promises.js

var promisify = require("es6-promisify"); // you can also look for a promisifyAll equivalent, but for the sake of demonstration

function findText(freeText, result) {
  var query = {
    index: result.teamUnique + "_team",
    type: result.username,
    body: {
      query: {
        match: {
          name: freeText
        }
      }
    }
  }

  return elasticsearch_client.search(query);
}

exports.findResultsByFreeText = function(req, res, next, freeText) {
  //TODO: Check if request contains facet params, and filter accordingly
  tryPromise(function() { // https://gist.github.com/joepie91/255250eeea8b94572a03
    return getListOfTeams(req.user.username);
  }).then(function(results) {
    return promiseMap(findText.bind(null, freeText), results);
  }).then(function(searchResults) {
    req.results = searchResults;
    next();
  }).catch(function(err) {
    // you should normally not log this here, but let it be handled by express-promise-router instead
    console.log("An error occurred somewhere:", err);
  });
});
  
var getListOfTeams = function(username) {
  return tryPromise(function() {
    if(!username){
      throw new Error("An error message goes here"); // an object is not an Error!
    }
    
    var findMethod = promisify(TeamsToUsers.find).bind(TeamsToUsers); // this would be a lot nicer with promisifyAll...
    
    return findMethod({
      username: username
    });
  }).catch(function(err) {
    // you'd ideally want to filter by error type here, but that's not really possible with ES6 promises...
    throw new Error("User not found"); // again, object != Error
  })
}

I understood bits and pieces. Will likely get further queries answered on IRC tomorrow. Thanks!

@joepie91, in line 24 , how does each result entry gets binded to findText() ? Will you explain this a little bit? Thanks :)