Make `Algorithm` an abstract base class (#845)

* Make `Algorithm` an abstract base class

This also removes some tests that are not relevant anymore

Raise `NotImplementedError` for `NoneAlgorithm`

* Use `hasattr` instead of `getattr`

* Only allow `dict` in `encode`

1 files changed, 3 insertions, 3 deletions

diff --git a/tests/test_api_jws.py b/tests/test_api_jws.py
index 2929215..d2aa915 100644
--- a/tests/test_api_jws.py
+++ b/tests/test_api_jws.py
@@ -3,7 +3,7 @@ from decimal import Decimal
 
 import pytest
 
-from jwt.algorithms import Algorithm, has_crypto
+from jwt.algorithms import NoneAlgorithm, has_crypto
 from jwt.api_jws import PyJWS
 from jwt.exceptions import (
     DecodeError,
@@ -39,10 +39,10 @@ def payload():
 
 class TestJWS:
     def test_register_algo_does_not_allow_duplicate_registration(self, jws):
-        jws.register_algorithm("AAA", Algorithm())
+        jws.register_algorithm("AAA", NoneAlgorithm())
 
         with pytest.raises(ValueError):
-            jws.register_algorithm("AAA", Algorithm())
+            jws.register_algorithm("AAA", NoneAlgorithm())
 
     def test_register_algo_rejects_non_algorithm_obj(self, jws):
         with pytest.raises(TypeError):