From 2ba9ff19c841c8f9fc6ebc361464a10a9008f529 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Burzy=C5=84ski?= <mateuszburzynski@gmail.com>
Date: Wed, 31 Aug 2022 07:50:47 +0200
Subject: [PATCH] Only check if the index type should be deferred for
 intersection types

---
 src/compiler/checker.ts | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 70daadb0923..f10e4f92e04 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -15903,13 +15903,10 @@ namespace ts {
         }
 
         function distributeIndexOverObjectType(objectType: Type, indexType: Type, writing: boolean) {
-            if (shouldDeferIndexType(objectType)) {
-                return;
-            }
             // (T | U)[K] -> T[K] | U[K] (reading)
             // (T | U)[K] -> T[K] & U[K] (writing)
             // (T & U)[K] -> T[K] & U[K]
-            if (objectType.flags & TypeFlags.UnionOrIntersection) {
+            if (objectType.flags & TypeFlags.Union || objectType.flags & TypeFlags.Intersection && !shouldDeferIndexType(objectType)) {
                 const types = map((objectType as UnionOrIntersectionType).types, t => getSimplifiedType(getIndexedAccessType(t, indexType), writing));
                 return objectType.flags & TypeFlags.Intersection || writing ? getIntersectionType(types) : getUnionType(types);
             }