From 316f0ab7f9fd2cf79ddaf2264d3a629c5d433c43 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Wed, 6 Nov 2024 11:43:12 -0800
Subject: [PATCH] MetaProperty is possibly nullish

Fixes #60439
---
 src/compiler/checker.ts                       |  1 +
 .../reference/predicateSemantics.errors.txt   |  7 +++++++
 .../baselines/reference/predicateSemantics.js | 16 +++++++++++++++
 .../reference/predicateSemantics.symbols      | 12 +++++++++++
 .../reference/predicateSemantics.types        | 20 +++++++++++++++++++
 tests/cases/compiler/predicateSemantics.ts    |  7 +++++++
 6 files changed, 63 insertions(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d1d09f32dd8cd..735d42fefa706 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -39755,6 +39755,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             case SyntaxKind.AwaitExpression:
             case SyntaxKind.CallExpression:
             case SyntaxKind.ElementAccessExpression:
+            case SyntaxKind.MetaProperty:
             case SyntaxKind.NewExpression:
             case SyntaxKind.PropertyAccessExpression:
             case SyntaxKind.YieldExpression:
diff --git a/tests/baselines/reference/predicateSemantics.errors.txt b/tests/baselines/reference/predicateSemantics.errors.txt
index 1c9de704f1628..0dc25d43dbf2b 100644
--- a/tests/baselines/reference/predicateSemantics.errors.txt
+++ b/tests/baselines/reference/predicateSemantics.errors.txt
@@ -96,4 +96,11 @@ predicateSemantics.ts(52,14): error TS2869: Right operand of ?? is unreachable b
                  ~~~~~~~~~~
 !!! error TS2869: Right operand of ?? is unreachable because the left operand is never nullish.
     }
+    
+    // https://github.com/microsoft/TypeScript/issues/60439
+    class X {
+      constructor() {
+        const p = new.target ?? 32;
+      }
+    }
     
\ No newline at end of file
diff --git a/tests/baselines/reference/predicateSemantics.js b/tests/baselines/reference/predicateSemantics.js
index 3641305b71805..f4edc198ffecd 100644
--- a/tests/baselines/reference/predicateSemantics.js
+++ b/tests/baselines/reference/predicateSemantics.js
@@ -54,6 +54,13 @@ function foo(this: Object | undefined) {
   const e = (i++, i++) ?? true; // error
   const f = (maybe, i++) ?? true; // error
 }
+
+// https://github.com/microsoft/TypeScript/issues/60439
+class X {
+  constructor() {
+    const p = new.target ?? 32;
+  }
+}
 
 
 //// [predicateSemantics.js]
@@ -106,3 +113,12 @@ function foo() {
     var e = (_h = (i++, i++)) !== null && _h !== void 0 ? _h : true; // error
     var f = (_j = (maybe, i++)) !== null && _j !== void 0 ? _j : true; // error
 }
+// https://github.com/microsoft/TypeScript/issues/60439
+var X = /** @class */ (function () {
+    function X() {
+        var _newTarget = this.constructor;
+        var _a;
+        var p = (_a = _newTarget) !== null && _a !== void 0 ? _a : 32;
+    }
+    return X;
+}());
diff --git a/tests/baselines/reference/predicateSemantics.symbols b/tests/baselines/reference/predicateSemantics.symbols
index c91201e3fcda2..e5c831515a0bc 100644
--- a/tests/baselines/reference/predicateSemantics.symbols
+++ b/tests/baselines/reference/predicateSemantics.symbols
@@ -104,3 +104,15 @@ function foo(this: Object | undefined) {
 >i : Symbol(i, Decl(predicateSemantics.ts, 48, 5))
 }
 
+// https://github.com/microsoft/TypeScript/issues/60439
+class X {
+>X : Symbol(X, Decl(predicateSemantics.ts, 52, 1))
+
+  constructor() {
+    const p = new.target ?? 32;
+>p : Symbol(p, Decl(predicateSemantics.ts, 57, 9))
+>new.target : Symbol(X, Decl(predicateSemantics.ts, 52, 1))
+>target : Symbol(X, Decl(predicateSemantics.ts, 52, 1))
+  }
+}
+
diff --git a/tests/baselines/reference/predicateSemantics.types b/tests/baselines/reference/predicateSemantics.types
index ee88a95cd16ea..de0c9daf76eb0 100644
--- a/tests/baselines/reference/predicateSemantics.types
+++ b/tests/baselines/reference/predicateSemantics.types
@@ -308,3 +308,23 @@ function foo(this: Object | undefined) {
 >     : ^^^^
 }
 
+// https://github.com/microsoft/TypeScript/issues/60439
+class X {
+>X : X
+>  : ^
+
+  constructor() {
+    const p = new.target ?? 32;
+>p : 32 | typeof X
+>  : ^^^^^^^^^^^^^
+>new.target ?? 32 : 32 | typeof X
+>                 : ^^^^^^^^^^^^^
+>new.target : typeof X
+>           : ^^^^^^^^
+>target : typeof X
+>       : ^^^^^^^^
+>32 : 32
+>   : ^^
+  }
+}
+
diff --git a/tests/cases/compiler/predicateSemantics.ts b/tests/cases/compiler/predicateSemantics.ts
index 88374b9a2ff6b..e937b1d6182a8 100644
--- a/tests/cases/compiler/predicateSemantics.ts
+++ b/tests/cases/compiler/predicateSemantics.ts
@@ -51,3 +51,10 @@ function foo(this: Object | undefined) {
   const e = (i++, i++) ?? true; // error
   const f = (maybe, i++) ?? true; // error
 }
+
+// https://github.com/microsoft/TypeScript/issues/60439
+class X {
+  constructor() {
+    const p = new.target ?? 32;
+  }
+}