test/pagespeed/kernel/image/jpeg_utils_test.cc

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
 * 
 *   http://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.
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#include "pagespeed/kernel/image/jpeg_utils.h"

#include "pagespeed/kernel/base/null_mutex.h"
#include "pagespeed/kernel/base/string.h"
#include "test/pagespeed/kernel/base/gtest.h"
#include "test/pagespeed/kernel/base/mock_message_handler.h"
#include "test/pagespeed/kernel/image/test_utils.h"

// DO NOT INCLUDE LIBJPEG HEADERS HERE. Doing so causes build errors
// on Windows. If you need to call out to libjpeg, please add helper
// methods in jpeg_optimizer_test_helper.h.

namespace {

using net_instaweb::MockMessageHandler;
using net_instaweb::NullMutex;
using pagespeed::image_compression::JpegUtils;

// The JPEG_TEST_DIR_PATH macro is set by the gyp target that builds this file.
const char* kColorJpegFile = "sjpeg2";
const char* kGreyScaleJpegFile = "testgray";
const char* kEmptyJpegFile = "emptyfile";
const char* kQuality100JpegFile = "quality100";

// Given one of the above file names, read the contents of the file into the
// given destination string.

using pagespeed::image_compression::kJpegTestDir;
using pagespeed::image_compression::ReadTestFile;

TEST(JpegUtilsTest, GetImageQualityFromImage) {
  MockMessageHandler message_handler(new NullMutex);
  GoogleString src_data;
  ReadTestFile(kJpegTestDir, kGreyScaleJpegFile, "jpg", &src_data);
  EXPECT_EQ(85, JpegUtils::GetImageQualityFromImage(
                    src_data.data(), src_data.size(), &message_handler));

  src_data.clear();
  ReadTestFile(kJpegTestDir, kColorJpegFile, "jpg", &src_data);
  EXPECT_EQ(75, JpegUtils::GetImageQualityFromImage(
                    src_data.data(), src_data.size(), &message_handler));

  src_data.clear();
  ReadTestFile(kJpegTestDir, kEmptyJpegFile, "jpg", &src_data);
  EXPECT_EQ(-1, JpegUtils::GetImageQualityFromImage(
                    src_data.data(), src_data.size(), &message_handler));

  src_data.clear();
  ReadTestFile(kJpegTestDir, kQuality100JpegFile, "jpg", &src_data);
  EXPECT_EQ(100, JpegUtils::GetImageQualityFromImage(
                     src_data.data(), src_data.size(), &message_handler));
}

}  // namespace