Lane action in LaneStore for dragging a note over a note or an empy lane instead of attachToLane. Source: http://survivejs.com/webpack_react/implementing_dnd/

move.js

  queryIds(searchIds){
    let ids = [...searchIds];

    return this.lanes.reduce((result, lane, laneIdx) => {
      // no more ids
      if(!ids.length) return result;

      const notes = lane.notes;
      const idsIndexOfLane = ids.indexOf(lane.id);

      // current lane id is included in searchIds
      if(idsIndexOfLane !==-1){

        const noteIdx = 0;
        const isLane = true;

        result[lane.id] = {notes, noteIdx, lane, laneIdx, isLane};

        ids.splice(idsIndexOfLane, 1);

        return result;
      }
 
      // check current lane note ids for search ids
      ids = ids.filter(id => {

        const noteIdx = notes.indexOf(id);
        if(noteIdx === -1) return true;

        result[id] = {notes, noteIdx, lane, laneIdx};
        return false;
      });

      return result;
    }, {});
  }

  move({sourceId, targetId}){

    const {[sourceId]: source, [targetId]: target} = 
      this.queryIds([sourceId, targetId]);

    if(target.isLane && target.notes.length ) return;

    const lanes = [...this.lanes];
    const slane = lanes[source.laneIdx] =
      {...source.lane, notes: [...source.notes]};
    let tlane = slane;

    if(source.lane.id !== target.lane.id){
      tlane = lanes[target.laneIdx] =
        {...target.lane, notes: target.notes.slice()};
    }

    slane.notes.splice(source.noteIdx, 1);
    tlane.notes.splice(target.noteIdx, 0, sourceId);
    
    this.setState({lanes});
  }