test/protobuf_matchers.h

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_TEST_PROTOBUF_MATCHERS_H_
#define BASE_TEST_PROTOBUF_MATCHERS_H_

#include <string>
#include <tuple>

#include "testing/gmock/include/gmock/gmock-matchers.h"

namespace base::test {

// Parses a binary proto and returns a raw TextProto, where all fields are
// unnamed. The input must be a valid serialized protobuf message.
std::string BinaryProtoToRawTextProto(const std::string& binary_message);

// Matcher that verifies two protobufs contain the same data.
MATCHER_P(EqualsProto,
          message,
          "Match a proto Message equal to the matcher's argument.") {
  std::string expected_serialized;
  if (!message.SerializeToString(&expected_serialized)) {
    *result_listener << "Expected proto fails to serialize";
    return false;
  }
  std::string actual_serialized;
  if (!arg.SerializeToString(&actual_serialized)) {
    *result_listener << "Actual proto fails to serialize";
    return false;
  }
  if (expected_serialized != actual_serialized) {
    *result_listener << "Provided proto did not match the expected proto"
                     << "\n Expected Raw TextProto:\n"
                     << BinaryProtoToRawTextProto(expected_serialized)
                     << "\n Provided Raw TextProto:\n"
                     << BinaryProtoToRawTextProto(actual_serialized);
    return false;
  }
  return true;
}

// EqualsProto() implementation for 2-tuple matchers.
MATCHER(EqualsProto,
        "Matches if the tuple's proto Message arguments are equal.") {
  return ::testing::Matcher<decltype(std::get<0>(arg))>(
             EqualsProto(std::get<1>(arg)))
      .MatchAndExplain(std::get<0>(arg), result_listener);
}

}  // namespace base::test

#endif  // BASE_TEST_PROTOBUF_MATCHERS_H_