1 files changed, 40 insertions, 0 deletions
diff --git a/absl/strings/has_absl_stringify_test.cc b/absl/strings/has_absl_stringify_test.cc
new file mode 100644
index 00000000..59e7e1d3
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+++ b/absl/strings/has_absl_stringify_test.cc
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+// Copyright 2023 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/has_absl_stringify.h"
+
+#include <string>
+
+#include "gtest/gtest.h"
+#include "absl/types/optional.h"
+
+namespace {
+
+struct TypeWithoutAbslStringify {};
+
+struct TypeWithAbslStringify {
+  template <typename Sink>
+  friend void AbslStringify(Sink&, const TypeWithAbslStringify&) {}
+};
+
+TEST(HasAbslStringifyTest, Works) {
+  EXPECT_FALSE(absl::HasAbslStringify<int>::value);
+  EXPECT_FALSE(absl::HasAbslStringify<std::string>::value);
+  EXPECT_FALSE(absl::HasAbslStringify<TypeWithoutAbslStringify>::value);
+  EXPECT_TRUE(absl::HasAbslStringify<TypeWithAbslStringify>::value);
+  EXPECT_FALSE(
+      absl::HasAbslStringify<absl::optional<TypeWithAbslStringify>>::value);
+}
+
+}  // namespace