Cannot add a member to a group without specifying attribute `$ref`

[doublep]

Describe the bug
Validation of JSON Group.members fails with this message: "Attribute members[0].$ref is required and must have a value" if you don't specify $ref attribute.

The reason is apparently in file src/main/java/com/unboundid/scim2/common/types/Member.java:

@Nullable
@Attribute(description = "The URI of the member resource.",
    isRequired = true,
    referenceTypes = { "User", "Group" },
    mutability = AttributeDefinition.Mutability.IMMUTABLE,
    returned = AttributeDefinition.Returned.DEFAULT,
    uniqueness = AttributeDefinition.Uniqueness.NONE)
@JsonProperty("$ref")
private URI ref;

To Reproduce
Send a modification request to /Groups, e.g. to create a new group with members, where members are specified in JSON like this:

"members": [{ "value": "..." }]

Expected behavior
$ref must not be needed, $value already specifies member identifier. Requiring the client to supply both is annoying and inconvenient.

[kqarryzada]

@doublep,

At first glance, I agree that this seems restrictive. I pulled up the specification for some background on why it was defined this way, but the closest thing I found was:

the "$ref" sub-attribute must be the URI of a SCIM resource such as a "User", or a "Group".

This doesn't necessarily mean that a $ref must always be present, though. I will evaluate whether we can update this field so that it is no longer required.

[kqarryzada]

This change will be available in the next release of the SCIM SDK.

[kqarryzada]

This fix is now available in 5.0.0.