bugfix

satella/configuration/sources/envvars.py

@@ -26,7 +26,7 @@ class EnvironmentSource(BaseSource):
         self.config_name = config_name or env_name
         self.cast_to = cast_to
 
-    @rethrow_as([ValueError, TypeError, KeyError], ConfigurationError)
+    @rethrow_as((ValueError, TypeError, KeyError), ConfigurationError)
     def provide(self) -> dict:
         v = self.cast_to(os.environ[self.env_name])
 

tests/test_configuration/test_sources/test_envvars.py

-from satella.configuration.sources import EnvVarsSource, OptionalSource
+from satella.configuration.sources import EnvVarsSource, OptionalSource, AlternativeSource, EnvironmentSource, \
+    StaticSource
 from .utils import SourceTestCase, mock_env
 
 
@@ -10,3 +11,10 @@ class TestEnvVarsSource(SourceTestCase):
     def test_none(self):
         self.assertSourceEmpty(OptionalSource(EnvVarsSource('satella')))
         self.assertSourceFails(EnvVarsSource('satella'))
+
+    def test_alternative(self):
+        ds = AlternativeSource(
+            EnvironmentSource('test', 'test'),
+            StaticSource({'test': 'test'})
+        )
+        self.assertSourceHas(ds, {'test': 'test'})
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