basic-autocorrect.js

    const wordList = {
        sacrilege: {popularity: 0.5207411547},
        sarcasm: {popularity: 0.1913595276},
        said: {popularity: 0.736293578},
        sardine: {popularity: 0.2439570583},
        sars: {popularity: 0.6371759558},
        saw: {popularity: 0.1695272778},
        say: {popularity: 0.8312312658},
        scare: {popularity: 0.3623531581},
        sea: {popularity: 0.6786234},
        seal: {popularity: 0.5311880343},
        sear: {popularity: 0.2651375578},
        search: {popularity: 0.1371922207},
        seen: {popularity: 0.04845264854},
        shalvah: {popularity: 0.3734743679},
        shepard: {popularity: 0.2800899325},
        shrink: {popularity: 0.4796703544},
        simple: {popularity: 0.965004213},
        simpleton: {popularity: 0.5028959222},
        sinister: {popularity: 0.3120875969},
        sin: {popularity: 0.5613698484},
        soon: {popularity: 0.3977505837},
        soothe: {popularity: 0.5668864284},
        smosh: {popularity: 0.8812294656},
        substitute: {popularity: 0.767571411},
        subtraction: {popularity: 0.4938204045},
    };

    var TrieSearch = require('trie-search');

    var ts = new TrieSearch();

    ts.addFromObject(wordList);

    function getAutoCorrectSuggestions(input) {

        let corrections = [];

        const characters = [...input];

        let substring = "";
        let indexToStopAt = characters.length; // Start with whole word, minus the last letter...

        while (corrections.length === 0 && indexToStopAt > 1) { // ...and keep going backwards if we don't find any corrections
            indexToStopAt--;
            substring = input.substring(0, indexToStopAt);

            console.log("Working with substring " + substring)

            // This will return all words starting with the substring
            corrections = corrections.concat(ts.get(substring));
        }

        return corrections;
    }

getAutoCorrectSuggestions("simper");

// Some things we could improve on:
// - Ranking by popularity
// - Rank by character proximity on user's keyboard layout
// - Provide corrections for positions other than the end
// - Support variable length corrections (eg payback -> playback and vice versa)
// - Specify max length of corrections