Created
January 17, 2011 12:18
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fix emitter.on()/addListener()'s check for listener leak
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From 9b36eb9474fb56391f63d5d29b3c4fbebb665541 Mon Sep 17 00:00:00 2001 | |
From: koichik <koichik@improvement.jp> | |
Date: Mon, 17 Jan 2011 19:30:43 +0900 | |
Subject: [PATCH] fix emitter.on()/addListener()'s check for listener leak | |
Because the check is performed before a listener is added to an array, | |
the warning occurred with the 12th listener not the 11th listener. | |
example: | |
var emitter = new events.EventEmitter(); | |
for (var i = 0; i < 10; i++) { | |
emitter.on('data', function() {}); | |
} | |
emitter.on('data', function() {}); // 11th, no warning | |
emitter.on('data', function() {}); // 12th, warning occurred | |
--- | |
lib/events.js | 5 +-- | |
.../test-event-emitter-check-listener-leaks.js | 29 ++++++++++++++++++++ | |
2 files changed, 31 insertions(+), 3 deletions(-) | |
create mode 100644 test/simple/test-event-emitter-check-listener-leaks.js | |
diff --git a/lib/events.js b/lib/events.js | |
index 6505606..c5856c7 100644 | |
--- a/lib/events.js | |
+++ b/lib/events.js | |
@@ -82,6 +82,8 @@ EventEmitter.prototype.addListener = function(type, listener) { | |
// Optimize the case of one listener. Don't need the extra array object. | |
this._events[type] = listener; | |
} else if (isArray(this._events[type])) { | |
+ // If we've already got an array, just append. | |
+ this._events[type].push(listener); | |
// Check for listener leak | |
if (!this._events[type].warned) { | |
@@ -101,9 +103,6 @@ EventEmitter.prototype.addListener = function(type, listener) { | |
console.trace(); | |
} | |
} | |
- | |
- // If we've already got an array, just append. | |
- this._events[type].push(listener); | |
} else { | |
// Adding the second element, need to change to array. | |
this._events[type] = [this._events[type], listener]; | |
diff --git a/test/simple/test-event-emitter-check-listener-leaks.js b/test/simple/test-event-emitter-check-listener-leaks.js | |
new file mode 100644 | |
index 0000000..66e257c | |
--- /dev/null | |
+++ b/test/simple/test-event-emitter-check-listener-leaks.js | |
@@ -0,0 +1,29 @@ | |
+var assert = require('assert'); | |
+var events = require('events'); | |
+ | |
+var e = new events.EventEmitter(); | |
+ | |
+// default | |
+for (var i = 0; i < 10; i++) { | |
+ e.on('default', function() {}); | |
+} | |
+assert.ok(!e._events['default'].hasOwnProperty('warned')); | |
+e.on('default', function() {}); | |
+assert.ok(e._events['default'].warned); | |
+ | |
+// specific | |
+e.setMaxListeners(5); | |
+for (var i = 0; i < 5; i++) { | |
+ e.on('specific', function() {}); | |
+} | |
+assert.ok(!e._events['specific'].hasOwnProperty('warned')); | |
+e.on('specific', function() {}); | |
+assert.ok(e._events['specific'].warned); | |
+ | |
+// unlimited | |
+e.setMaxListeners(0); | |
+for (var i = 0; i < 1000; i++) { | |
+ e.on('unlimited', function() {}); | |
+} | |
+assert.ok(!e._events['unlimited'].hasOwnProperty('warned')); | |
+ | |
-- | |
1.7.1 | |
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