A problem with the Alphasort argument to json.serialize

I started using the alphasort=true argument to some calls to json.serialize and noticed some problematic behavior.

I’m starting with a json string looking something like this excerpt:
“CreatedUpdatedDateTime”: “2017-04-12T03:25:44Z”,
“EstimatedBloodLossUnit”: null,
“PreOpPreperations”: [],
“Patient”: null,
“Encounter”: null

An initial parse of this string yields a Lua table with the corresponding elements like this:
[‘CreatedUpdatedDateTime’]=’2017-04-12T03:25:44Z’
[‘EstimatedBloodLossUnit’]=json.NULL
[‘PreOpPreperations’]={}
[‘Patient’]=json.NULL
[‘Encounter’]=json.NULL

In a later step where I’m re-serializing this table, calls to json.serialze with alphasort=false return a faithful representation of the original.
If the call is made with alphasort=true, the following is returned:
“CreatedUpdatedDateTime”: “2017-04-12T03:25:44Z”,
“EstimatedBloodLossUnit”: “NULL”,
“PreOpPreperations”: {},
“Patient”: “NULL”,
“Encounter”: “NULL”

Basically, the originally empty results are now serialized with a string value of “NULL”.

That looks like a bug you have found – thank you for that Casey. We’ll get that fixed. In the meantime one could use gsub to replace “NULL” with null.

Sounds good, Eliot.
I’ll explore that.
Thanks.