CloudKit JS query with IN comparator and array value

Question

I'm doing a CloudKit JS web app.

I'm facing a problem doing a query with the comparator IN. I tried in with different values for the fieldValue property but none of them succeed.

Here is the query:

  var publicIDs = ['TEST_ID'];  
  var query = {  
            recordType: 'PublicInfo',  
            filterBy: [{  
                      fieldName: 'publicID',  
                      comparator: 'IN',  
                      fieldValue: { value:  publicIDs}  
            }]  
  };  
  publicDB.performQuery(query) ...  

When I do that, I get the following error result:

_ckErrorCode: "BAD_REQUEST"  
_extensionErrorCode: undefined  
_reason: "BadRequestException: Invalid value, expected type STRING but actual value was a list with objects of class java.lang.String"  
_recordName: undefined  
_redirectURL: undefined  
_retryAfter: undefined  
_serverErrorCode: "BAD_REQUEST"  
_subscriptionID: undefined  
_uuid: "5470373b-8665-49a0-8c3c-ebbd4df37bbd"  
_zoneID: undefined  
message: "BadRequestException: Invalid value, expected type STRING but actual value was a list with objects of class java.lang.String"  

If I replace

  fieldValue: { value:  publicIDs}  

with

  fieldValue: { value:  publicIDs, type: 'list' }  

or even

  fieldValue: { value:  publicIDs, type: 'array' }  

I get the following error result:

_ckErrorCode: "BAD_REQUEST"  
_extensionErrorCode: undefined  
_reason: "BadRequestException: Unexpected input"  
_recordName: undefined  
_redirectURL: undefined  
_retryAfter: undefined  
_serverErrorCode: "BAD_REQUEST"  
_subscriptionID: undefined  
_uuid: "ccb1d8bb-03e6-476b-b111-89fe3cddbf6d"  
_zoneID: undefined  
message: "BadRequestException: Unexpected input"  

If I use the comparator "EQUALS" and a single value instead of an array in the query, I get the correct result without error.

The Cloudkit JS documentation says that we can use the "IN" comparator. But there is no more information, i.e. how to specify the array values in the query.

Does anyone know the correct syntax to use ?