Parse JavaScript SDK Query Not Working - parse-platform

Question

I would like to know why could you get this error:
Error code: 102, error message: $in requires an array
I'm using Parse JavaScript SDK.
The data structure it this one:
The source code of the function is this one:
Parse.Cloud.define(
"unfollow",
function(request, response) {
var currentUserID = request.params.currentuser;
var followedUserID = new Array(request.params.followeduser);
var queryRemoveFollower = new Parse.Query("userRelation");
queryRemoveFollower.containedIn("userObjectId", followedUserID);
queryRemoveFollower.find({
success: function(result) {
for(var i=0; i<result.length; i++) {
result[i].remove("followers", currentUserID);
result[i].save();
}
var stopFollowingQuery = new Parse.Query("userRelation");
stopFollowingQuery.equalTo("userObjectId", currentUserID);
stopFollowingQuery.find({
success: function(result) {
for(var i=0; i<result.length; i++) {
result[i].remove("following", followedUserID);
result[i].save();
}
response.success("Unfollow succesful!");
},
error: function(error) {
response.success("Something went wrong. Error code: " + error.code + ", error message: " + error.message);
}
});
},
error: function(error) {
response.success("Something went wrong. Error code: " + error.code + ", error message: " + error.message);
}
});
}
);
I know that the data is being currently sent:
fn_unfollow.parse_data_user_id = ruWNYycty7
fn_unfollow.idOfTheUserToUnfollow = KcCNa39sgk
Thanks in advance for the help!!

Answer 1

The problem in your code is the line:
var followedUserID = new Array(request.params.followeduser);
JavaScript's Array constructor has two possible constructors:
new Array(element0, element1, ..., elementN)
new Array(arrayLength)
Since request.params.followeduser is an integer, folowedUserID is being initalized as a EMPTY array with length of request.params.followeduser.
The fix is to use either of the following (untested...):
var followedUserID = new Array(1, request.params.followedUser);
or (preferred):
var followedUserId = [request.params.followedUser];