legalmoves.js

    this.add({
        role: "movement",
        cmd: "legalSquares",
    }, (msg, reply) => {
        const isPawn = msg.piece.piece === 'P';
        const isKnight = msg.piece.piece === 'N';

        this.act({
            role: "movement",
            cmd: "rawMoves",
            piece: msg.piece,
            isPawn: isPawn,
            isKnight: isKnight
        }, (err, msg) => {
            const squared = [];

            msg.forEach((move) => {
                if (move.file >= 'a' && move.file <= 'h') {
                    if (move.rank >= 1 && move.rank <= 8) {
                        squared.push(move)
                    }
                }
            })

            reply(null, squared);
        });
    })