Honor types in dependencies (#735)

* Install the project and dependencies in 'types'. Ref #733.

* Cast parameters to match keyring's expectations.

* Bump requirement on keyring in typechecks

* Remove ignores for importlib_metadata and keyring, both typed.

mypy.ini

@@ -22,14 +22,6 @@ strict_equality = True
 ; https://github.com/tartley/colorama/issues/206
 ignore_missing_imports = True
 
-[mypy-importlib_metadata]
-; https://github.com/python/importlib_metadata/issues/10
-ignore_missing_imports = True
-
-[mypy-keyring]
-; https://github.com/jaraco/keyring/issues/437
-ignore_missing_imports = True
-
 [mypy-pkginfo]
 ; https://bugs.launchpad.net/pkginfo/+bug/1876591
 ignore_missing_imports = True

tox.ini

@@ -69,10 +69,11 @@ commands =
     flake8 twine/ tests/
 
 [testenv:types]
-skip_install = True
 deps =
     mypy
     lxml
+    # required for more thorough type declarations
+    keyring >= 22.3
 commands =
     mypy --html-report mypy --txt-report mypy {posargs:twine}
     python -c 'with open("mypy/index.txt") as f: print(f.read())'

twine/auth.py

@@ -55,7 +55,8 @@ def system(self) -> Optional[str]:
 
     def get_username_from_keyring(self) -> Optional[str]:
         try:
-            creds = keyring.get_credential(self.system, None)
+            system = cast(str, self.system)
+            creds = keyring.get_credential(system, None)
             if creds:
                 return cast(str, creds.username)
         except AttributeError:
@@ -67,7 +68,9 @@ def get_username_from_keyring(self) -> Optional[str]:
 
     def get_password_from_keyring(self) -> Optional[str]:
         try:
-            return cast(str, keyring.get_password(self.system, self.username))
+            system = cast(str, self.system)
+            username = cast(str, self.username)
+            return cast(str, keyring.get_password(system, username))
         except Exception as exc:
             warnings.warn(str(exc))
         return None