Add support of custom errors coming from providers

Fix #431. The inherent function "raise_from_error" is called when "error=" is found in the payload. So it MUST raise something, and until now, only RFC errors were raised.

2 files changed, 16 insertions, 0 deletions

diff --git a/oauthlib/oauth2/rfc6749/errors.py b/oauthlib/oauth2/rfc6749/errors.py
index 5a0cca2..8882ab2 100644
--- a/oauthlib/oauth2/rfc6749/errors.py
+++ b/oauthlib/oauth2/rfc6749/errors.py
@@ -313,6 +313,7 @@ class ConsentRequired(OAuth2Error):
     error = 'consent_required'
     status_code = 401
 
+
 class LoginRequired(OAuth2Error):
     """
     The Authorization Server requires End-User authentication.
@@ -325,6 +326,16 @@ class LoginRequired(OAuth2Error):
     status_code = 401
 
 
+class CustomOAuth2Error(OAuth2Error):
+    """
+    This error is a placeholder for all custom errors not described by the RFC.
+    Some of the popular OAuth2 providers are using custom errors.
+    """
+    def __init__(self, error, *args, **kwargs):
+        self.error = error
+        super().__init__(*args, **kwargs)
+
+
 def raise_from_error(error, params=None):
     import inspect
     import sys
@@ -336,3 +347,4 @@ def raise_from_error(error, params=None):
     for _, cls in inspect.getmembers(sys.modules[__name__], inspect.isclass):
         if cls.error == error:
             raise cls(**kwargs)
+    raise CustomOAuth2Error(error=error, **kwargs)
diff --git a/tests/oauth2/rfc6749/test_parameters.py b/tests/oauth2/rfc6749/test_parameters.py
index b211d1e..c42f516 100644
--- a/tests/oauth2/rfc6749/test_parameters.py
+++ b/tests/oauth2/rfc6749/test_parameters.py
@@ -103,6 +103,7 @@ class ParameterTests(TestCase):
                      '  "refresh_token": "tGzv3JOkF0XG5Qx2TlKWIA",'
                      '  "example_parameter": "example_value" }')
 
+    json_custom_error = '{ "error": "incorrect_client_credentials" }'
     json_error = '{ "error": "access_denied" }'
 
     json_notoken = ('{ "token_type": "example",'
@@ -197,6 +198,9 @@ class ParameterTests(TestCase):
         self.assertRaises(ValueError, parse_implicit_response,
                 self.implicit_wrongstate, state=self.state)
 
+    def test_custom_json_error(self):
+        self.assertRaises(CustomOAuth2Error, parse_token_response, self.json_custom_error)
+
     def test_json_token_response(self):
         """Verify correct parameter parsing and validation for token responses. """
         self.assertEqual(parse_token_response(self.json_response), self.json_dict)