`TypedValue(Type.jsonbArray, ...)` cannot express `NULL`

[jonasfj]

If you want to send [NULL, 'null', '{"key": "value"}']::jsonb[] to postgres there are means to do so.

I think the fix is the allow us to write:

TypedValue(
  Type.jsonbArray,
  [
     TypedValue(type.jsonbArray, null, isSqlNull: true), // NULL
     null,                                               // 'null'::jsonb
     {"key": "value"},                                   //'{"key": "value"}'::jsonb
  ],
  isSqlNull: false,
),

Probably, something we can fix in:

postgresql-dart/lib/src/types/binary_codec.dart

Lines 583 to 603 in ffcd22a

	case TypeOid.jsonbArray:
	{
	if (input is List) {
	final objectsArray = input
	.map(_jsonFusedEncoding(encoding).encode)
	.toList();
	return _writeListBytes<List<int>>(
	objectsArray,
	3802,
	(item) => item.length + 1,
	(writer, item) {
	writer.writeUint8(1);
	writer.write(item);
	},
	encoding,
	);
	}
	throw FormatException(
	'Invalid type for parameter value. Expected: List Got: ${input.runtimeType}',
	);
	}

All we really need is a sentinel value that acts as SQL NULL, we probably don't even need to change anything we can just interpret TypedValue(type.jsonbArray, null, isSqlNull: true) as such sentinel.

[jonasfj]

In practice one can work around this using:

TypedValue(
  Type.textArray,
  [
     null
     json.encode(null),
     json.encode({"key": "value"}),
  ],
),

So long as one remembers to cast this argument to $1::jsonb[]