Reland of [sensors] Ambient light sensor implementation for ChromeOS and Linux.

device/generic_sensor/linux/sensor_reader_unittest.cc

Index: device/generic_sensor/linux/sensor_reader_unittest.cc
diff --git a/device/generic_sensor/linux/sensor_reader_unittest.cc b/device/generic_sensor/linux/sensor_reader_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..af4e28fbabf89fb2fb0d1365d0909b75e1eba441
--- /dev/null
+++ b/device/generic_sensor/linux/sensor_reader_unittest.cc
@@ -0,0 +1,260 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/strings/string_number_conversions.h"
+#include "device/generic_sensor/linux/platform_sensor_utils_linux.h"
+#include "device/generic_sensor/linux/sensor_data_linux.h"
+#include "device/generic_sensor/public/cpp/sensor_reading.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace device {
+
+namespace {
+
+const base::FilePath::CharType* kDevice0Dir = FILE_PATH_LITERAL("device0");
+
+const std::string kSensorFileNameTest1 = "sensor_data1";
+const std::string kSensorFileNameTest2 = "sensor_data2";
+const std::string kSensorFileNameTest3 = "sensor_data3";
+
+const std::string kTestSensorFileNamesTest[3][5] = {
+    {
+        kSensorFileNameTest1, "sensor1_input", "sensor1_raw_input", "sensor1",
+        "sensor1_data_raw",
+    },
+    {
+        "sensor2", kSensorFileNameTest2, "sensor2_raw_input", "sensor2_input",
+        "sensor2_data_raw",
+    },
+    {
+        "sensor3", "sensor3_input", "sensor3_raw_input", "sensor3_data_raw",
+        kSensorFileNameTest3,
+    },
+};
+
+void CreateFile(const base::FilePath& file) {
+  EXPECT_EQ(base::WriteFile(file, nullptr, 0), 0);
+}
+
+void DeleteFile(const base::FilePath& file) {
+  EXPECT_TRUE(base::DeleteFile(file, false));
+}
+
+void WriteReadingFieldToFile(const base::FilePath& path, double value) {
+  const std::string str = base::DoubleToString(value);
+  int bytes_written = base::WriteFile(path, str.data(), str.size());
+  EXPECT_EQ(static_cast<size_t>(bytes_written), str.size());
+}
+
+}  // namespace
+
+class SensorReaderTest : public ::testing::Test {
+ public:
+  void SetUp() override {
+    ASSERT_TRUE(base_temp_dir_.CreateUniqueTempDir());
+    base_dir_ = base_temp_dir_.GetPath();
+    sensors_dir_ = base_dir_.Append(kDevice0Dir);
+    ASSERT_TRUE(base::CreateDirectory(sensors_dir_));
+  }
+
+  // Deletes base dir recursively.
+  void TearDown() override { ASSERT_TRUE(base_temp_dir_.Delete()); }
+
+  // Initialize SensorDataLinux with values for a sensor reader.
+  void InitSensorDataForTest(size_t rows, SensorDataLinux* data) {
+    // Corresponds to maximum values in SensorReading.
+    // We must read only from up to three files. Thus - 3 sets of files
+    // should be fill in here.
+    const size_t max_rows = 3;
+    if (rows > 3)
+      rows = max_rows;
+
+    data->base_path_sensor_linux = base_dir_.value().c_str();
+    for (size_t i = 0; i < rows; ++i) {
+      std::vector<std::string> file_names(
+          kTestSensorFileNamesTest[i],
+          kTestSensorFileNamesTest[i] + arraysize(kTestSensorFileNamesTest[i]));
+      data->sensor_file_names.push_back(std::move(file_names));
+    }
+  }
+
+  // Check SensorReading values are properly read.
+  void CheckSensorDataFields(const SensorReading& data,
+                             double value1,
+                             double value2,
+                             double value3) {
+    EXPECT_EQ(value1, data.values[0]);
+    EXPECT_EQ(value2, data.values[1]);
+    EXPECT_EQ(value3, data.values[2]);
+  }
+
+ protected:
+  // Holds a path to a sensor dir that is located in |base_dir_|
+  base::FilePath sensors_dir_;
+  // Holds a path to a base dir.
+  base::FilePath base_dir_;
+  // Holds base dir where a sensor dir is located.
+  base::ScopedTempDir base_temp_dir_;
+};
+
+// Test a reader is not created if sensor read files
+// do not exist.
+TEST_F(SensorReaderTest, FileDoesNotExist) {
+  const char* kGiberishFiles[] = {"temp1", "temp2", "temp3", "temp4"};
+  const size_t rows = 3;
+  // Create some gibberish files that we are not interested in.
+  for (unsigned int i = 0; i < arraysize(kGiberishFiles); ++i) {
+    base::FilePath some_file = sensors_dir_.Append(kGiberishFiles[i]);
+    CreateFile(some_file);
+  }
+
+  SensorDataLinux sensor_data;
+  InitSensorDataForTest(rows, &sensor_data);
+
+  std::unique_ptr<SensorReader> reader = SensorReader::Create(sensor_data);
+  EXPECT_FALSE(reader);
+}
+
+// Simulate a sensor, which has only one file to be read from.
+TEST_F(SensorReaderTest, ReadValueFromOneFile) {
+  const size_t rows = 1;
+  const double value1 = 20;
+  const double zero_value = 0;
+  // Create a test sensor file, which must be found to be read from.
+  base::FilePath temp_sensor_file = sensors_dir_.Append(kSensorFileNameTest1);
+  CreateFile(temp_sensor_file);
+
+  // Initialize sensor data for a reader.
