1 files changed, 40 insertions, 0 deletions
diff --git a/src/strings/clone_test.go b/src/strings/clone_test.go
new file mode 100644
index 0000000000..5396771047
--- /dev/null
+++ b/src/strings/clone_test.go
@@ -0,0 +1,40 @@
+// Copyright 2021 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.ß
+
+package strings_test
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+	"unsafe"
+)
+
+func TestClone(t *testing.T) {
+	var cloneTests = []string{
+		"",
+		"short",
+		strings.Repeat("a", 42),
+	}
+	for _, input := range cloneTests {
+		clone := strings.Clone(input)
+		if clone != input {
+			t.Errorf("Clone(%q) = %q; want %q", input, clone, input)
+		}
+
+		inputHeader := (*reflect.StringHeader)(unsafe.Pointer(&input))
+		cloneHeader := (*reflect.StringHeader)(unsafe.Pointer(&clone))
+		if inputHeader.Data == cloneHeader.Data {
+			t.Errorf("Clone(%q) return value should not reference inputs backing memory.", input)
+		}
+	}
+}
+
+func BenchmarkClone(b *testing.B) {
+	var str = strings.Repeat("a", 42)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		stringSink = strings.Clone(str)
+	}
+}