From e44a52a0110472b64c7c57533bbbd99e2a6ecd04 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 11 Apr 2019 16:22:01 -1000
Subject: [PATCH] Add regression test

---
 tests/cases/compiler/conditionalTypeSimplification.ts | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 tests/cases/compiler/conditionalTypeSimplification.ts

diff --git a/tests/cases/compiler/conditionalTypeSimplification.ts b/tests/cases/compiler/conditionalTypeSimplification.ts
new file mode 100644
index 00000000000..74c4d950451
--- /dev/null
+++ b/tests/cases/compiler/conditionalTypeSimplification.ts
@@ -0,0 +1,10 @@
+// Repro from #30794
+
+interface AbstractSchema<S, V> {
+  m1<T> (v: T): SchemaType<S, Exclude<V, T>>;
+  m2<T> (v: T): SchemaType<S, T>;
+}
+
+type SchemaType<S, V> = S extends object ? AnySchema<V> : never;
+interface AnySchema<V> extends AnySchemaType<AnySchema<undefined>, V> { }
+interface AnySchemaType<S extends AbstractSchema<any, any>, V> extends AbstractSchema<S, V> { }