+  SensorDataLinux sensor_data;
+  InitSensorDataForTest(rows, &sensor_data);
+
+  std::unique_ptr<SensorReader> reader = SensorReader::Create(sensor_data);
+  EXPECT_TRUE(reader);
+
+  // Write a value to the file.
+  WriteReadingFieldToFile(temp_sensor_file, value1);
+
+  // Fill SensorReading's first field with read value. Other fields must
+  // be 0.
+  SensorReading reading;
+  EXPECT_TRUE(reader->ReadSensorReading(&reading));
+  CheckSensorDataFields(reading, value1, zero_value, zero_value);
+}
+
+// Simulate a sensor, which has two files to be read from.
+TEST_F(SensorReaderTest, ReadValuesFromTwoFiles) {
+  const size_t rows = 2;
+  const double value1 = 20;
+  const double value2 = 50;
+  const double zero_value = 0;
+  // Create a test sensor file, which must be found.
+  base::FilePath temp_sensor_file1 = sensors_dir_.Append(kSensorFileNameTest1);
+  CreateFile(temp_sensor_file1);
+
+  // Create another test sensor file, which must be found.
+  base::FilePath temp_sensor_file2 = sensors_dir_.Append(kSensorFileNameTest2);
+  CreateFile(temp_sensor_file2);
+
+  // Initialize sensor data for a reader.
+  SensorDataLinux sensor_data;
+  InitSensorDataForTest(rows, &sensor_data);
+
+  std::unique_ptr<SensorReader> reader = SensorReader::Create(sensor_data);
+  EXPECT_TRUE(reader);
+
+  // Write a value to the file.
+  WriteReadingFieldToFile(temp_sensor_file1, value1);
+  WriteReadingFieldToFile(temp_sensor_file2, value2);
+
+  // Fill SensorReading's two first fields with read value. Last field must
+  // be 0.
+  SensorReading reading;
+  EXPECT_TRUE(reader->ReadSensorReading(&reading));
+  CheckSensorDataFields(reading, value1, value2, zero_value);
+}
+
+// Simulate a sensor, which has the files to be read from.
+// After read is successful, remove one of the files and try
+// to read again. Reading must fail then.
+TEST_F(SensorReaderTest, ReadValuesFromThreeFilesAndFail) {
+  const size_t rows = 4;
+  const double value1 = 20;
+  const double value2 = 50;
+  const double value3 = 80;
+  const double zero_value = 0;
+  // Create a test sensor file, which must be found.
+  base::FilePath temp_sensor_file1 = sensors_dir_.Append(kSensorFileNameTest1);
+  CreateFile(temp_sensor_file1);
+
+  // Create another test sensor file, which must be found.
+  base::FilePath temp_sensor_file2 = sensors_dir_.Append(kSensorFileNameTest2);
+  CreateFile(temp_sensor_file2);
+
+  // Create third test sensor file, which must be found.
+  base::FilePath temp_sensor_file3 = sensors_dir_.Append(kSensorFileNameTest3);
+  CreateFile(temp_sensor_file3);
+
+  // Initialize sensor data for a reader.
+  SensorDataLinux sensor_data;
+  InitSensorDataForTest(rows, &sensor_data);
+
+  std::unique_ptr<SensorReader> reader = SensorReader::Create(sensor_data);
+  EXPECT_TRUE(reader);
+
+  // Write a value to the file.
+  WriteReadingFieldToFile(temp_sensor_file1, value1);
+  WriteReadingFieldToFile(temp_sensor_file2, value2);
+  WriteReadingFieldToFile(temp_sensor_file3, value3);
+
+  // Fill SensorReading's values with data from files.
+  SensorReading reading;
+  EXPECT_TRUE(reader->ReadSensorReading(&reading));
+  CheckSensorDataFields(reading, value1, value2, value3);
+
+  SensorReading reading2;
+  DeleteFile(temp_sensor_file2);
+  EXPECT_FALSE(reader->ReadSensorReading(&reading2));
+  CheckSensorDataFields(reading2, zero_value, zero_value, zero_value);
+}
+
+// Fill in SensorDataLinux with three arrays of files that must be found
+// before creating a sensor reader. If even one file is not found,
+// a sensor reader must not be created. As soon as all the files are found,
+// check the reader is created.
+TEST_F(SensorReaderTest, SensorReadFilesDoNotExist) {
+  const size_t rows = 3;
+  // Create a test sensor file, which must be found. Other
+  // files will not be created and the test must fail to create a reader.
+  base::FilePath temp_sensor_file1 = sensors_dir_.Append(kSensorFileNameTest1);
+  CreateFile(temp_sensor_file1);
+
+  // Initialize sensor data for a reader.
+  SensorDataLinux sensor_data;
+  InitSensorDataForTest(rows, &sensor_data);
+
+  std::unique_ptr<SensorReader> reader = SensorReader::Create(sensor_data);
+  EXPECT_FALSE(reader);
+
+  // Create one more file. The reader mustn't be created as long as it
+  // expects three files to be found.
+  base::FilePath temp_sensor_file2 = sensors_dir_.Append(kSensorFileNameTest2);
+  CreateFile(temp_sensor_file2);
+
+  reader.reset();
+  reader = SensorReader::Create(sensor_data);
+  EXPECT_FALSE(reader);
+
+  // Create last file.
+  base::FilePath temp_sensor_file3 = sensors_dir_.Append(kSensorFileNameTest3);
+  CreateFile(temp_sensor_file3);
+
+  reader.reset();
+  reader = SensorReader::Create(sensor_data);
+  EXPECT_TRUE(reader);
+}
+
+}  // namespace device