From e01ced050c36477768f3ccd7de5932d91ec9b182 Mon Sep 17 00:00:00 2001
From: Tobeyyy <tobiasscholz2000@gmail.com>
Date: Fri, 20 Jan 2023 01:59:07 +0100
Subject: [PATCH] fix type checking of variables named "exports" (#52209)

---
 src/compiler/checker.ts                                  | 2 +-
 .../reference/typeCheckExportsVariable.errors.txt        | 8 ++++++++
 tests/baselines/reference/typeCheckExportsVariable.js    | 7 +++++++
 .../baselines/reference/typeCheckExportsVariable.symbols | 7 +++++++
 tests/baselines/reference/typeCheckExportsVariable.types | 9 +++++++++
 tests/cases/compiler/typeCheckExportsVariable.ts         | 3 +++
 6 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/typeCheckExportsVariable.errors.txt
 create mode 100644 tests/baselines/reference/typeCheckExportsVariable.js
 create mode 100644 tests/baselines/reference/typeCheckExportsVariable.symbols
 create mode 100644 tests/baselines/reference/typeCheckExportsVariable.types
 create mode 100644 tests/cases/compiler/typeCheckExportsVariable.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d9df6a14dc0..e6ea8924e85 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -36500,7 +36500,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 if (checkReferenceExpression(left,
                     Diagnostics.The_left_hand_side_of_an_assignment_expression_must_be_a_variable_or_a_property_access,
                     Diagnostics.The_left_hand_side_of_an_assignment_expression_may_not_be_an_optional_property_access)
-                    && (!isIdentifier(left) || unescapeLeadingUnderscores(left.escapedText) !== "exports")) {
+                    ) {
 
                     let headMessage: DiagnosticMessage | undefined;
                     if (exactOptionalPropertyTypes && isPropertyAccessExpression(left) && maybeTypeOfKind(valueType, TypeFlags.Undefined)) {
diff --git a/tests/baselines/reference/typeCheckExportsVariable.errors.txt b/tests/baselines/reference/typeCheckExportsVariable.errors.txt
new file mode 100644
index 00000000000..9f0f04cf365
--- /dev/null
+++ b/tests/baselines/reference/typeCheckExportsVariable.errors.txt
@@ -0,0 +1,8 @@
+tests/cases/compiler/typeCheckExportsVariable.ts(2,1): error TS2322: Type 'string' is not assignable to type 'number'.
+
+
+==== tests/cases/compiler/typeCheckExportsVariable.ts (1 errors) ====
+    let exports: number;
+    exports = '';
+    ~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
\ No newline at end of file
diff --git a/tests/baselines/reference/typeCheckExportsVariable.js b/tests/baselines/reference/typeCheckExportsVariable.js
new file mode 100644
index 00000000000..616b0ff65e4
--- /dev/null
+++ b/tests/baselines/reference/typeCheckExportsVariable.js
@@ -0,0 +1,7 @@
+//// [typeCheckExportsVariable.ts]
+let exports: number;
+exports = '';
+
+//// [typeCheckExportsVariable.js]
+var exports;
+exports = '';
diff --git a/tests/baselines/reference/typeCheckExportsVariable.symbols b/tests/baselines/reference/typeCheckExportsVariable.symbols
new file mode 100644
index 00000000000..d7f4b0b8cbd
--- /dev/null
+++ b/tests/baselines/reference/typeCheckExportsVariable.symbols
@@ -0,0 +1,7 @@
+=== tests/cases/compiler/typeCheckExportsVariable.ts ===
+let exports: number;
+>exports : Symbol(exports, Decl(typeCheckExportsVariable.ts, 0, 3))
+
+exports = '';
+>exports : Symbol(exports, Decl(typeCheckExportsVariable.ts, 0, 3))
+
diff --git a/tests/baselines/reference/typeCheckExportsVariable.types b/tests/baselines/reference/typeCheckExportsVariable.types
new file mode 100644
index 00000000000..61cedca43c4
--- /dev/null
+++ b/tests/baselines/reference/typeCheckExportsVariable.types
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/typeCheckExportsVariable.ts ===
+let exports: number;
+>exports : number
+
+exports = '';
+>exports = '' : ""
+>exports : number
+>'' : ""
+
diff --git a/tests/cases/compiler/typeCheckExportsVariable.ts b/tests/cases/compiler/typeCheckExportsVariable.ts
new file mode 100644
index 00000000000..f3b4df3ee3b
--- /dev/null
+++ b/tests/cases/compiler/typeCheckExportsVariable.ts
@@ -0,0 +1,3 @@
+
+let exports: number;
+exports = '';
\ No newline at end of file