Introduce more types

pyproject.toml

@@ -72,6 +72,8 @@ source_pkgs = ["molecule"]
 
 [tool.mypy]
 cache_dir = "./.cache/.mypy"
+# To ensure that calling `mypy .` produces desired results (vscode)
+exclude = ["build"]
 files = ["src", "tests"]
 strict = true
 

src/molecule/api.py

@@ -4,20 +4,22 @@
 import traceback
 
 from collections import UserList
-from typing import Any
+from collections.abc import Hashable
+from typing import Any, TypeVar, overload
 
 import pluggy
 
 from ansible_compat.ports import cache
 
-from molecule.driver.base import Driver  # noqa: F401
-from molecule.verifier.base import Verifier  # noqa: F401
+from molecule.driver.base import Driver
+from molecule.verifier.base import Verifier
 
 
 LOG = logging.getLogger(__name__)
+K = TypeVar("K", bound=Hashable)
 
 
-class UserListMap(UserList):  # type: ignore[type-arg]
+class CustomListMap(UserList[K]):
     """A list where you can also access elements by their name.
 
     Example:
@@ -26,20 +28,37 @@ class UserListMap(UserList):  # type: ignore[type-arg]
     foo.boo
     """
 
-    def __getitem__(self, i):  # type: ignore[no-untyped-def]  # noqa: ANN001, ANN204
+    @overload
+    def __getitem__(self, i: int) -> K:
         """Implement indexing."""
         if isinstance(i, int):
             return super().__getitem__(i)
         return self.__dict__[i]
 
-    def get(self, key, default):  # type: ignore[no-untyped-def]  # noqa: ANN001, ANN201, D102
-        return self.__dict__.get(key, default)
+    @overload
+    def __getitem__(self, i: Any):  # type: ignore[no-untyped-def]
+        return super().__getitem__(i)
 
-    def append(self, item) -> None:  # type: ignore[no-untyped-def]  # noqa: ANN001, D102
+    def get(self, key, default: K) -> K:  # type: ignore[no-untyped-def]  # noqa: ANN001
+        """Returns a driver by name."""
+        result = self.__dict__.get(key, default)
+        # if not isinstance(result, K):
+        #     msg = "Unable to retrieve driver."
+        #     raise KeyError(msg)
+        return result
+
+    def append(self, item) -> None:  # type: ignore[no-untyped-def]  # noqa: ANN001
+        """Add a new driver."""
         self.__dict__[str(item)] = item
         super().append(item)
 
 
+class DriverListMap(CustomListMap[Driver]): ...
+
+
+class VerifierListMap(CustomListMap[Verifier]): ...
+
+
 class MoleculeRuntimeWarning(RuntimeWarning):
     """A runtime warning used by Molecule and its plugins."""
 
@@ -49,13 +68,13 @@ class IncompatibleMoleculeRuntimeWarning(MoleculeRuntimeWarning):
 
 
 @cache
-def drivers(config: Any | None = None) -> UserListMap:  # noqa: ANN401
+def drivers(config: Any | None = None) -> DriverListMap:  # noqa: ANN401
     """Return list of active drivers.
 
     Args:
         config: plugin config
     """
-    plugins = UserListMap()
+    plugins = DriverListMap()
     pm = pluggy.PluginManager("molecule.driver")
     try:
         pm.load_setuptools_entrypoints("molecule.driver")
@@ -73,9 +92,9 @@ def drivers(config: Any | None = None) -> UserListMap:  # noqa: ANN401
 
 
 @cache
-def verifiers(config=None) -> UserListMap:  # type: ignore[no-untyped-def]  # noqa: ANN001
+def verifiers(config=None) -> VerifierListMap:  # type: ignore[no-untyped-def]  # noqa: ANN001
     """Return list of active verifiers."""
-    plugins = UserListMap()
+    plugins = VerifierListMap()
     pm = pluggy.PluginManager("molecule.verifier")
     try:
         pm.load_setuptools_entrypoints("molecule.verifier")
@@ -90,3 +109,14 @@ def verifiers(config=None) -> UserListMap:  # type: ignore[no-untyped-def]  # no
             LOG.error("Failed to load %s driver: %s", pm.get_name(p), str(e))  # noqa: TRY400
     plugins.sort()
     return plugins
+
+
+__all__ = (
+    "Driver",
+    "DriverListMap",
+    "IncompatibleMoleculeRuntimeWarning",
+    "MoleculeRuntimeWarning",
+    "Verifier",
+    "drivers",
+    "verifiers",
+)

