From 2150a64f0cd457a791ac30c8850934cd6ee35704 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Tue, 11 Dec 2018 12:11:16 -0800
Subject: [PATCH] Add tests

---
 .../types/keyof/keyofAndIndexedAccessErrors.ts   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts b/tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts
index a4ed608d8e7..a179935d0ec 100644
--- a/tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts
+++ b/tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts
@@ -141,3 +141,19 @@ function test1<T extends Record<string, any>, K extends keyof T>(t: T, k: K) {
     t[k] = "hello";  // Error
     t[k] = [10, 20];  // Error
 }
+
+// Repro from #28839
+
+function f30<T, K extends keyof T>() {
+    let x: Partial<Record<keyof T, string>>[K] = "hello";
+}
+
+// We simplify indexed accesses applied to mapped types up to five levels deep
+
+function f31<T, K extends keyof T>() {
+    let x: Partial<Partial<Partial<Partial<Record<keyof T, string>>>>>[K] = "hello";
+}
+
+function f32<T, K extends keyof T>() {
+    let x: Partial<Partial<Partial<Partial<Partial<Record<keyof T, string>>>>>>[K] = "hello";
+}