From 512890bb764c194b8e706011b83b3479799f1c06 Mon Sep 17 00:00:00 2001
From: Maximilian Antoni <mail@maxantoni.de>
Date: Sun, 4 Aug 2013 22:02:43 +0200
Subject: [PATCH] Handle exceptions in filters

---
 lib/hub.js             | 13 +++++++++----
 test/test-addFilter.js | 28 ++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/lib/hub.js b/lib/hub.js
index a62afb4..62c3c85 100644
--- a/lib/hub.js
+++ b/lib/hub.js
@@ -134,11 +134,16 @@ function matcherIndex(arr, event) {
   return -1;
 }
 
-function chain(filter, next) {
+function chain(filter, then) {
   return function (scope, re, callback) {
-    filter.call(scope, function (cb) {
-      next(scope, re, cb || callback);
-    }, callback);
+    function next(cb) {
+      then(scope, re, cb || callback);
+    }
+    try {
+      filter.call(scope, next, callback);
+    } catch (e) {
+      callback(e);
+    }
   };
 }
 
diff --git a/test/test-addFilter.js b/test/test-addFilter.js
index b127332..14bed28 100644
--- a/test/test-addFilter.js
+++ b/test/test-addFilter.js
@@ -265,6 +265,34 @@ test('hub.addFilter', {
     this.hub.emit('test.b');
 
     sinon.assert.calledTwice(spy);
+  },
+
+  'yields error if filter throws': function () {
+    var spy = sinon.spy();
+    var err = new Error('ouch');
+    this.hub.addFilter('test', function () {
+      throw err;
+    });
+
+    this.hub.emit('test', spy);
+
+    sinon.assert.calledOnce(spy);
+    sinon.assert.calledWith(spy, err);
+  },
+
+  'does not invoke next filter or listeners if filter throws': function () {
+    var filter   = sinon.spy(function (next) { next(); });
+    var listener = sinon.spy();
+    this.hub.addFilter('test', function () {
+      throw new Error('ouch');
+    });
+    this.hub.addFilter('test', filter);
+    this.hub.addListener('test', listener);
+
+    this.hub.emit('test', function () {});
+
+    sinon.assert.notCalled(filter);
+    sinon.assert.notCalled(listener);
   }
 
 });