src/molecule/command/drivers.py

@@ -45,10 +45,8 @@ def drivers(ctx, format):  # type: ignore[no-untyped-def] # pragma: no cover  #
     """List drivers."""
     drivers = []  # pylint: disable=redefined-outer-name
     for driver in api.drivers():
-        description = driver
-        if format != "plain":
-            description = driver
-        else:
+        description = str(driver)
+        if format == "plain":
             description = f"{driver!s:16s}[logging.level.notset] {driver.title} Version {driver.version} from {driver.module} python module.)[/logging.level.notset]"  # noqa: E501
         drivers.append([driver, description])
         console.print(description)

src/molecule/config.py

@@ -38,6 +38,7 @@
 from molecule.model import schema_v3
 from molecule.provisioner import ansible
 from molecule.util import boolean
+from molecule.verifier.base import Verifier
 
 
 LOG = logging.getLogger(__name__)
@@ -257,8 +258,13 @@ def state(self):  # type: ignore[no-untyped-def]  # noqa: ANN201, D102
         return state.State(self)
 
     @cached_property
-    def verifier(self):  # type: ignore[no-untyped-def]  # noqa: ANN201, D102
-        return api.verifiers(self).get(self.config["verifier"]["name"], None)  # type: ignore[no-untyped-call]
+    def verifier(self) -> Verifier:
+        """Retrieve verifiers."""
+        name = self.config["verifier"]["name"]
+        if name not in api.verifiers(self):
+            msg = f"Unable to find '{name}' verifier driver."
+            raise RuntimeError(msg)
+        return api.verifiers(self).get(name)
 
     def _get_driver_name(self):  # type: ignore[no-untyped-def] # noqa: ANN202
         # the state file contains the driver from the last run

src/molecule/driver/base.py

@@ -267,14 +267,14 @@ def get_playbook(self, step):  # type: ignore[no-untyped-def]  # noqa: ANN001, A
     def schema_file(self):  # type: ignore[no-untyped-def]  # noqa: ANN201, D102
         return None
 
-    def modules_dir(self):  # type: ignore[no-untyped-def]  # noqa: ANN201
+    def modules_dir(self) -> str | None:
         """Return path to ansible modules included with driver."""
         p = os.path.join(self._path, "modules")  # noqa: PTH118
         if os.path.isdir(p):  # noqa: PTH112
             return p
         return None
 
-    def reset(self):  # type: ignore[no-untyped-def]  # noqa: ANN201
+    def reset(self) -> None:
         """Release all resources owned by molecule.
 
         This is a destructive operation that would affect all resources managed

src/molecule/driver/delegated.py

@@ -23,7 +23,7 @@
 import os
 
 from molecule import util
-from molecule.api import Driver  # type: ignore[attr-defined]
+from molecule.api import Driver
 from molecule.data import __file__ as data_module
 
 

src/molecule/verifier/ansible.py

@@ -23,7 +23,7 @@
 import os
 
 from molecule import util
-from molecule.api import Verifier  # type: ignore[attr-defined]
+from molecule.api import Verifier
 
 
 log = logging.getLogger(__name__)

src/molecule/verifier/base.py

@@ -65,7 +65,7 @@ def default_env(self):  # type: ignore[no-untyped-def] # pragma: no cover  # noq
         """
 
     @abc.abstractmethod
-    def execute(self, action_args=None):  # type: ignore[no-untyped-def] # pragma: no cover  # noqa: ANN001, ANN201
+    def execute(self, action_args=None | list[str]):  # type: ignore[no-untyped-def] # pragma: no cover  # noqa: ANN001, ANN201
         """Execute ``cmd`` and returns None."""
 
     @abc.abstractmethod

src/molecule/verifier/testinfra.py

@@ -24,7 +24,7 @@
 import os
 
 from molecule import util
-from molecule.api import Verifier  # type: ignore[attr-defined]
+from molecule.api import Verifier
 
 
 LOG = logging.getLogger(__name__)

tests/unit/test_api.py

@@ -25,14 +25,14 @@
 def test_api_molecule_drivers_as_attributes():  # type: ignore[no-untyped-def]  # noqa: ANN201, D103
     results = api.drivers()
     assert hasattr(results, "default")
-    assert isinstance(results.default, api.Driver)  # type: ignore[attr-defined] # pylint:disable=no-member
+    assert isinstance(results.default, api.Driver)
 
 
 def test_api_drivers():  # type: ignore[no-untyped-def]  # noqa: ANN201, D103
     results = api.drivers()
 
     for result in results:
-        assert isinstance(result, api.Driver)  # type: ignore[attr-defined]
+        assert isinstance(result, api.Driver)
 
     assert "default" in results