fix(48653): throw an error on an invalid optional chain from new expression (#48656)

src/compiler/diagnosticMessages.json

@@ -651,6 +651,10 @@
         "category": "Error",
         "code": 1208
     },
+    "Invalid optional chain from new expression. Did you mean to call '{0}()'?": {
+        "category": "Error",
+        "code": 1209
+    },
     "Code contained in a class is evaluated in JavaScript's strict mode which does not allow this use of '{0}'. For more information, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode.": {
         "category": "Error",
         "code": 1210

src/compiler/parser.ts

@@ -5942,6 +5942,9 @@ namespace ts {
                 typeArguments = (expression as ExpressionWithTypeArguments).typeArguments;
                 expression = (expression as ExpressionWithTypeArguments).expression;
             }
+            if (token() === SyntaxKind.QuestionDotToken) {
+                parseErrorAtCurrentToken(Diagnostics.Invalid_optional_chain_from_new_expression_Did_you_mean_to_call_0, getTextOfNodeFromSourceText(sourceText, expression));
+            }
             const argumentList = token() === SyntaxKind.OpenParenToken ? parseArgumentList() : undefined;
             return finishNode(factory.createNewExpression(expression, typeArguments, argumentList), pos);
         }

tests/baselines/reference/invalidOptionalChainFromNewExpression.errors.txt

@@ -0,0 +1,13 @@
+tests/cases/compiler/invalidOptionalChainFromNewExpression.ts(5,6): error TS1209: Invalid optional chain from new expression. Did you mean to call 'A()'?
+
+
+==== tests/cases/compiler/invalidOptionalChainFromNewExpression.ts (1 errors) ====
+    class A {
+        b() {}
+    }
+    
+    new A?.b()   // error
+         ~~
+!!! error TS1209: Invalid optional chain from new expression. Did you mean to call 'A()'?
+    new A()?.b() // ok
+    

tests/baselines/reference/invalidOptionalChainFromNewExpression.js

@@ -0,0 +1,19 @@
+//// [invalidOptionalChainFromNewExpression.ts]
+class A {
+    b() {}
+}
+
+new A?.b()   // error
+new A()?.b() // ok
+
+
+//// [invalidOptionalChainFromNewExpression.js]
+var _a, _b;
+var A = /** @class */ (function () {
+    function A() {
+    }
+    A.prototype.b = function () { };
+    return A;
+}());
+(_a = new A) === null || _a === void 0 ? void 0 : _a.b(); // error
+(_b = new A()) === null || _b === void 0 ? void 0 : _b.b(); // ok

tests/baselines/reference/invalidOptionalChainFromNewExpression.symbols

@@ -0,0 +1,18 @@
+=== tests/cases/compiler/invalidOptionalChainFromNewExpression.ts ===
+class A {
+>A : Symbol(A, Decl(invalidOptionalChainFromNewExpression.ts, 0, 0))
+
+    b() {}
+>b : Symbol(A.b, Decl(invalidOptionalChainFromNewExpression.ts, 0, 9))
+}
+
+new A?.b()   // error
+>new A?.b : Symbol(A.b, Decl(invalidOptionalChainFromNewExpression.ts, 0, 9))
+>A : Symbol(A, Decl(invalidOptionalChainFromNewExpression.ts, 0, 0))
+>b : Symbol(A.b, Decl(invalidOptionalChainFromNewExpression.ts, 0, 9))
+
+new A()?.b() // ok
+>new A()?.b : Symbol(A.b, Decl(invalidOptionalChainFromNewExpression.ts, 0, 9))
+>A : Symbol(A, Decl(invalidOptionalChainFromNewExpression.ts, 0, 0))
+>b : Symbol(A.b, Decl(invalidOptionalChainFromNewExpression.ts, 0, 9))
+

tests/baselines/reference/invalidOptionalChainFromNewExpression.types

@@ -0,0 +1,22 @@
+=== tests/cases/compiler/invalidOptionalChainFromNewExpression.ts ===
+class A {
+>A : A
+
+    b() {}
+>b : () => void
+}
+
+new A?.b()   // error
+>new A?.b() : void
+>new A?.b : () => void
+>new A : A
+>A : typeof A
+>b : () => void
+
+new A()?.b() // ok
+>new A()?.b() : void
+>new A()?.b : () => void
+>new A() : A
+>A : typeof A
+>b : () => void
+

tests/cases/compiler/invalidOptionalChainFromNewExpression.ts

@@ -0,0 +1,6 @@
+class A {
+    b() {}
+}
+
+new A?.b()   // error
+new A()?.b() // ok