Readability score

ari.js

(()=>{
    var CHARACTER_WEIGHT = 4.71;
    var SENTENCE_WEIGHT = 0.5;
    var BASE = 21.43;

    function automatedReadability(counts) {
        if (!counts || !counts.sentence || !counts.word || !counts.character) {
            return NaN;
        }

        //flesch-kincaid
        // return (206.835 - (1.015 * (counts.word / counts.sentence))) - (84.6 * (counts.syllables / counts.words));

        // ARI
        return (CHARACTER_WEIGHT * (counts.character / counts.word)) + (SENTENCE_WEIGHT * (counts.word / counts.sentence)) - BASE;
    }

//     const ari = Math.round(automatedReadability({
//         sentence: 3,
//         word: 69,
//         character: 683
//     }));
    
    const ari = Math.round(automatedReadability({
        sentence: 11,
        word: 275,
        character: 1348
    }));

    const vals = {
        90: 'Very Easy',
        80: 'Easy',
        70: 'Fairly Easy',
        60: 'Standard',
        50: 'Fairly Difficult',
        30: 'Difficult',
        0: 'Very Confusing',
    };

    const valKeys = Object.keys(vals);
    let currentDiff, smallestDiff = Math.abs(ari - valKeys[0]), closest = 0;

    for (let i = 0; i < valKeys.length; i++) {
        currentDiff = Math.abs(ari - valKeys[i]);
        if (currentDiff < smallestDiff) {
            smallestDiff = currentDiff;
            closest = i;
        }
    }

    return vals[valKeys[closest]];
}
)();

contentCount.js

(() => {
    const data = {};
    
    const content = 'Cat ipsum dolor sit amet, cereal boxes make for five star accommodation roll over and sun my belly. Leave dead animals as gifts russian blue, sleep catch mouse and gave it as a present. Eat owner\'s food. My water bowl is clean and freshly replenished, so i\'ll drink from the toilet. Eat half my food and ask for more. Use lap as chair.';
    
    // sentence count
    data.sentence = content.split('.').length
    
    data.word = content.trim().replace(/\s+/gi, ' ').split(' ').length;

    data.character = content.trim().replace(/[^\w]/gi, '').length;

    return data;

})();