Added a helpful exception when stats file is not valid

Author: owais

MANIFEST

@@ -4,6 +4,7 @@ setup.cfg
 setup.py
 webpack_loader/__init__.py
 webpack_loader/apps.py
+webpack_loader/errors.py
 webpack_loader/signals.py
 webpack_loader/utils.py
 webpack_loader/contrib/__init__.py

setup.py

@@ -1,6 +1,6 @@
 from distutils.core import setup
 
-version = '0.2.0'
+version = '0.2.1'
 
 setup(
  name = 'django-webpack-loader',

webpack_loader/utils.py

@@ -31,7 +31,11 @@
  entry['ignores'] = [re.compile(I) for I in entry['IGNORE']]
 
 
-class WebpackException(BaseException):
+class WebpackError(BaseException):
+ pass
+
+
+class WebpackLoaderBadStatsError(BaseException):
  pass
 
 
@@ -79,4 +83,9 @@ def get_bundle(bundle_name, config):
  {error} in {file}
  {message}
  """.format(**assets)
- raise WebpackException(error)
+ raise WebpackError(error)
+
+ raise WebpackLoaderBadStatsError(
+ "The stats file does not contain valid data. Make sure "
+ "webpack-bundle-tracker plugin is enabled and try to run "
+ "webpack again.")