rawmoves.js

 this.add({
        role: "movement",
        cmd: "rawMoves",
    }, (msg, reply) => {
        var err = null;
        var rawMoves = [];

        var pos = msg.piece.position;

        switch (msg.piece.piece) {
        case 'R':
            rawMoves = rankAndFile(pos);
            break;
        case 'B':
            rawMoves = diagonal(pos);
            break;
        case 'Q':
            rawMoves = rankAndFile(pos)
                .concat(diagonal(pos));
            break;
        case 'K':
            rawMoves = rankAndFile(pos, 1)
                .concat(diagonal(pos, 1))
            break;
        default:
            err = "unhandled " + msg.piece;
            break;
        };

        reply(err, rawMoves);
    });