A required field cannot be nested beneath an absent optional field

I'm having some problems after #402, but don't know if this suppose to be in this ways or not.

I have a json with structure like that:

"aa": [
  {
    "bb": "some",
    "cc": {
      "dd": "some"
    }
  },
  {
    "bb": "something else",
    "cc": {
      "dd": "something more"
    }
  }
]

So, "cc" node is optional, but "dd" node is required.

After #402 I have to declare both "cc" and "dd" as optional, otherwise test fails. Which feels kind of wrong - if "cc" present, then it MUST have "dd".

[wilkinsona]

Interesting use case. I hadn't considered people nesting a required field beneath an optional one, and wanting the required field to only actually be required when the optional field is present.

The behaviour you're seeing now has always been the case without an array, for example with a payload like this:

"aa": {
  "bb": "some",
  "cc": {
    "dd": "some"
  }
}

You'd have the same problem if aa.cc was optional and aa.cc.dd was required. #402 has just made this apply to arrays too by removing an inconsistency.

I'll see what can be done to support your requirement. It may be possible to fix this in 1.2.x if it can be done without an API change.

[joemccall86]

A more concrete example is shapes on a map. For example, our REST endpoint will index shapes. Each shape has an optional center point, optional points for polygons, and optional pointNorthEast and pointSouthWest for rectangles. If these points exist, they must have a latitude and longitude.

Sample response:

[ {
  "id" : 1,
  "alpha" : 1.0,
  "colorHex" : "#FF0000",
  "colorLightenedHex" : "#FFCCCC",
  "type" : "CIRCLE",
  "center" : {
    "id" : 1,
    "latitude" : 21.234589,
    "longitude" : -81.345897
  },
  "radius" : 35.0
}, {
  "id" : 2,
  "alpha" : 0.75,
  "colorHex" : "#FF0000",
  "colorLightenedHex" : "#FFCCCC",
  "type" : "POLYGON",
  "points" : [ {
    "id" : 2,
    "latitude" : 21.234589,
    "longitude" : -81.345897
  }, {
    "id" : 3,
    "latitude" : 21.222222,
    "longitude" : -81.888888
  } ]
}]

// ...
responseFields(
                        fieldWithPath('[].points').optional().description('the list of points on the polygon or polyline, if applicable'),
                        fieldWithPath('[].radius').optional().description('the radius of the circle, if applicable'),
                        fieldWithPath('[].center').optional().description('the center point of the circle, if applicable'),
                        fieldWithPath('[].pointNorthEast').optional().description('the north-east corner of the rectangle, if applicable'),
                        fieldWithPath('[].pointSouthWest').optional().description('the south-west corner of the rectangle, if applicable')

                )
                        .andWithPrefix('[].center.', pointDescriptorsWithId)
                        .andWithPrefix('[].points[].', pointDescriptorsWithId)
                        .andWithPrefix('[].pointNorthEast.', pointDescriptorsWithId)
                        .andWithPrefix('[].pointSouthWest.', pointDescriptorsWithId)
// ...

This test used to pass in 1.2.1, but fails under 1.2.2 because of this issue.

[wilkinsona]

I've prototyped something and I think this requirement can be supported in 1.2.x as it doesn't require an API change

[wilkinsona]

@joemccall86 @ghost When this build has finished, a fix will be available in 1.2.3.BUILD-SNAPSHOT available from https://repo.spring.io/libs-snapshot. If you have a moment, please give it a try and check that it fixes things for you.