update analyzer parser tests for fasta scanner

pkg/analyzer/lib/src/generated/parser.dart

Index: pkg/analyzer/lib/src/generated/parser.dart
diff --git a/pkg/analyzer/lib/src/generated/parser.dart b/pkg/analyzer/lib/src/generated/parser.dart
index 92b5d0ea179525758bf4e485afcdb9bb9cc7b4d8..e7187a2463d8a603b8a54dbe5c3b255604f99916 100644
--- a/pkg/analyzer/lib/src/generated/parser.dart
+++ b/pkg/analyzer/lib/src/generated/parser.dart
@@ -1275,7 +1275,8 @@ class Parser {
         _validateModifiersForGetterOrSetterOrMethod(modifiers);
         return parseSetter(commentAndMetadata, modifiers.externalKeyword,
             modifiers.staticKeyword, returnType);
-      } else if (keyword == Keyword.OPERATOR && _isOperator(next)) {
+      } else if (keyword == Keyword.OPERATOR &&
+          (_isOperator(next) || next.type == TokenType.EQ_EQ_EQ)) {

[Brian Wilkerson, 2017/06/06 14:00:17]

What is "==="?

That operator hasn't been part of the language for a long time, so I'm guessing
that this is here for recovery. But is there any reason to think that there's
value in supporting this kind of recovery? There have not been any issues that
I'm aware of where people were confused by its absence. I think it would be
better to keep the code cleaner rather than add recovery for a rare case.

If we really think this is useful, then we should document (in the fasta parser,
presumably) that this support is here for recovery purposes.

[danrubel, 2017/06/07 15:03:46]

Good question. It exists for the purpose of better recovery. I'll add docs for
the token indicating as much.

         _validateModifiersForOperator(modifiers);
         return _parseOperatorAfterKeyword(commentAndMetadata,
             modifiers.externalKeyword, returnType, getAndAdvance());
@@ -7209,7 +7210,10 @@ class Parser {
       Token operatorKeyword) {
     if (!_currentToken.isUserDefinableOperator) {
       _reportErrorForCurrentToken(
-          ParserErrorCode.NON_USER_DEFINABLE_OPERATOR, [_currentToken.lexeme]);
+          _currentToken.type == TokenType.EQ_EQ_EQ
+              ? ParserErrorCode.INVALID_OPERATOR
+              : ParserErrorCode.NON_USER_DEFINABLE_OPERATOR,
+          [_currentToken.lexeme]);
     }
     SimpleIdentifier name =
         astFactory.simpleIdentifier(getAndAdvance(), isDeclaration: true);