Add conformance test for Dart UPB VM

PiperOrigin-RevId: 556057266

conformance/conformance_dart.dart

@@ -0,0 +1,106 @@
+import 'package:pb_runtime/ffi/bytes.dart';
+import 'package:third_party.protobuf.conformance/conformance.upb.dart';
+import 'package:third_party.protobuf/test_messages_proto2.upb.dart';
+import 'package:third_party.protobuf/test_messages_proto3.upb.dart';
+
+import 'dart:io';
+import 'package:pb_runtime/pb_runtime.dart' as pb;
+
+List<int>? readFromStdin(int numBytes) {
+  final bytesOut = <int>[];
+  for (var i = 0; i < numBytes; i++) {
+    final byte = stdin.readByteSync();
+    if (byte == -1) return null;
+    bytesOut.add(byte);
+  }
+  return bytesOut;
+}
+
+int readLittleEndianIntFromStdin() {
+  final buf = readFromStdin(4);
+  if (buf == null) return -1;
+  return (buf[0] & 0xff) |
+      ((buf[1] & 0xff) << 8) |
+      ((buf[2] & 0xff) << 16) |
+      ((buf[3] & 0xff) << 24);
+}
+
+void writeLittleEndianIntToStdout(int value) {
+  final buf = <int>[];
+  buf.add(value & 0xff);
+  buf.add((value >> 8) & 0xff);
+  buf.add((value >> 16) & 0xff);
+  buf.add((value >> 24) & 0xff);
+  stdout.add(buf);
+}
+
+ConformanceResponse doTest(ConformanceRequest request) {
+  final response = ConformanceResponse();
+  pb.GeneratedMessage? testMessage;
+  final messageType = request.messageType;
+  final isProto3 =
+      messageType == 'protobuf_test_messages.proto3.TestAllTypesProto3';
+
+  if (!isProto3 &&
+      messageType != 'protobuf_test_messages.proto2.TestAllTypesProto2') {
+    throw ArgumentError('Invalid message type $messageType');
+  }
+
+  switch (request.whichPayload) {
+    case ConformanceRequest_payload.protobufPayload:
+      try {
+        testMessage = isProto3
+            ? TestAllTypesProto3.fromBinary(request.protobufPayload.data)
+            : TestAllTypesProto2.fromBinary(request.protobufPayload.data);
+      } catch (e) {
+        final parseErrorResponse = ConformanceResponse();
+        parseErrorResponse.parseError = '$e';
+        return parseErrorResponse;
+      }
+      break;
+    default:
+      response.skipped = 'Only protobuf payload input is supported';
+      return response;
+  }
+
+  switch (request.requestedOutputFormat) {
+    case WireFormat.PROTOBUF:
+      try {
+        response.protobufPayload =
+            Bytes(pb.GeneratedMessage.toBinary(testMessage));
+      } catch (e) {
+        response.serializeError = '$e';
+      }
+      break;
+    default:
+      response.skipped = 'Only protobuf payload output is supported';
+  }
+
+  return response;
+}
+
+Future<bool> doTestIo() async {
+  final msgLength = readLittleEndianIntFromStdin();
+  if (msgLength == -1) return false; // EOF
+  final serializedMsg = readFromStdin(msgLength);
+  if (serializedMsg == null) {
+    throw 'Unexpected EOF from test program.';
+  }
+  final request = ConformanceRequest.fromBinary(serializedMsg);
+  final response = doTest(request);
+  final serializedOutput = pb.GeneratedMessage.toBinary(response);
+  writeLittleEndianIntToStdout(serializedOutput.length);
+  stdout.add(serializedOutput);
+  await stdout.flush();
+  return true;
+}
+
+void main() async {
+  await pb.initGlobalInstance();
+  var testCount = 0;
+  while (await doTestIo()) {
+    testCount++;
+  }
+  stderr.writeln(
+      'ConformanceDart: received EOF from test runner after $testCount tests');
+}