[ATLAS-2933] Empty array attributes are returned as null instead of an empty list

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Assignee: Le Ma
• Reporter: Cade Parker
• Created: 23/Oct/18 23:11
• Updated: 13/Aug/19 00:52
• Resolved: 03/Apr/19 12:27

Description

 

Given the following entity def:

{
 "entityDefs": [
   {
     "name": "ExampleType",
     "superTypes": [],
     "typeVersion": "0.1",
     "attributeDefs": [
       {
         "name": "things",
         "typeName": "array<string>",
         "cardinality": "SINGLE",
         "isIndexable": false,
         "isOptional": false,
         "isUnique": false
       }
     ]
   }
 ]
}

I can POST a new entity with an empty array for the things attribute successfully:

POST /api/atlas/v2/entity

{
 "entity":{
 "typeName":"ExampleType",
 "attributes":{
   "things": []
 },
 "guid":"-thing",
 "version":1
 }
}

But when i GET the entity by guid, the attribute is null instead of the empty list:

GET /api/atlas/v2/entity/guid/d5e33187-3293-4206-bcb8-807dc87c1440

{
 "referredEntities": {},
 "entity": {
 "typeName": "ExampleType",
 "attributes": {
   "things": null
 },
 "guid": "d5e33187-3293-4206-bcb8-807dc87c1440",
 "status": "ACTIVE",
 "createdBy": "admin",
 "updatedBy": "admin",
 "createTime": 1540335741854,
 "updateTime": 1540335741854,
 "version": 1
 }
}

Atlas should preserve the original value of the create request as an empty list. Returning null here causes further confusion, because the attribute is defined with `isOptional: false` so any consumer of the entity would reasonably expect a non-null value.

I tested this behavior against Atlas versions 1.0.0 and 1.1.0

Issue Links

• links to: GitHub Pull Request #29
• links to: GitHub Pull Request #37