src: improve node::Dotenv declarations

There is no need to explicitly allow copy constructor and copy
assignment, and some of these functions should be marked as const.

PR-URL: nodejs#52973
Reviewed-By: Yagiz Nizipli <yagiz.nizipli@sentry.io>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

src/node_dotenv.cc

@@ -42,10 +42,6 @@ std::vector<std::string> Dotenv::GetPathFromArgs(
 }
 
 void Dotenv::SetEnvironment(node::Environment* env) {
-  if (store_.empty()) {
-    return;
-  }
-
   auto isolate = env->isolate();
 
   for (const auto& entry : store_) {
@@ -67,7 +63,7 @@ void Dotenv::SetEnvironment(node::Environment* env) {
   }
 }
 
-Local<Object> Dotenv::ToObject(Environment* env) {
+Local<Object> Dotenv::ToObject(Environment* env) const {
   Local<Object> result = Object::New(env->isolate());
 
   for (const auto& entry : store_) {
@@ -263,7 +259,7 @@ Dotenv::ParseResult Dotenv::ParsePath(const std::string_view path) {
   return ParseResult::Valid;
 }
 
-void Dotenv::AssignNodeOptionsIfAvailable(std::string* node_options) {
+void Dotenv::AssignNodeOptionsIfAvailable(std::string* node_options) const {
   auto match = store_.find("NODE_OPTIONS");
 
   if (match != store_.end()) {

src/node_dotenv.h

@@ -15,17 +15,17 @@ class Dotenv {
   enum ParseResult { Valid, FileError, InvalidContent };
 
   Dotenv() = default;
-  Dotenv(const Dotenv& d) = default;
+  Dotenv(const Dotenv& d) = delete;
   Dotenv(Dotenv&& d) noexcept = default;
   Dotenv& operator=(Dotenv&& d) noexcept = default;
-  Dotenv& operator=(const Dotenv& d) = default;
+  Dotenv& operator=(const Dotenv& d) = delete;
   ~Dotenv() = default;
 
   void ParseContent(const std::string_view content);
   ParseResult ParsePath(const std::string_view path);
-  void AssignNodeOptionsIfAvailable(std::string* node_options);
+  void AssignNodeOptionsIfAvailable(std::string* node_options) const;
   void SetEnvironment(Environment* env);
-  v8::Local<v8::Object> ToObject(Environment* env);
+  v8::Local<v8::Object> ToObject(Environment* env) const;
 
   static std::vector<std::string> GetPathFromArgs(
       const std::vector<std::string>& args);