From 21c7f1cbb81d7abbbef92ab769a2e68393986e01 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Fri, 15 Mar 2024 14:58:30 -0700
Subject: [PATCH] Remove nonNullUnknownType (#57665)

---
 src/compiler/checker.ts | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index c52ee477145..c8eefa77783 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -1968,7 +1968,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     var nonInferrableAnyType = createIntrinsicType(TypeFlags.Any, "any", ObjectFlags.ContainsWideningType, "non-inferrable");
     var intrinsicMarkerType = createIntrinsicType(TypeFlags.Any, "intrinsic");
     var unknownType = createIntrinsicType(TypeFlags.Unknown, "unknown");
-    var nonNullUnknownType = createIntrinsicType(TypeFlags.Unknown, "unknown", /*objectFlags*/ undefined, "non-null");
     var undefinedType = createIntrinsicType(TypeFlags.Undefined, "undefined");
     var undefinedWideningType = strictNullChecks ? undefinedType : createIntrinsicType(TypeFlags.Undefined, "undefined", ObjectFlags.ContainsWideningType, "widening");
     var missingType = createIntrinsicType(TypeFlags.Undefined, "undefined", /*objectFlags*/ undefined, "missing");
@@ -17293,7 +17292,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             if (includes & TypeFlags.AnyOrUnknown) {
                 return includes & TypeFlags.Any ?
                     includes & TypeFlags.IncludesWildcard ? wildcardType : anyType :
-                    includes & TypeFlags.Null || containsType(typeSet, unknownType) ? unknownType : nonNullUnknownType;
+                    unknownType;
             }
             if (includes & TypeFlags.Undefined) {
                 // If type set contains both undefinedType and missingType, remove missingType
@@ -27738,8 +27737,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         if (resultType === unreachableNeverType || reference.parent && reference.parent.kind === SyntaxKind.NonNullExpression && !(resultType.flags & TypeFlags.Never) && getTypeWithFacts(resultType, TypeFacts.NEUndefinedOrNull).flags & TypeFlags.Never) {
             return declaredType;
         }
-        // The non-null unknown type should never escape control flow analysis.
-        return resultType === nonNullUnknownType ? unknownType : resultType;
+        return resultType;
 
         function getOrSetCacheKey() {
             if (isKeySet) {