ajacksified#25

Elergy · May 2, 2014 · 9aecd60 · 9aecd60
1 parent acdeaf6
commit 9aecd60
Show file tree

Hide file tree

Showing 2 changed files with 62 additions and 4 deletions.
diff --git a/lib/mediator.js b/lib/mediator.js
@@ -200,7 +200,8 @@
           y = this._subscribers.length,
           called = false,
           subscriber, l,
-          subsBefore,subsAfter;
+          subsBefore,subsAfter,
+          predicateResult;
 
       // Priority is preserved in the _subscribers index.
       for(x, y; x < y; x++) {
@@ -209,13 +210,27 @@
         if(!this.stopped){
           subscriber = this._subscribers[x];
           if(subscriber.options !== undefined && typeof subscriber.options.predicate === "function"){
-            if(subscriber.options.predicate.apply(subscriber.context, data)){
-              subscriber.fn.apply(subscriber.context, data);
+            try {
+              predicateResult = subscriber.options.predicate.apply(subscriber.context, data);
+            } catch (ex) {
+              predicateResult = false;
+              this._processException(ex);
+            }
+            if(predicateResult){
+              try {
+                subscriber.fn.apply(subscriber.context, data);
+              } catch(ex) {
+                this._processException(ex);
+              }
               called = true;
             }
           }else{
             subsBefore = this._subscribers.length;
-            subscriber.fn.apply(subscriber.context, data);
+            try {
+              subscriber.fn.apply(subscriber.context, data);
+            } catch(ex) {
+              this._processException(ex);
+            }
             subsAfter = this._subscribers.length;
             y = subsAfter;
             if (subsAfter === subsBefore - 1){
@@ -241,6 +256,22 @@
       }
 
       this.stopped = false;
+    },
+
+    //Throw an exception in another context through setImmediate of setTimeout.
+    //If neither setImmediate nor setTimeout is defined we log exception's stack to the console (if it is defined)
+    _processException: function(ex) {
+      if (typeof setImmediate === 'function') {
+        setImmediate(function() {
+          throw ex;
+        });
+      } else if (typeof setTimeout === 'function') {
+        setTimeout(function() {
+          throw ex;
+        }, 0);
+      } else if (typeof console !== "undefined" && console.log) {
+        console.log(ex.stack);
+      }
     }
   };
 

diff --git a/test/ChannelSpec.js b/test/ChannelSpec.js
@@ -299,5 +299,32 @@ describe("Channel", function() {
       expect(this.a).to.equal("0123");
     });
 
+    it("should  call subscribers and continue running, if one of subscribers throws an exception", function(){
+      var sub1 = function(){
+          this.a += "1";
+        },
+        sub2 = function(){
+          this.a += "2";
+          throw new Error('error');
+          this.a += "444";
+        },
+        sub3 = function(){
+          this.a += "3";
+        },
+        data = ["data"];
+      this.a = "0";
+
+      channel.addSubscriber(sub1, {}, this);
+      channel.addSubscriber(sub2, {}, this);
+      channel.addSubscriber(sub3, {}, this);
+      try {
+        channel.publish(data);
+        this.a += "4";
+      } catch(ex) {
+        this.a += "555";
+      }
+      expect(this.a).to.equal("01234");
+    });
+
   });
 });