From 67b4b9076d64e69d85441f7d6f723e86374e62f7 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <Daniel.Rosenwasser@microsoft.com>
Date: Thu, 8 Oct 2020 16:43:00 -0700
Subject: [PATCH] Add test case for 'useUnknownInCatchVariables'.

---
 .../compiler/useUnknownInCatchVariables01.ts  | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 tests/cases/compiler/useUnknownInCatchVariables01.ts

diff --git a/tests/cases/compiler/useUnknownInCatchVariables01.ts b/tests/cases/compiler/useUnknownInCatchVariables01.ts
new file mode 100644
index 00000000000..c9633c97e4f
--- /dev/null
+++ b/tests/cases/compiler/useUnknownInCatchVariables01.ts
@@ -0,0 +1,23 @@
+// @useUnknownInCatchVariables: true
+
+try {
+    // ...
+}
+catch (e) {
+    // error!
+    void e.toUpperCase();
+    void e++;
+    void e();
+
+    if (typeof e === "string") {
+        // works!
+        // We've narrowed 'e' down to the type 'string'.
+        console.log(e.toUpperCase());
+    }
+    if (e instanceof Error) {
+        e.stack?.toUpperCase();
+    }
+    if (typeof e === "number") {
+        e++;
+    }
+}
\ No newline at end of file