Tweak isValidHeritageClauseObjectLiteral

src/compiler/parser.ts

@@ -2880,7 +2880,7 @@ namespace Parser {
             case ParsingContext.ImportAttributes:
                 return isImportAttributeName();
             case ParsingContext.HeritageClauseElement:
-                // If we see `{ ... }` then only consume it as an expression if it is followed by `,` or `{`
+                // If we see `{ ... }` then only consume it as an expression if it is followed by `,`, `.`, `!`, `{`, `extends` or `implements`.
                 // That way we won't consume the body of a class in its heritage clause.
                 if (token() === SyntaxKind.OpenBraceToken) {
                     return lookAhead(isValidHeritageClauseObjectLiteral);
@@ -2946,15 +2946,17 @@ namespace Parser {
         Debug.assert(token() === SyntaxKind.OpenBraceToken);
         if (nextToken() === SyntaxKind.CloseBraceToken) {
             // if we see "extends {}" then only treat the {} as what we're extending (and not
-            // the class body) if we have:
-            //
-            //      extends {} {
-            //      extends {},
-            //      extends {} extends
-            //      extends {} implements
-
-            const next = nextToken();
-            return next === SyntaxKind.CommaToken || next === SyntaxKind.OpenBraceToken || next === SyntaxKind.ExtendsKeyword || next === SyntaxKind.ImplementsKeyword;
+            // the class body) if we have one of those next tokens.
+            switch (nextToken()) {
+                case SyntaxKind.CommaToken:
+                case SyntaxKind.DotToken:
+                case SyntaxKind.ExclamationToken:
+                case SyntaxKind.ExtendsKeyword:
+                case SyntaxKind.ImplementsKeyword:
+                case SyntaxKind.OpenBraceToken:
+                    return true;
+            }
+            return false;
         }
 
         return true;

tests/baselines/reference/parseHeritageClauseEmptyObject1.errors.txt

@@ -0,0 +1,50 @@
+parseHeritageClauseEmptyObject1_1.ts(1,18): error TS2507: Type '{}' is not a constructor function type.
+parseHeritageClauseEmptyObject1_1.ts(1,32): error TS2304: Cannot find name 'X'.
+parseHeritageClauseEmptyObject1_2.ts(1,18): error TS2507: Type '{}' is not a constructor function type.
+parseHeritageClauseEmptyObject1_2.ts(1,21): error TS1172: 'extends' clause already seen.
+parseHeritageClauseEmptyObject1_3.ts(1,18): error TS2507: Type '{}' is not a constructor function type.
+parseHeritageClauseEmptyObject1_3.ts(1,20): error TS1009: Trailing comma not allowed.
+parseHeritageClauseEmptyObject1_4.ts(1,18): error TS2507: Type '{}' is not a constructor function type.
+parseHeritageClauseEmptyObject1_5.ts(1,21): error TS2339: Property 'Foo' does not exist on type '{}'.
+parseHeritageClauseEmptyObject1_6.ts(1,21): error TS2339: Property 'Foo' does not exist on type '{}'.
+parseHeritageClauseEmptyObject1_6.ts(1,24): error TS1005: '{' expected.
+parseHeritageClauseEmptyObject1_7.ts(1,17): error TS1097: 'extends' list cannot be empty.
+
+
+==== parseHeritageClauseEmptyObject1_1.ts (2 errors) ====
+    class C1 extends {} implements X {}
+                     ~~
+!!! error TS2507: Type '{}' is not a constructor function type.
+                                   ~
+!!! error TS2304: Cannot find name 'X'.
+==== parseHeritageClauseEmptyObject1_2.ts (2 errors) ====
+    class C2 extends {} extends X {}
+                     ~~
+!!! error TS2507: Type '{}' is not a constructor function type.
+                        ~~~~~~~
+!!! error TS1172: 'extends' clause already seen.
+==== parseHeritageClauseEmptyObject1_3.ts (2 errors) ====
+    class C3 extends {}, {}
+                     ~~
+!!! error TS2507: Type '{}' is not a constructor function type.
+                       ~
+!!! error TS1009: Trailing comma not allowed.
+==== parseHeritageClauseEmptyObject1_4.ts (1 errors) ====
+    class C4 extends {}! {}
+                     ~~~
+!!! error TS2507: Type '{}' is not a constructor function type.
+==== parseHeritageClauseEmptyObject1_5.ts (1 errors) ====
+    class C5 extends {}.Foo {}
+                        ~~~
+!!! error TS2339: Property 'Foo' does not exist on type '{}'.
+==== parseHeritageClauseEmptyObject1_6.ts (2 errors) ====
+    class C6 extends {}.Foo
+                        ~~~
+!!! error TS2339: Property 'Foo' does not exist on type '{}'.
+
+!!! error TS1005: '{' expected.
+==== parseHeritageClauseEmptyObject1_7.ts (1 errors) ====
+    class C7 extends {}
+
+!!! error TS1097: 'extends' list cannot be empty.
+

