The current implementation is equivalent to String#startsWith. We don't have any plans to change this in v1, but it is on our things to consider for future versions.

@CMTegner - i see the line right here:
https://github.com/reactjs/react-autocomplete/blob/master/lib/Autocomplete.js#L352

 const itemValueDoesMatch = (itemValue.toLowerCase().indexOf(
        value.toLowerCase()
      ) === 0)

Why is it difficult to change it to something like:

 const itemValueDoesMatch = (itemValue.toLowerCase().includes(
        value.toLowerCase()))

It's not difficult, we just don't intend on changing the behaviour at the moment. When we eventually do, we will want to create something that is flexible enough to cater to different needs, and not just a single use case.

@CMTegner - I've forked the repo, added a predicate support, which is essentially a function receiving itemValue: String and inputValue: String and should return a boolean result,
You can see it here:
master...madlandev:master

It's not possible for me to create a fork since I've included the build files for our own modules, but should you desire, I can create one for you guys.

@silicakes Would you be interested in submitting a PR with your changes to implement this? It seems like it should be expected functionality.

I've found a "solution" for my use case, I just want it to select the first in the list by default, so that the user can hit enter and it will select the first in the list, for the getItemValue(item) just return the input query, that way the first always matches the default match and is selected until the user starts navigating with the arrow keys.
It's not pretty but it works for my use case :)