test: add scoped file helper tests and update test build targets

Makefile

@@ -5,27 +5,37 @@ CXXFLAGS := -std=c++17 \
             -Wextra \
             -Werror \
             -Icore/include \
-            -Ilogger/include
+            -Ilogger/include \
+            -Itests/helpers
 
 LDFLAGS := -lstdc++
 
 BUILD_DIR := build
 
-TEST_BIN := $(BUILD_DIR)/result_test
+
+RESULT_TEST_BIN := $(BUILD_DIR)/result_test
+SCOPED_FILE_TEST_BIN := $(BUILD_DIR)/scoped_file_test
 
 RESULT_TEST_SRC := tests/app/core/result_test.cpp
+SCOPED_FILE_TEST_SRC := tests/helpers/scoped_file_test.cpp
 
 
 .PHONY: all test clean
 
 all: test
 
-
-test: $(TEST_BIN)
-	./$(TEST_BIN)
+test: $(RESULT_TEST_BIN) \
+      $(SCOPED_FILE_TEST_BIN)
+	./$(RESULT_TEST_BIN)
+	./$(SCOPED_FILE_TEST_BIN)
 
 
-$(TEST_BIN): $(RESULT_TEST_SRC)
+$(RESULT_TEST_BIN): $(RESULT_TEST_SRC)
+	@mkdir -p $(BUILD_DIR)
+	$(CXX) $(CXXFLAGS) $< -o $@ $(LDFLAGS)
+
+
+$(SCOPED_FILE_TEST_BIN): $(SCOPED_FILE_TEST_SRC)
 	@mkdir -p $(BUILD_DIR)
 	$(CXX) $(CXXFLAGS) $< -o $@ $(LDFLAGS)
 

tests/helpers/scoped_file.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <filesystem>
+#include <stdexcept>
+#include <string>
+
+class ScopedFile {
+public:
+  explicit ScopedFile(std::string fileName) : fileName_(std::move(fileName)) {}
+
+  void throwIfExists() const {
+    if (std::filesystem::exists(fileName_)) {
+      throw std::runtime_error("Test file already exists: " + fileName_);
+    }
+  }
+
+  const std::string &getFileName() const { return fileName_; }
+
+  ~ScopedFile() noexcept(false) {
+    std::error_code ec;
+
+    std::filesystem::remove(fileName_, ec);
+  }
+
+private:
+  std::string fileName_;
+};

tests/helpers/scoped_file_test.cpp

@@ -0,0 +1,83 @@
+#include <cassert>
+#include <filesystem>
+#include <fstream>
+#include <stdexcept>
+#include <sys/stat.h>
+
+#include "scoped_file.hpp"
+
+namespace {
+
+void testFileRemovedAfterScope() {
+  const std::string fileName = "scoped_file_test.log";
+
+  {
+    ScopedFile file(fileName);
+
+    file.throwIfExists();
+
+    std::ofstream output(file.getFileName());
+
+    assert(output.is_open());
+
+    output << "test";
+
+    output.close();
+
+    assert(std::filesystem::exists(fileName));
+  } // call ~ScopedFile()
+
+  assert(!std::filesystem::exists(fileName));
+}
+
+void testThrowIfExists() {
+  const std::string fileName = "existing_file.log";
+
+  {
+    ScopedFile file(fileName);
+
+    if (std::filesystem::exists(fileName)) {
+      throw std::runtime_error("Test file already exists: " + fileName);
+    }
+
+    std::ofstream output(file.getFileName());
+
+    assert(output.is_open());
+
+    output.close();
+
+    bool thrown = false;
+
+    try {
+      file.throwIfExists();
+    } catch (const std::runtime_error &) {
+      thrown = true;
+    }
+
+    assert(thrown);
+  }
+
+  assert(!std::filesystem::exists(fileName));
+}
+
+void testGetFileName() {
+  ScopedFile file("test.log");
+
+  file.throwIfExists();
+
+  assert(file.getFileName() == "test.log");
+}
+
+void runTests() {
+  testFileRemovedAfterScope();
+  testThrowIfExists();
+  testGetFileName();
+}
+
+} // namespace
+
+int main() {
+  runTests();
+
+  return 0;
+}