From 3050c62251b9a4cba3c005cd0dae6b91bcf39a8f Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Sun, 28 Apr 2019 13:58:58 -0700
Subject: [PATCH] Add regression test

---
 .../cases/conformance/types/keyof/keyofAndIndexedAccess2.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts b/tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts
index 356e0a42ae9b4..2794ec66dd4d5 100644
--- a/tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts
+++ b/tests/cases/conformance/types/keyof/keyofAndIndexedAccess2.ts
@@ -127,3 +127,9 @@ function fn<T extends {elements: Array<string>} | {elements: Array<number>}>(par
 function fn2<T extends Array<string>>(param: T, cb: (element: T[number]) => void) {
     cb(param[0]);
 }
+
+// Repro from #31149
+
+function fn3<T extends ReadonlyArray<string>>(param: T, cb: (element: T[number]) => void) {
+    cb(param[0]); // Argument of type 'string' is not assignable to parameter of type 'T[number]'.
+}