Misago/frontend/src/reducers/tick.js

export var initialState = {
  tick: 0
};

export const TICK = 'TICK';

export function doTick() {
  return {
    type: TICK
  };
}

export default function tick(state=initialState, action=null) {
  if (action.type === TICK) {
    return Object.assign({}, state, {
        tick: state.tick + 1
    });
  } else {
    return state;
  }
}