Merge pull request #313 from feliciousx-open-source/dataset-safari-fix

fix(dataset): check if property exist before deleting

src/modules/dataset.ts

@@ -20,7 +20,9 @@ function updateDataset(oldVnode: VNode, vnode: VNode): void {
   for (key in oldDataset) {
     if (!dataset[key]) {
       if (d) {
-        delete d[key];
+        if (key in d) {
+          delete d[key];
+        }
       } else {
         elm.removeAttribute('data-' + key.replace(CAPS_REGEX, '-$&').toLowerCase());
       }
@@ -38,4 +40,4 @@ function updateDataset(oldVnode: VNode, vnode: VNode): void {
 }
 
 export const datasetModule = {create: updateDataset, update: updateDataset} as Module;
-export default datasetModule;
+export default datasetModule;