From d96d16e10b1c307719314886a2a740735593a2e8 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Sat, 20 Jul 2019 10:01:59 -0700
Subject: [PATCH] Add additional test

---
 .../typeInference/unionTypeInference.ts               | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tests/cases/conformance/types/typeRelationships/typeInference/unionTypeInference.ts b/tests/cases/conformance/types/typeRelationships/typeInference/unionTypeInference.ts
index ccedb753354..4d9a3eae21e 100644
--- a/tests/cases/conformance/types/typeRelationships/typeInference/unionTypeInference.ts
+++ b/tests/cases/conformance/types/typeRelationships/typeInference/unionTypeInference.ts
@@ -32,6 +32,17 @@ const d1 = f4("abc");
 const d2 = f4(s);
 const d3 = f4(42);  // Error
 
+export interface Foo<T> {
+    then<U>(f: (x: T) => U | Foo<U>, g: U): Foo<U>;
+}
+export interface Bar<T> {
+    then<S>(f: (x: T) => S | Bar<S>, g: S): Bar<S>;
+}
+
+function qux(p1: Foo<void>, p2: Bar<void>) {
+    p1 = p2;
+}
+
 // Repros from #32434
 
 declare function foo<T>(x: T | Promise<T>): void;