diff --git a/sanic/server.py b/sanic/server.py
index 2e1248d4..350e4c1b 100644
--- a/sanic/server.py
+++ b/sanic/server.py
@@ -150,10 +150,7 @@ class HttpProtocol(asyncio.Protocol):
                 self._request_stream_task.cancel()
             if self._request_handler_task:
                 self._request_handler_task.cancel()
-            try:
-                raise RequestTimeout('Request Timeout')
-            except RequestTimeout as exception:
-                self.write_error(exception)
+            self.write_error(RequestTimeout('Request Timeout'))
 
     def response_timeout_callback(self):
         # Check if elapsed time since response was initiated exceeds our
@@ -170,10 +167,7 @@ class HttpProtocol(asyncio.Protocol):
                 self._request_stream_task.cancel()
             if self._request_handler_task:
                 self._request_handler_task.cancel()
-            try:
-                raise ServiceUnavailable('Response Timeout')
-            except ServiceUnavailable as exception:
-                self.write_error(exception)
+            self.write_error(ServiceUnavailable('Response Timeout'))
 
     def keep_alive_timeout_callback(self):
         # Check if elapsed time since last response exceeds our configured
@@ -199,8 +193,7 @@ class HttpProtocol(asyncio.Protocol):
         # memory limits
         self._total_request_size += len(data)
         if self._total_request_size > self.request_max_size:
-            exception = PayloadTooLarge('Payload Too Large')
-            self.write_error(exception)
+            self.write_error(PayloadTooLarge('Payload Too Large'))
 
         # Create parser if this is the first time we're receiving data
         if self.parser is None:
@@ -218,8 +211,7 @@ class HttpProtocol(asyncio.Protocol):
             message = 'Bad Request'
             if self._debug:
                 message += '\n' + traceback.format_exc()
-            exception = InvalidUsage(message)
-            self.write_error(exception)
+            self.write_error(InvalidUsage(message))
 
     def on_url(self, url):
         if not self.url:
@@ -233,8 +225,7 @@ class HttpProtocol(asyncio.Protocol):
         if value is not None:
             if self._header_fragment == b'Content-Length' \
                     and int(value) > self.request_max_size:
-                exception = PayloadTooLarge('Payload Too Large')
-                self.write_error(exception)
+                self.write_error(PayloadTooLarge('Payload Too Large'))
             try:
                 value = value.decode()
             except UnicodeDecodeError:
@@ -433,7 +424,7 @@ class HttpProtocol(asyncio.Protocol):
                 self.log_response(response)
             try:
                 self.transport.close()
-            except AttributeError as e:
+            except AttributeError:
                 logger.debug('Connection lost before server could close it.')
 
     def bail_out(self, message, from_error=False):
@@ -443,8 +434,7 @@ class HttpProtocol(asyncio.Protocol):
                          self.transport.get_extra_info('peername'))
             logger.debug('Exception:', exc_info=True)
         else:
-            exception = ServerError(message)
-            self.write_error(exception)
+            self.write_error(ServerError(message))
             logger.error(message)
 
     def cleanup(self):
diff --git a/tests/test_config.py b/tests/test_config.py
index 3db35f4d..14b28d46 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -15,24 +15,28 @@ def test_load_from_object(app):
     assert app.config.CONFIG_VALUE == 'should be used'
     assert 'not_for_config' not in app.config
 
+
 def test_auto_load_env():
     environ["SANIC_TEST_ANSWER"] = "42"
     app = Sanic()
     assert app.config.TEST_ANSWER == 42
     del environ["SANIC_TEST_ANSWER"]
 
+
 def test_dont_load_env():
     environ["SANIC_TEST_ANSWER"] = "42"
     app = Sanic(load_env=False)
-    assert getattr(app.config, 'TEST_ANSWER', None) == None
+    assert getattr(app.config, 'TEST_ANSWER', None) is None
     del environ["SANIC_TEST_ANSWER"]
 
+
 def test_load_env_prefix():
     environ["MYAPP_TEST_ANSWER"] = "42"
     app = Sanic(load_env='MYAPP_')
     assert app.config.TEST_ANSWER == 42
     del environ["MYAPP_TEST_ANSWER"]
 
+
 def test_load_from_file(app):
     config = b"""
 VALUE = 'some value'
@@ -68,12 +72,16 @@ def test_load_from_envvar(app):
 
 
 def test_load_from_missing_envvar(app):
-    with pytest.raises(RuntimeError):
+    with pytest.raises(RuntimeError) as e:
         app.config.from_envvar('non-existent variable')
+        assert str(e.value) == ("The environment variable 'non-existent "
+                                "variable' is not set and thus configuration "
+                                "could not be loaded.")
 
 
 def test_overwrite_exisiting_config(app):
     app.config.DEFAULT = 1
+
     class Config:
         DEFAULT = 2
 
@@ -82,5 +90,6 @@ def test_overwrite_exisiting_config(app):
 
 
 def test_missing_config(app):
-    with pytest.raises(AttributeError):
+    with pytest.raises(AttributeError) as e:
         app.config.NON_EXISTENT
+        assert str(e.value) == ("Config has no 'NON_EXISTENT'")