internal: add emitExperimentalWarning function

Adds a new emitExperimentalWarning function to internal/util to warn users that they are using an experimental feature and that feature can change at any time. PR-URL: #16497 Refs: #9036 Reviewed-By: Michael Dawson <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: Michaël Zasso <[email protected]>
nodejs · Dec 12, 2017 · 8fd316f · 8fd316f
1 parent 821951e
commit 8fd316f
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/lib/internal/util.js b/lib/internal/util.js
@@ -10,6 +10,8 @@ const kArrowMessagePrivateSymbolIndex = binding['arrow_message_private_symbol'];
 const kDecoratedPrivateSymbolIndex = binding['decorated_private_symbol'];
 const noCrypto = !process.versions.openssl;
 
+const experimentalWarnings = new Set();
+
 function isError(e) {
   return objectToString(e) === '[object Error]' || e instanceof Error;
 }
@@ -115,6 +117,14 @@ function normalizeEncoding(enc) {
   }
 }
 
+function emitExperimentalWarning(feature) {
+  if (experimentalWarnings.has(feature)) return;
+  const msg = `${feature} is an experimental feature. This feature could ` +
+       'change at any time';
+  experimentalWarnings.add(feature);
+  process.emitWarning(msg, 'ExperimentalWarning');
+}
+
 function filterDuplicateStrings(items, low) {
   const map = new Map();
   for (var i = 0; i < items.length; i++) {
@@ -285,6 +295,7 @@ module.exports = {
   createClassWrapper,
   decorateErrorStack,
   deprecate,
+  emitExperimentalWarning,
   filterDuplicateStrings,
   getConstructorOf,
   isError,