From 46cd4219ddbf243c34088bc0682f7f1da5a4b261 Mon Sep 17 00:00:00 2001
From: bgenia <xbgenia@gmail.com>
Date: Sun, 17 Nov 2024 15:04:30 +0300
Subject: [PATCH] Remove getNonNullableType application in checkIdentifier

---
 src/compiler/checker.ts                            |  3 +--
 .../wrongEvolvingTypeUnderNonNullAssertion.ts      | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 tests/cases/fourslash/wrongEvolvingTypeUnderNonNullAssertion.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index cc8a7f7428f..0b91bfd9c44 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -30525,8 +30525,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         const initialType = isAutomaticTypeInNonNull ? undefinedType :
             assumeInitialized ? (isParameter ? removeOptionalityFromDeclaredType(type, declaration as VariableLikeDeclaration) : type) :
             typeIsAutomatic ? undefinedType : getOptionalType(type);
-        const flowType = isAutomaticTypeInNonNull ? getNonNullableType(getFlowTypeOfReference(node, type, initialType, flowContainer)) :
-            getFlowTypeOfReference(node, type, initialType, flowContainer);
+        const flowType = getFlowTypeOfReference(node, type, initialType, flowContainer);
         // A variable is considered uninitialized when it is possible to analyze the entire control flow graph
         // from declaration to use, and when the variable's declared type doesn't include undefined but the
         // control flow based type does include undefined.
diff --git a/tests/cases/fourslash/wrongEvolvingTypeUnderNonNullAssertion.ts b/tests/cases/fourslash/wrongEvolvingTypeUnderNonNullAssertion.ts
new file mode 100644
index 00000000000..86846551f76
--- /dev/null
+++ b/tests/cases/fourslash/wrongEvolvingTypeUnderNonNullAssertion.ts
@@ -0,0 +1,14 @@
+/// <reference path="fourslash.ts" />
+
+// Issue #60514
+
+// @strict: true
+//// declare function foo(): number | undefined
+//// let x;
+//// x = foo();
+//// let [|y2|] = [|x|]!;
+
+const [afterAssertion, beforeAssertion] = test.ranges()
+
+verify.typeAtLocation(beforeAssertion, "number | undefined")
+verify.typeAtLocation(afterAssertion, "number")