cpp17-threaded-app-non-threadsafe-logger/tests/logger/logger_test.cpp

#include <cassert>
#include <filesystem>
#include <fstream>
#include <string>

#include "logger.hpp"
#include "scoped_file.hpp"

namespace {

void testLoggerCreation() {
  logger::Logger logger("test.log", logger::LogLevel::Info);

  assert(logger.getFileName() == "test.log");
  assert(logger.getLogLevel() == logger::LogLevel::Info);
}

void testWithLogLevel() {
  logger::Logger logger("test.log", logger::LogLevel::Info);

  auto debugLogger = logger.withLogLevel(logger::LogLevel::Debug);

  assert(logger.getLogLevel() == logger::LogLevel::Info);
  assert(debugLogger.getLogLevel() == logger::LogLevel::Debug);

  assert(debugLogger.getFileName() == "test.log");
}

void testWithFileName() {
  logger::Logger logger("old.log", logger::LogLevel::Info);

  auto newLogger = logger.withFileName("new.log");

  assert(logger.getFileName() == "old.log");
  assert(newLogger.getFileName() == "new.log");

  assert(newLogger.getLogLevel() == logger::LogLevel::Info);
}

void testWriteLogSuccess() {
  ScopedFile file("logger_test.log");

  file.throwIfExists();

  logger::Logger logger(file.getFileName(), logger::LogLevel::Info);

  auto result = logger.writeLog(logger::LogLevel::Info, "Application started");

  assert(result.isSuccess());
  assert(result.getValue());

  std::ifstream input(file.getFileName());

  assert(input.is_open());

  std::string content;
  std::getline(input, content);

  assert(content.find("Application started") != std::string::npos);
}

void testWriteLogFailure() {
  ScopedFile file("logger_test_directory");

  file.throwIfExists();

  std::filesystem::create_directory(file.getFileName());

  logger::Logger logger(file.getFileName(), logger::LogLevel::Info);

  auto result = logger.writeLog(logger::LogLevel::Info, "message");

  assert(result.isFailure());
  assert(!result.getError().empty());

  std::filesystem::remove(file.getFileName());
}

void testMultipleWrites() {
  ScopedFile file("multiple.log");

  file.throwIfExists();

  logger::Logger logger(file.getFileName(), logger::LogLevel::Info);

  auto first = logger.writeLog(logger::LogLevel::Info, "first message");

  auto second = logger.writeLog(logger::LogLevel::Error, "second message");

  assert(first.isSuccess());
  assert(second.isSuccess());

  std::ifstream input(file.getFileName());

  assert(input.is_open());

  std::string firstLine;
  std::string secondLine;

  std::getline(input, firstLine);
  std::getline(input, secondLine);

  assert(firstLine.find("first message") != std::string::npos);

  assert(secondLine.find("second message") != std::string::npos);
}

void runTests() {
  testLoggerCreation();
  testWithLogLevel();
  testWithFileName();
  testWriteLogSuccess();
  testWriteLogFailure();
  testMultipleWrites();
}

} // namespace

int main() {
  runTests();

  return 0;
}