Takes a collection of data and removes any duplicates, based on key, thare are not null. If the key value is null, it is not filtered out.

dedupe-not-null-by-key.js

var deDupeNonNull = function(data, key){
  var used = [];
  return _.reduce(data, function(cur, data){
    if(!!data[key] && !_.includes(used, data[key])){
      used.push(data[key]);
      cur.push(data);
    }
    else if(!data[key]) {
      cur.push(data);
    }
    return cur;
  }, []);
};