tests/baselines/reference/parseHeritageClauseEmptyObject1.js

@@ -0,0 +1,46 @@
+//// [tests/cases/compiler/parseHeritageClauseEmptyObject1.ts] ////
+
+//// [parseHeritageClauseEmptyObject1_1.ts]
+class C1 extends {} implements X {}
+//// [parseHeritageClauseEmptyObject1_2.ts]
+class C2 extends {} extends X {}
+//// [parseHeritageClauseEmptyObject1_3.ts]
+class C3 extends {}, {}
+//// [parseHeritageClauseEmptyObject1_4.ts]
+class C4 extends {}! {}
+//// [parseHeritageClauseEmptyObject1_5.ts]
+class C5 extends {}.Foo {}
+//// [parseHeritageClauseEmptyObject1_6.ts]
+class C6 extends {}.Foo
+//// [parseHeritageClauseEmptyObject1_7.ts]
+class C7 extends {}
+
+
+//// [parseHeritageClauseEmptyObject1_1.js]
+"use strict";
+class C1 extends {} {
+}
+//// [parseHeritageClauseEmptyObject1_2.js]
+"use strict";
+class C2 extends {} extends X {
+}
+//// [parseHeritageClauseEmptyObject1_3.js]
+"use strict";
+class C3 extends {} {
+}
+//// [parseHeritageClauseEmptyObject1_4.js]
+"use strict";
+class C4 extends {} {
+}
+//// [parseHeritageClauseEmptyObject1_5.js]
+"use strict";
+class C5 extends {}.Foo {
+}
+//// [parseHeritageClauseEmptyObject1_6.js]
+"use strict";
+class C6 extends {}.Foo {
+}
+//// [parseHeritageClauseEmptyObject1_7.js]
+"use strict";
+class C7 extends  {
+}

tests/baselines/reference/parseHeritageClauseEmptyObject1.symbols

@@ -0,0 +1,30 @@
+//// [tests/cases/compiler/parseHeritageClauseEmptyObject1.ts] ////
+
+=== parseHeritageClauseEmptyObject1_1.ts ===
+class C1 extends {} implements X {}
+>C1 : Symbol(C1, Decl(parseHeritageClauseEmptyObject1_1.ts, 0, 0))
+
+=== parseHeritageClauseEmptyObject1_2.ts ===
+class C2 extends {} extends X {}
+>C2 : Symbol(C2, Decl(parseHeritageClauseEmptyObject1_2.ts, 0, 0))
+
+=== parseHeritageClauseEmptyObject1_3.ts ===
+class C3 extends {}, {}
+>C3 : Symbol(C3, Decl(parseHeritageClauseEmptyObject1_3.ts, 0, 0))
+
+=== parseHeritageClauseEmptyObject1_4.ts ===
+class C4 extends {}! {}
+>C4 : Symbol(C4, Decl(parseHeritageClauseEmptyObject1_4.ts, 0, 0))
+
+=== parseHeritageClauseEmptyObject1_5.ts ===
+class C5 extends {}.Foo {}
+>C5 : Symbol(C5, Decl(parseHeritageClauseEmptyObject1_5.ts, 0, 0))
+
+=== parseHeritageClauseEmptyObject1_6.ts ===
+class C6 extends {}.Foo
+>C6 : Symbol(C6, Decl(parseHeritageClauseEmptyObject1_6.ts, 0, 0))
+
+=== parseHeritageClauseEmptyObject1_7.ts ===
+class C7 extends {}
+>C7 : Symbol(C7, Decl(parseHeritageClauseEmptyObject1_7.ts, 0, 0))
+

tests/baselines/reference/parseHeritageClauseEmptyObject1.types

@@ -0,0 +1,61 @@
+//// [tests/cases/compiler/parseHeritageClauseEmptyObject1.ts] ////
+
+=== parseHeritageClauseEmptyObject1_1.ts ===
+class C1 extends {} implements X {}
+>C1 : C1
+>   : ^^
+>{} : {}
+>   : ^^
+
+=== parseHeritageClauseEmptyObject1_2.ts ===
+class C2 extends {} extends X {}
+>C2 : C2
+>   : ^^
+>{} : {}
+>   : ^^
+>X : any
+>  : ^^^
+
+=== parseHeritageClauseEmptyObject1_3.ts ===
+class C3 extends {}, {}
+>C3 : C3
+>   : ^^
+>{} : {}
+>   : ^^
+
+=== parseHeritageClauseEmptyObject1_4.ts ===
+class C4 extends {}! {}
+>C4 : C4
+>   : ^^
+>{}! : {}
+>    : ^^
+>{} : {}
+>   : ^^
+
+=== parseHeritageClauseEmptyObject1_5.ts ===
+class C5 extends {}.Foo {}
+>C5 : C5
+>   : ^^
+>{}.Foo : any
+>       : ^^^
+>{} : {}
+>   : ^^
+>Foo : any
+>    : ^^^
+
+=== parseHeritageClauseEmptyObject1_6.ts ===
+class C6 extends {}.Foo
+>C6 : C6
+>   : ^^
+>{}.Foo : any
+>       : ^^^
+>{} : {}
+>   : ^^
+>Foo : any
+>    : ^^^
+
+=== parseHeritageClauseEmptyObject1_7.ts ===
+class C7 extends {}
+>C7 : C7
+>   : ^^
+

tests/cases/compiler/parseHeritageClauseEmptyObject1.ts

@@ -0,0 +1,17 @@
+// @strict: true
+// @target: esnext
+
+// @filename: parseHeritageClauseEmptyObject1_1.ts
+class C1 extends {} implements X {}
+// @filename: parseHeritageClauseEmptyObject1_2.ts
+class C2 extends {} extends X {}
+// @filename: parseHeritageClauseEmptyObject1_3.ts
+class C3 extends {}, {}
+// @filename: parseHeritageClauseEmptyObject1_4.ts
+class C4 extends {}! {}
+// @filename: parseHeritageClauseEmptyObject1_5.ts
+class C5 extends {}.Foo {}
+// @filename: parseHeritageClauseEmptyObject1_6.ts
+class C6 extends {}.Foo
+// @filename: parseHeritageClauseEmptyObject1_7.ts
+class C7 extends {}