npm and error messages

node_modules/core-js/modules/_to-absolute-index.js

@@ -0,0 +1,7 @@
+var toInteger = require('./_to-integer');
+var max = Math.max;
+var min = Math.min;
+module.exports = function (index, length) {
+  index = toInteger(index);
+  return index < 0 ? max(index + length, 0) : min(index, length);
+};