context.onerror: fix response handling

closes #199

lib/context.js

@@ -115,6 +115,9 @@ var proto = module.exports = {
     // delegate
     this.app.emit('error', err, this);
 
+    // unset all headers
+    this.res._headers = {};
+
     // force text/plain
     this.type = 'text';
 
@@ -128,6 +131,7 @@ var proto = module.exports = {
     var code = http.STATUS_CODES[err.status];
     var msg = err.expose ? err.message : code;
     this.status = err.status;
+    this.length = Buffer.byteLength(msg);
     this.res.end(msg);
   }
 };

test/context/onerror.js

@@ -0,0 +1,53 @@
+
+var koa = require('../..');
+var request = require('supertest');
+
+describe('ctx.onerror(err)', function(){
+  it('should respond', function(done){
+    var app = koa();
+
+    app.use(function *(next){
+      this.body = 'something else';
+
+      this.throw(499, 'boom');
+    })
+
+    var server = app.listen();
+
+    request(server)
+    .get('/')
+    .expect(499)
+    .expect('Content-Type', 'text/plain; charset=utf-8')
+    .expect('Content-Length', '4')
+    .end(done);
+  })
+
+  it('should unset all headers', function(done){
+    var app = koa();
+
+    app.use(function *(next){
+      this.set('Vary', 'Accept-Encoding');
+      this.set('X-CSRF-Token', 'asdf');
+      this.body = 'response';
+
+      this.throw(499, 'boom');
+    })
+
+    var server = app.listen();
+
+    request(server)
+    .get('/')
+    .expect(499)
+    .expect('Content-Type', 'text/plain; charset=utf-8')
+    .expect('Content-Length', '4')
+    .end(function(err, res){
+      if (err) return done(err);
+
+      res.headers.should.not.have.property('vary');
+      res.headers.should.not.have.property('x-csrf-token');
+      res.headers.should.not.have.property('x-powered-by');
+
+      done();
+    })
+  })
+})