Items not deleting from mongodb when doDelete() called from the sync client

[damienomurchu]

Issue

Data items not deleting from collection in mongo after doDelete() is called from the client

Steps to reproduce

• call doCreate() in the client code to create a data item to sync with the backend & into mongo
• call doDelete() on that created data item to delete it
• check data entry in mongodb to confirm failure to delete

A (very rough) set of client & server sync code if needed can be found here to reproduce the issue

Screenshots of issue

Before & after in mongodb collection:

Further info

• the handling code in for doDelete() in the backend in fh-sync relies on the uid of the data item to be deleted being the same as the mongo _id in order to be able to delete the entry successfully

    doDelete: function(dataset_id, uid, meta_data, cb) {
      debug(
        '[%s] doDelete :: %s :: meta=%j', dataset_id, uid, meta_data);
      mongo.collection(dataset_id).remove({"_id": convertToObjectId(dataset_id, uid)}, cb);
    },

function convertToObjectId(datasetId, originalId) {
  var newObjectId = originalId;
  if (ObjectID.isValid(originalId)) {
    newObjectId = ObjectID(originalId);
  } else {
    debug('[%s] Invalid objectId value : %s', datasetId, originalId);
  }
  return newObjectId;
}

var ObjectID = require('mongodb').ObjectID;

• the uid and the mongo _id are usually synchronised by the sync framework to be the same, but this does not seem to be happening, thus the deletion breaks down
• this issue should affect other operations (such as update/ read a specific entry) to fail also, but have confirmed this yet

@wtrocki @aidenkeating @wei-lee pinging you on this as requested