hardmode.js

if (this.hardMode) {
    var t = (
        function() {
            var thisGuess = s;
            var previousGuess = this.boardState[this.rowIndex - 1];
            var previousEvaluation = this.evaluations[this.rowIndex - 1];

            if (!thisGuess || !previousGuess || !previousEvaluation) {
                return {
                    validGuess: true,
                };
            }

            for (var pos = 0; pos < previousEvaluation.length; pos++) {
                if (previousEvaluation[pos] === CORRECT && thisGuess[pos] !== previousGuess[pos]) {
                    return {
                        validGuess: false,
                        errorMessage: "".concat($a(pos + 1), " letter must be ").concat(previousGuess[pos].toUpperCase())
                    };
                }
            }

            var letterCountsInPreviousGuess = {};
            for (var pos = 0; pos < previousEvaluation.length; pos++) {
                if ([CORRECT, PRESENT].includes(previousEvaluation[pos])) {
                    if (letterCountsInPreviousGuess[previousGuess[pos]]) {
                        letterCountsInPreviousGuess[previousGuess[pos]] += 1;
                    } else {
                        letterCountsInPreviousGuess[previousGuess[pos]] = 1;
                    }
                }
            }

            var letterCountsInThisGuess = thisGuess.split("").reduce(
                (function(letterCountsInThisGuess, letter) {
                    if (letterCountsInThisGuess[letter]) {
                        letterCountsInThisGuess[letter] += 1;
                    } else {
                        letterCountsInThisGuess[letter] = 1;
                    }
                    return letterCountsInThisGuess;
                }),
                {}
            );

            for (var letter in letterCountsInPreviousGuess) {
                if ((letterCountsInThisGuess[letter] || 0) < letterCountsInPreviousGuess[i]) {
                    return {
                        validGuess: false,
                        errorMessage: "Guess must contain ".concat(letter.toUpperCase())
                    };
                }
            }

            return {
                validGuess: true
            }
        }()
    )
      , n = t.validGuess
      , o = t.errorMessage;
    if (!n)
        return a.setAttribute("invalid", ""),
        void this.addToast(o || "Not valid in hard mode")
}