Add unit tests for core C++ functions

CMakeLists.txt

@@ -12,6 +12,10 @@ set(CURL_LIBRARY "C:/vcpkg/installed/x64-windows/lib/libcurl.a")
 set(CMAKE_BUILD_TYPE Debug)
 add_executable(main main.cpp)
 
+add_executable(unit_tests tests/test_main.cpp)
+
 target_link_libraries(main PRIVATE nlohmann_json::nlohmann_json)
 
-target_link_libraries(main PRIVATE CURL::libcurl)
+target_link_libraries(main PRIVATE CURL::libcurl)
+
+target_link_libraries(unit_tests PRIVATE nlohmann_json::nlohmann_json)

main.cpp

@@ -1,10 +1,14 @@
+#ifndef UNIT_TESTING
 #include <curl/curl.h>
+#endif
 #include <string.h>
 
 #include <unordered_set>
 #include <iostream>
 #include <fstream>
 #include <map>
+#include <algorithm>
+#include <filesystem>
 #include <nlohmann/json.hpp>
 
 using json = nlohmann::json;
@@ -29,8 +33,9 @@ std::string FormatHTMLToString(const std::string &response);
 TestCaseResponse GetTestCases(const std::string &content);
 
 std::pair<std::string, std::string> GetParamName(const std::string &param);
-void CreateJSON(json *response, const TestCaseResponse &testCases);
+void CreateJSON(json *response, const TestCaseResponse &testCases, const std::string &outputDir = "../../../Questions");
 
+#ifndef UNIT_TESTING
 int main()
 {
   std::string questionName = "";
@@ -104,6 +109,7 @@ int main()
   curl_easy_cleanup(curl);
   return 0;
 }
+#endif
 
 // returns number of bytes in the chunk
 //  data is set to a ptr that points to block of data recieved in this chunk
@@ -369,23 +375,35 @@ TestCaseResponse GetTestCases(const std::string &content)
   return tests;
 }
 
-void CreateJSON(json *response, const TestCaseResponse &tests)
+void CreateJSON(json *response, const TestCaseResponse &tests, const std::string &outputDir)
 {
+  namespace fs = std::filesystem;
   // filter out invalid characters from title
   std::string title = (*response)["title"];
   const std::string invalid_chars = "\\/:*?\"<>|";
   for (char c : invalid_chars)
   {
     std::replace(title.begin(), title.end(), c, '_');
   }
-  std::string jsonName = "../../../Questions/" + title + ".txt";
+  fs::path basePath(outputDir);
+  std::error_code ec;
+  if (!fs::exists(basePath))
+  {
+    fs::create_directories(basePath, ec);
+    if (ec)
+    {
+      std::cerr << "Error creating output directory: " << ec.message() << std::endl;
+      return;
+    }
+  }
+  fs::path outputPath = basePath / (title + ".txt");
 
   std::ofstream outputJSON;
-  outputJSON.open(jsonName);
+  outputJSON.open(outputPath);
   // should have to create the file so always should open
   if (!outputJSON.is_open())
   {
-    std::cerr << "Error creating output file for JSON response" << std::endl;
+    std::cerr << "Error creating output file for JSON response: " << outputPath << std::endl;
     return;
   }
 

tests/test_main.cpp

@@ -0,0 +1,82 @@
+#define UNIT_TESTING
+
+#include <cassert>
+#include <filesystem>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <iostream>
+
+#include "../main.cpp"
+
+void TestFormatHTMLToString()
+{
+  std::string html = "<div>Value:&nbsp;&lt;tag&gt;&#39;s</div>\n\nNext\t\tLine";
+  std::string expected = "Value:<tag>\nNextLine";
+  auto formatted = FormatHTMLToString(html);
+  assert(formatted == expected);
+}
+
+void TestGetParamName()
+{
+  auto param = GetParamName("nums = [1, 2, 3]");
+  assert(param.first == "nums");
+  assert(param.second == "[1,2,3]");
+}
+
+void TestGetTestCases()
+{
+  std::string content =
+      "Example 1:\n"
+      "Input: nums = [1, 2, 3], k = 3\n"
+      "Output: 2\n"
+      "Example 2:\n"
+      "Input: nums = [1, 2], k = 1\n"
+      "Output: 1\n";
+
+  TestCaseResponse tests = GetTestCases(content);
+  assert(tests.testCases.size() == 2);
+  assert(tests.testCases[0] == "2");
+  assert(tests.testCases[1] == "1");
+  assert(tests.testCaseParams.size() == 4);
+  assert(tests.testCaseParams[0] == std::make_pair(std::string("nums"), std::string("[1,2,3]")));
+  assert(tests.testCaseParams[1] == std::make_pair(std::string("k"), std::string("3")));
+}
+
+void TestCreateJSON()
+{
+  json response = {{"title", "Sample/Title"}, {"content", "desc"}, {"difficulty", "Easy"}};
+  TestCaseResponse tests;
+  tests.testCases = {"42"};
+  tests.testCaseParams = {{"nums", "[1,2,3]"}, {"k", "3"}};
+
+  std::filesystem::path tempRoot = std::filesystem::temp_directory_path() / "leetcode_tests";
+  std::filesystem::remove_all(tempRoot);
+
+  std::filesystem::path outputDir = tempRoot / "Questions";
+  CreateJSON(&response, tests, outputDir.string());
+
+  std::filesystem::path outputFile = outputDir / "Sample_Title.txt";
+  assert(std::filesystem::exists(outputFile));
+
+  std::ifstream input(outputFile);
+  std::stringstream buffer;
+  buffer << input.rdbuf();
+  std::string content = buffer.str();
+  assert(content.find("\"expectedResult\": \"42\"") != std::string::npos);
+  assert(content.find("\"nums\": \"[1,2,3]\"") != std::string::npos);
+  assert(content.find("\"k\": \"3\"") != std::string::npos);
+
+  std::filesystem::remove_all(tempRoot);
+}
+
+int main()
+{
+  TestFormatHTMLToString();
+  TestGetParamName();
+  TestGetTestCases();
+  TestCreateJSON();
+
+  std::cout << "All tests passed!" << std::endl;
+  return 0;
+}