Handle config error in load config file.

sanic/config.py

@@ -1,6 +1,8 @@
 import os
 import types
 
+from sanic.exceptions import PyFileError
+
 
 SANIC_PREFIX = 'SANIC_'
 
@@ -83,6 +85,9 @@ class Config(dict):
         except IOError as e:
             e.strerror = 'Unable to load configuration file (%s)' % e.strerror
             raise
+        except Exception as e:
+            raise PyFileError(filename) from e
+
         self.from_object(module)
         return True
 

sanic/exceptions.py

@@ -223,6 +223,11 @@ class InvalidRangeType(ContentRangeError):
     pass
 
 
+class PyFileError(Exception):
+    def __init__(self, file):
+        super().__init__('could not execute config file %s', file)
+
+
 @add_status_code(401)
 class Unauthorized(SanicException):
     """

tests/test_config.py

@@ -3,6 +3,7 @@ import pytest
 from tempfile import NamedTemporaryFile
 
 from sanic import Sanic
+from sanic.exceptions import PyFileError
 
 
 def test_load_from_object(app):
@@ -79,6 +80,16 @@ def test_load_from_missing_envvar(app):
                                 "could not be loaded.")
 
 
+def test_load_config_from_file_invalid_syntax(app):
+    config = b"VALUE = some value"
+    with NamedTemporaryFile() as config_file:
+        config_file.write(config)
+        config_file.seek(0)
+
+        with pytest.raises(PyFileError):
+            app.config.from_pyfile(config_file.name)
+
+
 def test_overwrite_exisiting_config(app):
     app.config.DEFAULT = 1