util: add internal function _deprecationWarning()

1 files changed, 16 insertions, 0 deletions

diff --git a/lib/util.js b/lib/util.js
index b00da2de9d..cd4cc0e964 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -518,3 +518,19 @@ exports.inherits = function(ctor, superCtor) {
     }
   });
 };
+
+var deprecationWarnings;
+
+exports._deprecationWarning = function(moduleId, message) {
+  if (!deprecationWarnings)
+    deprecationWarnings = {};
+  else if (message in deprecationWarnings)
+    return;
+
+  deprecationWarnings[message] = true;
+
+  if ((new RegExp('\\b' + moduleId + '\\b')).test(process.env.NODE_DEBUG))
+    console.trace(message);
+  else
+    console.error(message);
+};