wordAtCursor.js

let foobar = document.getElementById('foobar');

foobar.addEventListener('keyup', e => {
    let value = e.target.value;
    let typing = _.endsWith(value, ' ');
    let cursor = e.target.selectionStart;

    let addSpace = _.endsWith(value, ' ');
    let words = _.split(value, ' ');
    words = _.map(words, _.trim);
    let size1 = _.size(words);

    words = _.compact(words);
    let size2 = _.size(words);
    if (!typing && size1 !== size2) e.target.value = _.join(words, ' ');

    let word = _.first(words);
    if (cursor > _.size(word)) {
        if (cursor > 0) cursor--;
        let cut = _.truncate(value, {
            length: cursor,
            separator: ' ',
            omission: ''
        });
        let remain = _.trim(_.replace(value, cut, ''));

        word = _.first(_.split(remain, ' '));
        if (!word) word = _.last(words);
    }

    console.log('Caret at: ', e.target.selectionStart, word)
});