Question: Getting the error 

> 
> Property 'includes' does not exist on type 'string[]'
> 
> 
> 

in node\_modules/ng2-breadcrumb/app/components/breadcrumbService.ts
I am trying to implement breadcrumb functionality in an angular2 app.

Answer: 
If you don't want to change to es2016, just use `arr.indexOf(valueToCheck) !== -1`.
You're probably trying to call .includes() on a set rather than an array. Try calling .has() instead