Swap fleets using keyboard shortcut in Istrolid

fleetSwap.js

/*
 * Swapping fleet using shift + arrow up/down key.
 * Use alt-shift-num to select one of the first 10 fleets
 */

var fleetSwap = window.fleetSwap || {
    onkeydown: ControlsMode.prototype.onkeydown
}

ControlsMode.prototype.onkeydown = function(e) {
    const saveAndRefresh = () => {
        account.save();
        onecup.refresh();
    };

    if(e.shiftKey && e.key == "ArrowUp") {
        if(commander.fleet.selection.row > 0) {
            commander.fleet.selection.row -= 1;
            saveAndRefresh();
        }
        return;
    } else if(e.shiftKey && e.key == "ArrowDown") {
        commander.fleet.selection.row += 1;
        saveAndRefresh();
        return;
    } else if(e.shiftKey && e.altKey) {
        let row = e.which - 49;
        if(row === -1) row += 49;
        if(row >= 0 && row < 49) { // is numeric key
            commander.fleet.selection.row = row;
            saveAndRefresh();
            Object.defineProperty(e, 'which', { get: () => 0 }); // Prevent battleMode spawn unit
            return;
        }
    }

    return fleetSwap.onkeydown.call(this, e);
};

Nice!