text: // Copyright 2017 Google Inc.
  //
  // 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
  //
  //    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.
  
  #include "internal/stack_line_reader.h"
  #include "filesystem_for_testing.h"
  
  #include "gtest/gtest.h"
  
  namespace cpu_features {
  
  bool operator==(const StringView& a, const StringView& b) {
    return IsEquals(a, b);
  }
  
  namespace {
  
  std::string ToString(StringView view) { return {view.ptr, view.size}; }
  
  TEST(StackLineReaderTest, Empty) {
    auto& fs = GetEmptyFilesystem();
    auto* file = fs.CreateFile("/proc/cpuinfo", "");
    StackLineReader reader;
    StackLineReader_Initialize(&reader, file->GetFileDescriptor());
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_TRUE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str(""));
    }
  }
  
  TEST(StackLineReaderTest, ManySmallLines) {
    auto& fs = GetEmptyFilesystem();
    auto* file = fs.CreateFile("/proc/cpuinfo", "a\nb\nc");
  
    StackLineReader reader;
    StackLineReader_Initialize(&reader, file->GetFileDescriptor());
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str("a"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str("b"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_TRUE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str("c"));
    }
  }
  
  TEST(StackLineReaderTest, TruncatedLine) {
    auto& fs = GetEmptyFilesystem();
    auto* file = fs.CreateFile("/proc/cpuinfo", R"(First
  Second
  More than 16 characters, this will be truncated.
  last)");
  
    StackLineReader reader;
    StackLineReader_Initialize(&reader, file->GetFileDescriptor());
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str("First"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str("Second"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_FALSE(result.full_line);
      EXPECT_EQ(result.line, str("More than 16 cha"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_TRUE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str("last"));
    }
  }
  
  TEST(StackLineReaderTest, TruncatedLines) {
    auto& fs = GetEmptyFilesystem();
    auto* file = fs.CreateFile("/proc/cpuinfo", R"(More than 16 characters
  Another line that is too long)");
  
    StackLineReader reader;
    StackLineReader_Initialize(&reader, file->GetFileDescriptor());
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_FALSE(result.full_line);
      EXPECT_EQ(result.line, str("More than 16 cha"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_FALSE(result.eof);
      EXPECT_FALSE(result.full_line);
      EXPECT_EQ(result.line, str("Another line tha"));
    }
    {
      const auto result = StackLineReader_NextLine(&reader);
      EXPECT_TRUE(result.eof);
      EXPECT_TRUE(result.full_line);
      EXPECT_EQ(result.line, str(""));
    }
  }
  
  }  // namespace
  }  // namespace cpu_features
  