add rescan question question token to fix regression

Kingwl · Kingwl · commit 2327b3b4d308 · 2019-08-15T13:57:58.000+08:00
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
@@ -2953,6 +2953,10 @@ namespace ts {
                     return parseJSDocAllType(/*postfixEquals*/ false);
                 case SyntaxKind.AsteriskEqualsToken:
                     return parseJSDocAllType(/*postfixEquals*/ true);
+                case SyntaxKind.QuestionQuestionToken:
+                    // If there is '??', consider that is prefix '?' in JSDoc type.
+                    scanner.reScanQuestionQuestionToken();
+                    // falls through
                 case SyntaxKind.QuestionToken:
                     return parseJSDocUnknownOrNullableType();
                 case SyntaxKind.FunctionKeyword:
diff --git a/src/compiler/scanner.ts b/src/compiler/scanner.ts
@@ -32,6 +32,7 @@ namespace ts {
         scanJsxAttributeValue(): SyntaxKind;
         reScanJsxToken(): JsxTokenSyntaxKind;
         reScanLessThanToken(): SyntaxKind;
+        reScanQuestionQuestionToken(): SyntaxKind;
         scanJsxToken(): JsxTokenSyntaxKind;
         scanJsDocToken(): JSDocSyntaxKind;
         scan(): SyntaxKind;
@@ -886,6 +887,7 @@ namespace ts {
             scanJsxAttributeValue,
             reScanJsxToken,
             reScanLessThanToken,
+            reScanQuestionQuestionToken,
             scanJsxToken,
             scanJsDocToken,
             scan,
@@ -1962,6 +1964,12 @@ namespace ts {
             return token;
         }
 
+        function reScanQuestionQuestionToken(): SyntaxKind {
+            Debug.assert(token === SyntaxKind.QuestionQuestionToken, "'reScanQuestionQuestionToken' should only be called on a '??'");
+            pos = tokenPos + 1;
+            return token = SyntaxKind.QuestionToken;
+        }
+
         function scanJsxToken(): JsxTokenSyntaxKind {
             startPos = tokenPos = pos;
 
