Fixing linter errors and securing code

Author: dg-datavisyn

src/plugin.js

@@ -188,13 +188,15 @@ const ErrorBarsPlugin = {
 
     // map error bar to barchart bar via label property
     barchartCoords.forEach((dataset, i) => {
-      var hidden = chart.data.datasets[i]._meta[0].hidden
-      if (hidden) { 
-        return; 
+      if (chart.data.dataset[i]._meta != null && chart.data.dataset[i]._meta.length > 0) {
+        var hidden = chart.data.datasets[i]._meta[0].hidden;
+        if (hidden) {
+          return;
+        }
       }
-      
+
       dataset.forEach((bar) => {
-        
+
 
         let cur = errorBarCoords[i];
         if (!cur) {