translate missing ">" fasta error code to analyzer error

pkg/analyzer/test/generated/scanner_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.test.generated.scanner_test;
 
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
@@ skipping 61 matching lines @@
   void test_setOffset() {
     CharSequenceReader baseReader = new CharSequenceReader("xyzzy");
     CharacterRangeReader reader = new CharacterRangeReader(baseReader, 1, 4);
     reader.offset = 2;
     expect(reader.offset, 2);
   }
 }
 
 @reflectiveTest
 class LineInfoTest extends EngineTestCase {
+  void test_translate_missing_closing_gt_error() {
+    // Ensure that the UnmatchedToken error for missing '>' is translated
+    // to the correct analyzer error code.
+    // See https://github.com/dart-lang/sdk/issues/30320
+    String source = '<!-- @Component(';
+    GatheringErrorListener listener = new GatheringErrorListener();
+    _scanWithListener(source, listener);
+    listener.assertErrorsWithCodes(const [
+      ScannerErrorCode.EXPECTED_TOKEN,
+      ScannerErrorCode.EXPECTED_TOKEN,
+    ]);
+  }
+
   void test_lineInfo_multilineComment() {
     String source = "/*\r\n *\r\n */";
     _assertLineInfo(source, [
       new ScannerTest_ExpectedLocation(0, 1, 1),
       new ScannerTest_ExpectedLocation(5, 2, 2),
       new ScannerTest_ExpectedLocation(source.length - 1, 3, 3)
     ]);
   }
 
   void test_lineInfo_multilineString() {
@@ skipping 148 matching lines @@
     buffer.write(token.type);
     buffer.write(", '");
     buffer.write(token.lexeme);
     buffer.write("', ");
     buffer.write(token.offset);
     buffer.write(", ");
     buffer.write(token.length);
     buffer.write("]");
   }
 }