Added support to not send responses when the handler has already called finish()

maintenance.md

@@ -19,3 +19,4 @@
     * `nosetests --with-cov --cov-report term-missing --cov tornado_json tests/`
     * With `tox>=1.8.0` installed for both py27 and py34
         * `sudo tox  # runs test matrix with py27,py34 and tornado322,402`
+

tests/test_tornado_json.py

@@ -160,12 +160,13 @@ class TestJSendMixin(TestTornadoJSONBase):
     class MockJSendMixinRH(jsend.JSendMixin):
         """Mock handler for testing JSendMixin"""
         _buffer = None
+        _finished = False
 
         def write(self, data):
             self._buffer = data
 
         def finish(self):
-            pass
+            self._finished = True
 
     @classmethod
     @pytest.fixture(scope="class", autouse=True)

tornado_json/jsend.py

@@ -17,8 +17,9 @@ def success(self, data):
         :param data: Acts as the wrapper for any data returned by the API
             call. If the call returns no data, data should be set to null.
         """
-        self.write({'status': 'success', 'data': data})
-        self.finish()
+        if not self._finished:
+            self.write({'status': 'success', 'data': data})
+            self.finish()
 
     def fail(self, data):
         """There was a problem with the data submitted, or some pre-condition
@@ -29,8 +30,9 @@ def fail(self, data):
             failed. If the reasons for failure correspond to POST values,
             the response object's keys SHOULD correspond to those POST values.
         """
-        self.write({'status': 'fail', 'data': data})
-        self.finish()
+        if not self._finished:
+            self.write({'status': 'fail', 'data': data})
+            self.finish()
 
     def error(self, message, data=None, code=None):
         """An error occurred in processing the request, i.e. an exception was
@@ -46,10 +48,11 @@ def error(self, message, data=None, code=None):
         :type  code: int
         :param code: A numeric code corresponding to the error, if applicable
         """
-        result = {'status': 'error', 'message': message}
-        if data:
-            result['data'] = data
-        if code:
-            result['code'] = code
-        self.write(result)
-        self.finish()
+        if not self._finished:
+            result = {'status': 'error', 'message': message}
+            if data:
+                result['data'] = data
+            if code:
+                result['code'] = code
+            self.write(result)
+            self.finish()