Creating autocomplete with Rails and Semantic UI is very easy, and you should not have problem with that. 
Semantic UI includes search library and all you need to do is just to write couple lines of code.

We are using shared examples if we have the same assertions inside one file.

This is how we can do it:

If you want to check how fast is your request, and which version of your request will be more optimized, you should use Benchmark tool.

What if Rbenv is not changing ruby version, even if everything should work for us?

You can use those two commands to make it work again: