readline: fix close event of readline.Interface()

Not removing 'end' listeners for input and output on the 'close' event
resulted in an EventEmitter related memory leak.

This issue also might be reproduced at:
https://github.com/npm/npm/issues/5203

Signed-off-by: Trevor Norris <trev.norris@gmail.com>

diff --git a/lib/readline.js b/lib/readline.js
index 1fa217c..19ef759 100644 (file)
--- a/lib/readline.js
+++ b/lib/readline.js
@@ -97,6 +97,13 @@ function Interface(input, output, completer, terminal) {
     self.close();
   }
 
+  function ontermend() {
+    if (util.isString(self.line) && self.line.length > 0) {
+      self.emit('line', self.line);
+    }
+    self.close();
+  }
+
   function onkeypress(s, key) {
     self._ttyWrite(s, key);
   }
@@ -121,11 +128,7 @@ function Interface(input, output, completer, terminal) {
 
     // input usually refers to stdin
     input.on('keypress', onkeypress);
-    input.on('end', function inputEnd() {
-      if (util.isString(self.line) && self.line.length > 0)
-        self.emit('line', self.line);
-      self.close();
-    });
+    input.on('end', ontermend);
 
     // Current line
     this.line = '';
@@ -142,6 +145,7 @@ function Interface(input, output, completer, terminal) {
     output.on('resize', onresize);
     self.once('close', function() {
       input.removeListener('keypress', onkeypress);
+      input.removeListener('end', ontermend);
       output.removeListener('resize', onresize);
     });
   }

diff --git a/test/simple/test-readline-interface.js b/test/simple/test-readline-interface.js
index 930cf22..abd3681 100644 (file)
--- a/test/simple/test-readline-interface.js
+++ b/test/simple/test-readline-interface.js
@@ -35,6 +35,14 @@ FakeInput.prototype.pause = function() {};
 FakeInput.prototype.write = function() {};
 FakeInput.prototype.end = function() {};
 
+function isWarned(emitter) {
+  for (var name in emitter) {
+    var listeners = emitter[name];
+    if (listeners.warned) return true;
+  }
+  return false;
+}
+
 [ true, false ].forEach(function(terminal) {
   var fi;
   var rli;
@@ -262,4 +270,17 @@ FakeInput.prototype.end = function() {};
   assert.equal(readline.getStringWidth('> '), 2);
 
   assert.deepEqual(fi.listeners(terminal ? 'keypress' : 'data'), []);
+
+  // check EventEmitter memory leak
+  for (var i=0; i<12; i++) {
+    var rl = readline.createInterface({
+      input: process.stdin,
+      output: process.stdout
+    });
+    rl.close();
+    assert.equal(isWarned(process.stdin._events), false);
+    assert.equal(isWarned(process.stdout._events), false);
+  }
+
 });
+