1 files changed, 35 insertions, 0 deletions
diff --git a/test/switch7.go b/test/switch7.go
new file mode 100644
index 0000000..7506066
--- /dev/null
+++ b/test/switch7.go
@@ -0,0 +1,35 @@
+// errorcheck
+
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Verify that type switch statements with duplicate cases are detected
+// by the compiler.
+// Does not compile.
+
+package main
+
+import "fmt"
+
+func f4(e interface{}) {
+	switch e.(type) {
+	case int:
+	case int: // ERROR "duplicate case int in type switch"
+	case int64:
+	case error:
+	case error: // ERROR "duplicate case error in type switch"
+	case fmt.Stringer:
+	case fmt.Stringer: // ERROR "duplicate case fmt.Stringer in type switch"
+	case struct {
+		i int "tag1"
+	}:
+	case struct {
+		i int "tag2"
+	}:
+	case struct { // ERROR "duplicate case struct { i int .tag1. } in type switch"
+		i int "tag1"
+	}:
+	}
+}
+