isSelect = 'selectedIndex' in parent;
-  let selectedIndex = -1;
+  let noSelection = isSelect;
   while (start < end) {
     const child = get(children[start], 1);
-    if (isSelect && selectedIndex < 0 && child.selected)
-      selectedIndex = start;
     parent.insertBefore(child, before);
+    if (isSelect && noSelection && child.selected) {
+      noSelection = !noSelection;
+      let {selectedIndex} = parent;
+      parent.selectedIndex = selectedIndex < 0 ?
+        start :
+        iOF.call(parent.querySelectorAll('option'), child);
+    }
     start++;
   }
-  if (isSelect && -1 < selectedIndex)
-    parent.selectedIndex = selectedIndex;
 };
 exports.append = append;
 

esm/utils.js

@@ -1,17 +1,21 @@
 import Map from '@ungap/essential-map';
 
+const {indexOf: iOF} = [];
 export const append = (get, parent, children, start, end, before) => {
   const isSelect = 'selectedIndex' in parent;
-  let selectedIndex = -1;
+  let noSelection = isSelect;
   while (start < end) {
     const child = get(children[start], 1);
-    if (isSelect && selectedIndex < 0 && child.selected)
-      selectedIndex = start;
     parent.insertBefore(child, before);
+    if (isSelect && noSelection && child.selected) {
+      noSelection = !noSelection;
+      let {selectedIndex} = parent;
+      parent.selectedIndex = selectedIndex < 0 ?
+        start :
+        iOF.call(parent.querySelectorAll('option'), child);
+    }
     start++;
   }
-  if (isSelect && -1 < selectedIndex)
-    parent.selectedIndex = selectedIndex;
 };
 
 export const eqeq = (a, b) => a == b;

index.js

@@ -43,16 +43,22 @@ try {
 }
 var Map$1 = self.Map;
 
+var iOF = [].indexOf;
+
 var append = function append(get, parent, children, start, end, before) {
   var isSelect = 'selectedIndex' in parent;
-  var selectedIndex = -1;
+  var noSelection = isSelect;
   while (start < end) {
     var child = get(children[start], 1);
-    if (isSelect && selectedIndex < 0 && child.selected) selectedIndex = start;
     parent.insertBefore(child, before);
+    if (isSelect && noSelection && child.selected) {
+      noSelection = !noSelection;
+      var selectedIndex = parent.selectedIndex;
+
+      parent.selectedIndex = selectedIndex < 0 ? start : iOF.call(parent.querySelectorAll('option'), child);
+    }
     start++;
   }
-  if (isSelect && -1 < selectedIndex) parent.selectedIndex = selectedIndex;
 };
 
 var eqeq = function eqeq(a, b) {

min.js

@@ -1236,8 +1236,36 @@ newState = domdiff(
     document.createTextNode('c')
   ]
 );
-
 console.assert(document.body.selectedIndex === 1, 'selectedIndex is OK');
+
+newState = domdiff(
+  document.body,
+  newState,
+  []
+);
+document.body.selectedIndex = 0;
+document.body.querySelectorAll = _ => newState.concat(newOptions);
+option = document.createTextNode('option');
+option.selected = true;
+newState = domdiff(
+  document.body,
+  newState,
+  [
+    document.createTextNode('option')
+  ]
+);
+var newOptions = [
+  document.createTextNode('option'),
+  option,
+  document.createTextNode('option')
+];
+newState = domdiff(
+  document.body,
+  newState,
+  newOptions
+);
+console.assert(document.body.selectedIndex === 2, 'partial selectedIndex is OK');
+
 // */
 
 tressa.end();