fix(jwt): update claims validation logic, allow value to be False or 0

ref: #23

src/joserfc/rfc7519/registry.py

@@ -27,15 +27,15 @@ def check_value(self, claim_name: str, value: Any) -> None:
         option = self.options.get(claim_name)
         if option:
             allow_blank = option.get("allow_blank")
-            if not allow_blank and not value:
+            if not allow_blank and value == "":
                 raise InvalidClaimError(claim_name)
 
             option_value = option.get("value")
-            if option_value and value != option_value:
+            if option_value is not None and value != option_value:
                 raise InvalidClaimError(claim_name)
 
             option_values = option.get("values")
-            if option_values and value not in option_values:
+            if option_values is not None and value not in option_values:
                 raise InvalidClaimError(claim_name)
 
     def validate(self, claims: Dict[str, Any]) -> None:

tests/jwt/test_claims.py

@@ -56,6 +56,11 @@ def test_essential_empty_value(self):
         self.assertRaises(MissingClaimError, claims_requests.validate, {"sub": None})
         claims_requests.validate({"sub": ""})
 
+    def test_essential_false_value(self):
+        claims_requests = jwt.JWTClaimsRegistry(foo={"essential": True})
+        claims_requests.validate({"foo": False})
+        claims_requests.validate({"foo": 0})
+
     def test_option_value(self):
         claims_requests = jwt.JWTClaimsRegistry(sub={"essential": True, "value": "123"})
         self.assertRaises(InvalidClaimError, claims_requests.validate, {"sub": "a"})