Make (): unambiguous again

microsoft · Apr 20, 2022 · fb6ba84 · fb6ba84
1 parent f5ecb51
commit fb6ba84
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Showing 4 changed files with 9 additions and 18 deletions.
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
@@ -4452,7 +4452,7 @@ namespace ts {
         }
 
         function tryParseParenthesizedArrowFunctionExpression(disallowReturnTypeInArrowFunction: boolean): Expression | undefined {
-            const triState = isParenthesizedArrowFunctionExpression(disallowReturnTypeInArrowFunction);
+            const triState = isParenthesizedArrowFunctionExpression();
             if (triState === Tristate.False) {
                 // It's definitely not a parenthesized arrow function expression.
                 return undefined;
@@ -4471,9 +4471,9 @@ namespace ts {
         //  False       -> There *cannot* be a parenthesized arrow function here.
         //  Unknown     -> There *might* be a parenthesized arrow function here.
         //                 Speculatively look ahead to be sure, and rollback if not.
-        function isParenthesizedArrowFunctionExpression(disallowReturnTypeInArrowFunction: boolean): Tristate {
+        function isParenthesizedArrowFunctionExpression(): Tristate {
             if (token() === SyntaxKind.OpenParenToken || token() === SyntaxKind.LessThanToken || token() === SyntaxKind.AsyncKeyword) {
-                return lookAhead(() => isParenthesizedArrowFunctionExpressionWorker(disallowReturnTypeInArrowFunction));
+                return lookAhead(isParenthesizedArrowFunctionExpressionWorker);
             }
 
             if (token() === SyntaxKind.EqualsGreaterThanToken) {
@@ -4486,7 +4486,7 @@ namespace ts {
             return Tristate.False;
         }
 
-        function isParenthesizedArrowFunctionExpressionWorker(disallowReturnTypeInArrowFunction: boolean) {
+        function isParenthesizedArrowFunctionExpressionWorker() {
             if (token() === SyntaxKind.AsyncKeyword) {
                 nextToken();
                 if (scanner.hasPrecedingLineBreak()) {
@@ -4508,13 +4508,8 @@ namespace ts {
                     // but this is probably what the user intended.
                     const third = nextToken();
                     switch (third) {
-                        case SyntaxKind.ColonToken:
-                            if (disallowReturnTypeInArrowFunction) {
-                                // "a ? () : ..."
-                                return Tristate.False;
-                            }
-                            return Tristate.True;
                         case SyntaxKind.EqualsGreaterThanToken:
+                        case SyntaxKind.ColonToken:
                         case SyntaxKind.OpenBraceToken:
                             return Tristate.True;
                         default:

diff --git a/tests/baselines/reference/parserArrowFunctionExpression13.errors.txt b/tests/baselines/reference/parserArrowFunctionExpression13.errors.txt
@@ -1,17 +1,14 @@
 tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts(1,1): error TS2304: Cannot find name 'a'.
 tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts(1,11): error TS2304: Cannot find name 'a'.
-tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts(1,18): error TS1109: Expression expected.
-tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts(1,19): error TS1005: ';' expected.
+tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts(1,19): error TS1109: Expression expected.
 
 
-==== tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts (4 errors) ====
+==== tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression13.ts (3 errors) ====
     a ? () => a() : (): any => null;
     ~
 !!! error TS2304: Cannot find name 'a'.
               ~
 !!! error TS2304: Cannot find name 'a'.
-                     ~
-!!! error TS1109: Expression expected.
                       ~
-!!! error TS1005: ';' expected.
+!!! error TS1109: Expression expected.
 
diff --git a/tests/baselines/reference/parserArrowFunctionExpression13.js b/tests/baselines/reference/parserArrowFunctionExpression13.js
@@ -3,5 +3,5 @@ a ? () => a() : (): any => null;
 
 
 //// [parserArrowFunctionExpression13.js]
-a ? function () { return a(); } : ();
+a ? function () { return a(); } : ;
 (function (any) { return null; });
diff --git a/tests/baselines/reference/parserArrowFunctionExpression13.types b/tests/baselines/reference/parserArrowFunctionExpression13.types
@@ -5,7 +5,6 @@ a ? () => a() : (): any => null;
 >() => a() : () => any
 >a() : any
 >a : any
->() : any
 > : any
 >any => null : (any: any) => any
 >any : any