Querying collection using array meteor js - arrays

Question

I have this weird scenario which I do not know what the problem is exactly. While troubleshooting I found out that the subscription is published and subscribed to because it's printed on the console. When I executed this on Firefox console it displayed this error SyntaxError: missing : after property id [Learn More]. I don't know what the syntax error is as the same code works on other files.
If I remove fetch() function from it it displayed 2 obects being published. This means the publish and sbscription is working. What am I to do right?
This is the event function
students(){
let myslug = trimInput(Session.get('ReceivedSlug'));
if (myslug) {
let mySchoolDoc = SchoolDb.findOne({slug: myslug});
if (mySchoolDoc) {
let arrayModuleSchool = StudentSchool.find({schoolId: mySchoolDoc._id});
if (arrayModuleSchool) {
var arrayStudentIds = [];
arrayModuleSchool.forEach(function(studentSchool){
arrayStudentIds.push(studentSchool.studentId);
});
let subReadiness = SchoolStudents.find({ _id: {$in: arrayStudentIds}}).fetch();
if (subReadiness) {
console.log('before readiness --- ' +arrayStudentIds);
console.log('after seting --- ' +subReadiness);
return subReadiness;
}
}
}
}
}
This is the publish function
Meteor.publish('PaginatedStudents', function (skipCount) {
check(skipCount, Number);
user = Meteor.users.findOne({_id:this.userId})
if(user) {
if(user.emails[0].verified) {
return SchoolStudents.find({userId: this.userId}, {limit: 2, skip: skipCount});
} else {
throw new Meteor.Error('Not authorized');
return false;
}
}
});
Tracker to rerun when things changes
Session.setDefault('skip', 0);
Tracker.autorun(function () {
Meteor.subscribe('PaginatedStudents', Session.get('skip'));
});