koozdra

shuffle_array = arr =>
  arr
    .map(a => [a, Math.random()])
    .sort(([, lr], [, rr]) => lr - rr)
    .map(([a]) => a);

user_action_for_state = (state, randy) => {
  if (state === 'p' || state === 'ps' || state === 'psa' || state === 'psam') {
    if (randy < 0.7) {
      return primary_action_names[state[state.length - 1]];

koozdra

a = [ { name: 'bill', group: 'b' },
  { name: 'ann', group: 'a' },
  { name: 'ken', group: 'k' },
  { name: 'alex', group: 'a' } ]

_.reduce((sum, v) => {
  const { name, group } = v;
  const current = _.getOr([], [group, name])(sum);
  return _.set([group, name], [...current, v])(sum);
}, {})(a);