GET /ngsi-ld/v1/types returns an empty JSONarray when EntityTypeList is empty

[fisuda]

NGSI-LD spec specifies that GET /ngsi-ld/v1/types returns a EntityTypeList type, unless details=true is specified.
But it returns an empty JSONarray when EntityTypeList is empty.

$ curl orion-ld:1026/ngsi-ld/v1/types
[]

I think that it should returns an empty JSONobject or an JSONobject including a empty typeList as shown:

{}

or

{
  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld",
  "id": "urn:ngsi-ld:EntityTypeList:b6c79274-78c4-11eb-a948-0242ac12000f",
  "type": "EntityTypeList",
  "typeList": []
}

I tested this using Orion 0.6.1.

$ curl orion-ld:1026/version
{
  "orionld version": "0.6.1",
  "orion version":   "1.15.0-next",
  "uptime":          "0 d, 0 h, 12 m, 26 s",
  "git_hash":        "nogitversion",
  "compile_time":    "Thu Jan 28 10:52:23 UTC 2021",
  "compiled_by":     "root",
  "compiled_in":     "buildkitsandbox",
  "release_date":    "Thu Jan 28 10:52:23 UTC 2021",
  "doc":             "https://fiware-orion.readthedocs.org/en/master/"
}

$ curl orion-ld:1026/ngsi-ld/v1/types | jq .
{
  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld",
  "id": "urn:ngsi-ld:EntityTypeList:b6c79274-78c4-11eb-a948-0242ac12000f",
  "type": "EntityTypeList",
  "typeList": [
    "https://uri.fiware.org/ns/data-models#TemperatureSensor"
  ]
}

[kzangeli]

Yes, you are probably right. I will look into this.
The response type of GET /types was recently changed and while the normal case (some type found) has been changed to return what the NGSI-LD API spec now states, this corner-case was probably forgotten.

I promise to look into this and if we (well, you :)) are right, to fix it ASAP!

Thanks!

[fisuda]

I have confirmed that this issue has been fixed. I appreciate your prompt response.

$ curl -s orion-ld:1026/ngsi-ld/v1/types | jq .
{
  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld",
  "id": "urn:ngsi-ld:EntityTypeList:80adecbc-7944-11eb-9ae6-0242ac150012",
  "type": "EntityTypeList",
  "typeList": []
}

$ curl -s orion-ld:1026/version
{
  "orionld version": "post-v0.6",
  "orion version":   "1.15.0-next",
  "uptime":          "0 d, 0 h, 21 m, 27 s",
  "git_hash":        "nogitversion",
  "compile_time":    "Sat Feb 27 12:36:35 UTC 2021",
  "compiled_by":     "root",
  "compiled_in":     "buildkitsandbox",
  "release_date":    "Sat Feb 27 12:36:35 UTC 2021",
  "doc":             "https://fiware-orion.readthedocs.org/en/master/"
}

$ docker images
fiware/orion-ld                          0.7-PRE-71                     d82d77013395   9 hours ago      978MB