$ should be a JSON array. Check that value(s) appear within square brackets, [...]

[kathryn-ods]

Error occured when testing this - the issue is I am only testing one statement and forgot to put [] around the whole statement. I think the error message could be clearer as I wasn't sure what $ meant at first? Kadie - thoughts?

{
  "statementId": "019a93f1-e470-42e9-957b-03559861b2e2",
  "declarationSubject": "c359f58d2977",
  "statementDate": "2020-03-04",
  "recordId": "10478c6cf6de",
  "recordType": "person",
  "recordDetails": {
    "isComponent": false,
    "personType": "knownPerson",
    "identifiers": [
      {
        "id": "test",
        "scheme": "GBR-TAXID"
      }
    ]
  }
}

[kd-ods]

Ah. That JSON snippet is a bit of a special case. If you paste this in, you'll see the same error message generated, but about a different thing:

[{
  "statementId": "019a93f1-e470-42e9-957b-03559861b2e2",
  "declarationSubject": "c359f58d2977",
  "statementDate": "2020-03-04",
  "recordId": "10478c6cf6de",
  "recordType": "person",
  "recordDetails": {
    "isComponent": false,
    "personType": "knownPerson",
    "identifiers": 
      {
        "id": "test",
        "scheme": "GBR-TAXID"
      }
  }
}
]

So you get the more helpful message:

identifiers should be a JSON array. Check that value(s) appear within square brackets, [...]

With your JSON snippet, as always the DRT expects the root JSON document to be an array. But there is no key to which the array is a value, hence the unhelpful message.

So I think that this is probably best handled with a bit of coding logic from @radix0000. (And I do think the example you raise is a common mistake, @kathryn-ods, so worth some special handling.)

@radix0000 can you detect when the it's the root value that isn't an array, and in that case use the message:

The dataset should be a JSON array. Check that the object(s) appear within square brackets, [...]

.. and in all other cases use the error message as-is?