From 4bb5cfb9bb1b371c09b08b151bb50522537726b9 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Tue, 25 Sep 2018 18:17:21 -0700
Subject: [PATCH] Add regression test

---
 .../typeInference/bivariantInferences.ts             | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 tests/cases/conformance/types/typeRelationships/typeInference/bivariantInferences.ts

diff --git a/tests/cases/conformance/types/typeRelationships/typeInference/bivariantInferences.ts b/tests/cases/conformance/types/typeRelationships/typeInference/bivariantInferences.ts
new file mode 100644
index 00000000000..c0e2ee497d0
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/typeInference/bivariantInferences.ts
@@ -0,0 +1,12 @@
+// @strict: true
+
+// Repro from #27337
+
+interface Array<T> {
+    equalsShallow<T>(this: ReadonlyArray<T>, other: ReadonlyArray<T>): boolean;
+}
+
+declare const a: (string | number)[] | null[] | undefined[] | {}[];
+declare const b: (string | number)[] | null[] | undefined[] | {}[];
+
+let x = a.equalsShallow(b);