example_return_a_promise.js

 parse: function(feed) {

        return new Promise(function(resolve, reject) { // wrap into function to return a promise
            sails.log.info('downloading feed ' + feed.id );
            importcsv_service.parsecsvfeed.downloadfile(feed,csv_dir).then(function(file){
                sails.log.info('file '+ feed.id +' downloaded succesfully');
                return file;
            }).then(function(file) {
                console.log("reading" + file);
                importcsv_service.parsecsvfeed.convert_line_to_json(file).then(function(data) {
                    sails.log.info('feed '+ feed.id +' can be read succesfully :-)');
                    resolve(data); //<== Over here i return a promise, see it as true, you can also do resolve(true)

                }, function(csvparserror){
                    sails.log.error(csvparserror);
                    return reject(new Error(csvparserror)); //<== Over here i return a promise, see it as true, you can also do reject(false)

                });
                //
            },function(connection_error) {
                sails.log.error(connection_error);
                return reject(new Error(connection_error));
            });
        });