From 3531bd2b570d0ca95276fd78fd8e6217a90c3b4b Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Fri, 1 Dec 2017 16:54:32 -0800
Subject: [PATCH] Add regression test

---
 .../functionCallOnConstrainedTypeVariable.ts  | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 tests/cases/compiler/functionCallOnConstrainedTypeVariable.ts

diff --git a/tests/cases/compiler/functionCallOnConstrainedTypeVariable.ts b/tests/cases/compiler/functionCallOnConstrainedTypeVariable.ts
new file mode 100644
index 0000000000..8ceb578dc0
--- /dev/null
+++ b/tests/cases/compiler/functionCallOnConstrainedTypeVariable.ts
@@ -0,0 +1,22 @@
+// @strict: true
+
+// Repro from #20196
+
+type A = {
+  a: (x: number) => string
+};
+type B = {
+  a: (x: boolean) => string
+};
+
+function call0(p: A | B) { 
+  p.a("s"); // Error
+}
+
+function callN<T extends A | B>(p: T) {
+  p.a("s"); // Error
+  
+  var a: T["a"] = p.a;
+  a(""); // Error
+  a("", "", "", ""); // Error
+}
\ No newline at end of file