If no such issuer return None.

Author: rohe

src/cryptojwt/key_jar.py

@@ -364,7 +364,7 @@ def find(self, source, issuer_id=None):
         else:
             _issuer = self._get_issuer(issuer_id)
             if _issuer is None:
-                return []
+                return None
             else:
                 res = _issuer.find(source)
 

tests/test_04_key_jar.py

@@ -773,7 +773,7 @@ def test_find():
 
     assert kj.find('{}'.format(_path), 'Alice')
     assert kj.find('https://example.com', 'Alice') == []
-    assert kj.find('{}'.format(_path), 'Bob') == []
+    assert kj.find('{}'.format(_path), 'Bob') is None
 
 
 def test_get_decrypt_keys():