core: add `NativeModule.prototype.deprecate`

Formalize and cleanup handling of deprecated core methods.

lib/http.js

@@ -1606,9 +1606,7 @@ exports._connectionListener = connectionListener;
 // Legacy Interface
 
 function Client(port, host) {
-  // TODO http.Client can be removed in v0.9. Until then leave this message.
-  util._deprecationWarning('http', 'http.Client is a legacy interface' +
-                ' and will be removed in the near future. Do not use it.');
+  if (!(this instanceof Client)) return new Client(port, host);
   host = host || 'localhost';
   port = port || 80;
   this.host = host;
@@ -1646,6 +1644,11 @@ Client.prototype.request = function(method, path, headers) {
 };
 
 exports.Client = Client;
+
+// TODO http.Client can be removed in v0.9. Until then leave this message.
+module.deprecate('Client', 'It will be removed in the near future. Do not use it.');
+
 exports.createClient = function(port, host) {
   return new Client(port, host);
 };
+module.deprecate('createClient', 'Use `http.request` instead.');

lib/os.js

@@ -38,7 +38,6 @@ exports.platform = function() {
 };
 
 exports.getNetworkInterfaces = function() {
-  require('util')._deprecationWarning('os',
-    'os.getNetworkInterfaces() is deprecated - use os.networkInterfaces()');
   return exports.networkInterfaces();
 };
+module.deprecate('getNetworkInterfaces', 'It is now called `os.networkInterfaces`.');

lib/path.js

@@ -403,15 +403,15 @@ exports.extname = function(path) {
 
 
 exports.exists = function(path, callback) {
-  _deprecationWarning('path', '`path.exists` is now called `fs.exists`');
   require('fs').exists(path, callback);
 };
+module.deprecate('exists', 'It is now called `fs.exists`.');
 
 
 exports.existsSync = function(path) {
-  _deprecationWarning('path', '`path.exists` is now called `fs.exists`');
   return require('fs').existsSync(path);
 };
+module.deprecate('existsSync', 'It is now called `fs.existsSync`.');
 
 
 exports._makeLong = isWindows ?

lib/util.js

@@ -407,18 +407,12 @@ function objectToString(o) {
 }
 
 
-var pWarning;
-
 exports.p = function() {
-  if (!pWarning) {
-    pWarning = 'util.p will be removed in future versions of Node. ' +
-               'Use util.puts(util.inspect()) instead.\n';
-    exports.error(pWarning);
-  }
   for (var i = 0, len = arguments.length; i < len; ++i) {
     error(exports.inspect(arguments[i]));
   }
 };
+module.deprecate('p', 'Use `util.puts(util.inspect())` instead.');
 
 
 function pad(n) {
@@ -444,15 +438,10 @@ exports.log = function(msg) {
 };
 
 
-var execWarning;
 exports.exec = function() {
-  if (!execWarning) {
-    execWarning = 'util.exec has moved to the "child_process" module.' +
-                  ' Please update your source code.';
-    error(execWarning);
-  }
   return require('child_process').exec.apply(this, arguments);
 };
+module.deprecate('exec', 'It is now called `child_process.exec`.');
 
 
 exports.pump = function(readStream, writeStream, callback) {
@@ -517,19 +506,3 @@ 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);
-};

src/node.js

@@ -569,5 +569,25 @@
     NativeModule._cache[this.id] = this;
   };
 
+  NativeModule.prototype.deprecate = function(method, message) {
+    var original = this.exports[method];
+    var self = this;
+
+    Object.defineProperty(this.exports, method, {
+      enumerable: false,
+      value: function() {
+        message = self.id + '.' + method + ' is deprecated. ' + (message || '');
+
+        if ((new RegExp('\\b' + self.id + '\\b')).test(process.env.NODE_DEBUG))
+          console.trace(message);
+        else
+          console.error(message);
+
+        self.exports[method] = original;
+        return original.apply(this, arguments);
+      }
+    });
+  };
+
   startup();
 });