iserror 
Test whether value is error object.
Installation
$ npm install iserrorAPI
const isError = require('iserror');
isError(new Error('Some error'));
// => true
isError({});
// => falseRunning tests
$ npm test
Test whether value is error object.
$ npm install iserrorconst isError = require('iserror');
isError(new Error('Some error'));
// => true
isError({});
// => false$ npm test