module: add warnings for experimental flags

PR-URL: https://github.com/nodejs/node/pull/30617
Fixes: https://github.com/nodejs/node/issues/30600
Reviewed-By: Guy Bedford <guybedford@gmail.com>

3 files changed, 21 insertions, 0 deletions

diff --git a/src/module_wrap.cc b/src/module_wrap.cc
index 3c3d568329..2fa8ba498e 100644
--- a/src/module_wrap.cc
+++ b/src/module_wrap.cc
@@ -7,6 +7,7 @@
 #include "util-inl.h"
 #include "node_contextify.h"
 #include "node_watchdog.h"
+#include "node_process.h"
 
 #include <sys/stat.h>  // S_IFDIR
 
@@ -962,6 +963,7 @@ Maybe<URL> ResolveExportsTarget(Environment* env,
       Maybe<URL> resolved = ResolveExportsTarget(env, pjson_url,
             conditionalTarget, subpath, pkg_subpath, base, false);
       if (!resolved.IsNothing()) {
+        ProcessEmitExperimentalWarning(env, "Conditional exports");
         return resolved;
       }
     }
@@ -1267,6 +1269,7 @@ Maybe<URL> PackageResolve(Environment* env,
 
   Maybe<URL> self_url = ResolveSelf(env, specifier, base);
   if (self_url.IsJust()) {
+    ProcessEmitExperimentalWarning(env, "Package name self resolution");
     return self_url;
   }
 
diff --git a/src/node_process.h b/src/node_process.h
index 5db7b004d6..ad86b449f9 100644
--- a/src/node_process.h
+++ b/src/node_process.h
@@ -27,6 +27,8 @@ v8::Maybe<bool> ProcessEmitWarningGeneric(Environment* env,
                                           const char* code = nullptr);
 
 v8::Maybe<bool> ProcessEmitWarning(Environment* env, const char* fmt, ...);
+v8::Maybe<bool> ProcessEmitExperimentalWarning(Environment* env,
+                                              const char* warning);
 v8::Maybe<bool> ProcessEmitDeprecationWarning(Environment* env,
                                               const char* warning,
                                               const char* deprecation_code);
diff --git a/src/node_process_events.cc b/src/node_process_events.cc
index 0609622662..d192ef19b7 100644
--- a/src/node_process_events.cc
+++ b/src/node_process_events.cc
@@ -1,4 +1,5 @@
 #include <cstdarg>
+#include <set>
 
 #include "env-inl.h"
 #include "node_process.h"
@@ -95,6 +96,21 @@ Maybe<bool> ProcessEmitWarning(Environment* env, const char* fmt, ...) {
   return ProcessEmitWarningGeneric(env, warning);
 }
 
+
+std::set<std::string> experimental_warnings;
+
+Maybe<bool> ProcessEmitExperimentalWarning(Environment* env,
+                                          const char* warning) {
+  if (experimental_warnings.find(warning) != experimental_warnings.end())
+    return Nothing<bool>();
+
+  experimental_warnings.insert(warning);
+  std::string message(warning);
+  message.append(
+      " is an experimental feature. This feature could change at any time");
+  return ProcessEmitWarningGeneric(env, message.c_str(), "ExperimentalWarning");
+}
+
 Maybe<bool> ProcessEmitDeprecationWarning(Environment* env,
                                           const char* warning,
                                           const char* deprecation_code) {