Allow updating to v6 method signature for ENS.resolver()

Author: fselmo

ens/main.py

@@ -280,15 +280,22 @@ def resolve(self, name: str, get: str = 'addr') -> Optional[Union[ChecksumAddres
         else:
             return None
 
-    def resolver(self, normal_name: str, name: str = None) -> Optional['Contract']:
+    def resolver(self, normal_name: str = None, name: str = None) -> Optional['Contract']:
         if not name:
             warnings.warn(
                 "The function signature for resolver() will change in v6 to accept `name` as a "
                 "the positional argument, over `normal_name`, and the method will instead "
-                "normalize the name internally. To suppress warnings for now, `name` may be passed "
-                "in as a keyword argument.",
+                "normalize the name internally. You may migrate to using `name` by passing it in "
+                "as a keyword, e.g. resolver(name=\"ensname.eth\").",
                 category=FutureWarning,
             )
+        else:
+            if normal_name:
+                raise TypeError(
+                    "Only supply one positional argument or the `name` keyword, e.g. "
+                    "resolver(\"ensname.eth\") or resolver(name=\"ensname.eth\")."
+                )
+            normal_name = normalize_name(name)
 
         resolver_addr = self.ens.caller.resolver(normal_name_to_hash(normal_name))
         if is_none_or_zero_address(resolver_addr):

tests/ens/test_v6_warnings.py

@@ -10,20 +10,28 @@ def test_resolve_deprecation_warning(ens):
             "`ENS.address\\(\\)` for forward resolution, and `ENS.name\\(\\)` for reverse "
             "resolution instead."
     ):
-        ens.resolve('tester.eth')
+        ens.resolve("tester.eth")
 
 
-def test_resolver_future_warning(ens):
+def test_resolver_future_warning_when_name_is_missing(ens):
     with pytest.warns(
         FutureWarning,
         match="The function signature for resolver\\(\\) will change in v6 to accept `name` as a "
             "the positional argument, over `normal_name`, and the method will instead "
-            "normalize the name internally. To suppress warnings for now, `name` may be passed "
-            "in as a keyword argument.",
+            "normalize the name internally. You may migrate to using `name` by passing it in "
+            "as a keyword, e.g. resolver\\(name=\"ensname.eth\"\\).",
     ):
-        ens.resolver('tester.eth')
+        assert ens.resolver("eth")
 
-    # assert no warning when `name` kwarg is passed in
+    # assert no warning when `name` is passed in as a kwarg
     with warnings.catch_warnings():
         warnings.simplefilter("error")  # turn all warnings to errors
-        ens.resolver('tester.eth', name='tester.eth')
+        assert ens.resolver(name="EtH")
+
+    # assert TypeError if both arguments passed in
+    with pytest.raises(
+        TypeError,
+        match="Only supply one positional argument or the `name` keyword, e.g. resolver\\("
+        "\"ensname.eth\"\\) or resolver\\(name=\"ensname.eth\"\\).",
+    ):
+        ens.resolver("eth", name="EtH")