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 {

using namespace logger;

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

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

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

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

  assert(logger.getLogLevel() == LogLevel::info());
  assert(debugLogger.getLogLevel() == LogLevel::debug());

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

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

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

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

  assert(newLogger.getLogLevel() == LogLevel::info());
}

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

  file.throwIfExists();

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

  auto result = logger.writeMessage(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(file.getFileName(), LogLevel::info());

  auto result = logger.writeMessage(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(file.getFileName(), LogLevel::info());

  auto first = logger.writeMessage(LogLevel::info(), "first message");

  auto second = logger.writeMessage(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;
}