Tiling? Tint coverage?

Nodemon should be a devDependency not a dependency.
Also, I think you may have a few extra dev dependencies which may not be needed

Sometimes your autocomplete offers the same word multiple times

QUnit.test( "test displayOptionsList", function( assert ) {
  document.getElementsByTagName("input")[0].value = "";
  wordFinder.displayOptionsList();
  assert.equal(document.getElementById("results").style.display, "none", "sets display to none" );
});

Perhaps at the start of this test create a variable that stores the initial display style of the input element (visible/block), then after the wordFinder.displayOptionsList function make another variable that holds the new display style, then compare the two in the test

At [autocomplete/public/test/test.html] all your tests are passing... but there aren't any tests.

When you delete this function is seems to have no effect on the application.

E.g you'll get suggestions when typing 'he' but if you type 'he\' they stop.

The server strips all non-alphanumeric characters before searching for words and if you look at network activity in dev tools you can see that it's correctly sending back responses that are valid for the input with the non-alphanumeric characters stripped out.

So possibly this is a bug in the Chrome implementation of datalist but I'm not sure how to investigate further.

Your server.js file requires the handler.js file which deals with the routes and logic of the server.
It may be cleared to separate the handler file into a routes file (which contains logic to handle endpoints), and have that require separate handlers. Currently this is not too much of an issue currently as the application has few endpoints, but having a single handler file in the future could be confusing to navigate through

If you have more than one/two files of a certain type it would be good to think about putting them in designated folders.

eg. all the front-end js files to go in public/js and css in public/(styles or css)

So that the server handles the text being inputted into the form.

The options bar doesn't disappear when you empty the search field after having typed in it before.

I like that there are hover states for selecting a word, it would be good to see the input field update when a user selects it, and the suggestions box clear

I think you need a 404-handler

• Codecov

Sorry if this sounds a little petty, but you should include installing the dependencies npm i in the setup instructions

At the moment you are testing the string that gets returned out of the handler function in src/handler.js

I don't think this is a good practice.

I would say a better test would be to test what data the response.end(data) is called on

Something like:

tape('handler', function (t) {
  handler({ url: '/' }, {
  writeHead: function (status, obj) { 
    t.equal(status, 200);
    t.equal(obj, ...);
  },
  end: function (data) {
    t.equal(data, ...);
  }
}
}

I'm not sure if that will work, but something similar to that

function validateInput(query) {
  return query.replace(/[^a-z]/gi, '');
}

function makeRegExp(input) {
  return new RegExp('^' + input, 'i');
}

function match(list, regex) {
  return list.filter(function(word) { return regex.test(word); });
}

These are great! :) We used methods like these throughout our project but didn't think to wrap them in functions, nice :)
Perhaps put these into a 'helpers.js' file and require it in to files that need it?

I know it's only codecov, but this shouldn't be up there

function handlerForSearch (request, response) {
  var searchTerm = request.url.split('?q=')[1];
  response.writeHead(200, {'content-type': 'text/plain'});
  response.end(JSON.stringify(runSmartMatch.smartMatch(searchTerm).slice(0, 10)));
}

Incase there are any issues of the formatting of queries that are passed into this function, use a module like 'url', where you can use .parse methods to access different segments of the url (an object for query holds key and value pairs for the query).
You could then easily have a few checks to see if query formatting is correct and provide a fail case if not