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>

2 files changed, 13 insertions, 6 deletions

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index 0b98fb9d4f..11c04e3e0c 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -46,7 +46,7 @@ const {
   rekeySourceMap
 } = require('internal/source_map/source_map_cache');
 const { pathToFileURL, fileURLToPath, URL } = require('internal/url');
-const { deprecate } = require('internal/util');
+const { deprecate, emitExperimentalWarning } = require('internal/util');
 const vm = require('vm');
 const assert = require('internal/assert');
 const fs = require('fs');
@@ -587,8 +587,10 @@ function resolveExportsTarget(pkgPath, target, subpath, basePath, mappingKey) {
     if (experimentalConditionalExports &&
         ObjectPrototypeHasOwnProperty(target, 'require')) {
       try {
-        return resolveExportsTarget(pkgPath, target.require, subpath,
-                                    basePath, mappingKey);
+        const result = resolveExportsTarget(pkgPath, target.require, subpath,
+                                            basePath, mappingKey);
+        emitExperimentalWarning('Conditional exports');
+        return result;
       } catch (e) {
         if (e.code !== 'MODULE_NOT_FOUND') throw e;
       }
@@ -596,8 +598,10 @@ function resolveExportsTarget(pkgPath, target, subpath, basePath, mappingKey) {
     if (experimentalConditionalExports &&
         ObjectPrototypeHasOwnProperty(target, 'node')) {
       try {
-        return resolveExportsTarget(pkgPath, target.node, subpath,
-                                    basePath, mappingKey);
+        const result = resolveExportsTarget(pkgPath, target.node, subpath,
+                                            basePath, mappingKey);
+        emitExperimentalWarning('Conditional exports');
+        return result;
       } catch (e) {
         if (e.code !== 'MODULE_NOT_FOUND') throw e;
       }
@@ -700,6 +704,7 @@ Module._findPath = function(request, paths, isMain) {
 
   const selfFilename = trySelf(paths, exts, isMain, trailingSlash, request);
   if (selfFilename) {
+    emitExperimentalWarning('Package name self resolution');
     Module._pathCache[cacheKey] = selfFilename;
     return selfFilename;
   }
diff --git a/lib/internal/modules/esm/translators.js b/lib/internal/modules/esm/translators.js
index dafc1b02f0..99e4c01405 100644
--- a/lib/internal/modules/esm/translators.js
+++ b/lib/internal/modules/esm/translators.js
@@ -22,7 +22,7 @@ const createDynamicModule = require(
 const fs = require('fs');
 const { fileURLToPath, URL } = require('url');
 const { debuglog } = require('internal/util/debuglog');
-const { promisify } = require('internal/util');
+const { promisify, emitExperimentalWarning } = require('internal/util');
 const {
   ERR_INVALID_URL,
   ERR_INVALID_URL_SCHEME,
@@ -133,6 +133,7 @@ translators.set('builtin', async function builtinStrategy(url) {
 
 // Strategy for loading a JSON file
 translators.set('json', async function jsonStrategy(url) {
+  emitExperimentalWarning('Importing JSON modules');
   debug(`Translating JSONModule ${url}`);
   debug(`Loading JSONModule ${url}`);
   const pathname = url.startsWith('file:') ? fileURLToPath(url) : null;
@@ -187,6 +188,7 @@ translators.set('json', async function jsonStrategy(url) {
 
 // Strategy for loading a wasm module
 translators.set('wasm', async function(url) {
+  emitExperimentalWarning('Importing Web Assembly modules');
   const buffer = await getSource(url);
   debug(`Translating WASMModule ${url}`);
   let compiled;