add err.status support. Closes #20

lib/application.js

@@ -125,7 +125,7 @@ app.callback = function(){
     var ctx = new self.Context(self, req, res);
 
     function done(err) {
-      if (err) ctx.error(err);
+      if (err) ctx.onerror(err);
     }
 
     co.call(ctx, function *(){
@@ -134,6 +134,17 @@ app.callback = function(){
   }
 };
 
+/**
+ * Default error handler.
+ *
+ * @param {Error} err
+ * @api private
+ */
+
+app.onerror = function(err){
+  if (this.outputErrors) console.error(err.stack);
+};
+
 /**
  * Response middleware.
  */

lib/context.js

@@ -545,10 +545,20 @@ module.exports = {
    * @api private
    */
 
-  error: function(err){
-    if (this.app.outputErrors) console.error(err.stack);
-    // TODO: change name
-    // TODO: header sent check
+  onerror: function(err){
+    // nothing we can do here other
+    // than delegate to the app-level
+    // handler and log.
+    if (this.headerSent) return this.app.onerror(err);
+
+    // err.status support
+    if (err.status) {
+      this.status = err.status;
+      this.res.end(http.STATUS_CODES[err.status]);
+      return;
+    }
+
+    // respond
     this.status = 500;
     this.res.end('Internal Server Error');
   },

test/application.js

@@ -205,6 +205,25 @@ describe('app.respond', function(){
   })
 
   describe('when an error occurs', function(){
+    describe('with a .status property', function(){
+      it('should respond with .status', function(done){
+        var app = koa();
+
+        app.use(function(next){
+          return function *(){
+            var err = new Error('s3 explodes');
+            err.status = 403;
+            throw err;
+          }
+        });
+
+        request(app.listen())
+        .get('/')
+        .expect(403, 'Forbidden')
+        .end(done);
+      })
+    })
+
     it('should respond with 500', function(done){
       var app = koa();