gistfile1.txt

Template.newLineItem.helpers({
    search : function(query, callback) {
        console.log('in search');
        Meteor.call('searchProducts', query, {}, function(err, res) {
            if (err) {
                console.log(err);
                return;
            }
            console.log(callback);
            callback(res.map(function(v){
                console.log('test');
                return {label: v.itemNumber, value: v._id}; }));
        });
    }
});

console.log of callback returns this:

function render(suggestions) {                                                                         // 1242
                    if (!that.canceled && query === that.query) {                                                      // 1243
                        that._render(query, suggestions);                                                              // 1244
                    }                                                                                                  // 1245
                }